Presentation is loading. Please wait.

Presentation is loading. Please wait.

Ferrous Metals.

Similar presentations


Presentation on theme: "Ferrous Metals."— Presentation transcript:

1 Ferrous Metals

2 Engineering Materials
Metals Ferrous Iron Steel Pig iron Cast iron Wrought iron Non-Ferrous Copper & Alloys Aluminium Zinc Tin Lead Non-Metals Rubber Plastics Resin Ceramics

3 Pure Metals and Alloys Metal that are not mixed with any other materials are known as pure metals. Metals listed in the Periodic Table are pure metals E.g. Iron (Fe), Copper (Cu) and Zinc (Zn) Alloys are mixtures of two or more metals formed together with other elements/materials to create new metals with improved Mechanical Properties and other properties of the base metal. E.g. Brass (Copper and Zinc), Stainless steel (steel and chromium) Alloy = metal A + metal B + … + other elements

4 Ferrous Metals & Non-Ferrous Metals
Ferrous metals are metals that contain iron E.g. Steel (iron and carbon) Non-ferrous metals are metals that do not contain iron E.g. Zinc (pure metal), Bronze (Copper and tin) (non-ferrous may contain slight traces of iron) Ferrous Metal = alloy metals that contains iron ( Primary base metal is iron) Non-ferrous Metal = alloy metals that do not contain iron Primary base metal does not contain iron)

5 Classification Metals can be divided into 2 groups Metals
Ferrous Metals Non- Ferrous Metals Iron Aluminum Low Carbon Steel Copper Medium Carbon Steel Brass High Carbon Steel Bronze Cast Iron Zinc Stainless Steel Lead Tool Steels Tin Others

6 METALS 07/11/ :40 م

7 STEEL Steels are alloys of iron and carbon plus other alloying elements. In steels, carbon present in atomic form, and occupies interstitial sites of Fe microstructure. Alloying additions are necessary for many reasons including: improving properties, improving corrosion resistance, etc. Arguably steels are well known and most used materials than any other materials. Mechanical properties of steels are very sensitive to carbon content. Hence, it is practical to classify steels based on their carbon content. Thus steels are basically three kinds: low-carbon steels (% wt of C < 0.3), medium carbon steels (0.3 <% wt of C < 0.6) and high-carbon steels (% wt of C > 0.6). The other parameter available for classification of steels is amount of alloying additions, and based on this steels are two kinds: (plain) carbon steels and alloy-steels.

8 Low carbon steels These are produced in the greatest quantities than other alloys. Carbon present in these alloys is limited, and is not enough to strengthen these materials by heat treatment; hence these alloys are strengthened by cold work. Their microstructure consists of ferrite and pearlite, and these alloys are thus relatively soft, ductile combined with high toughness. Hence these materials are easily machinable and weldable. Typical applications of these alloys include: structural shapes, tin cans, automobile body components, buildings, etc. A special group of ferrous alloys with noticeable amount of alloying additions are known as HSLA (high-strength low-alloy) steels. Common alloying elements are: Cu, V, Ni, W, Cr, Mo, etc. These alloys can be strengthened by heat treatment, and yet the same time they are ductile, formable. Typical applications of these HSLA steels include: support columns, bridges, pressure vessels.

9 Medium carbon steels These are stronger than low carbon steels. However these are of less ductile than low carbon steels. These alloys can be heat treated to improve their strength. Usual heat treatment cycle consists of austenitizing, quenching, and tempering at suitable conditions to acquire required hardness. They are often used in tempered condition. As hardenability of these alloys is low, only thin sections can be heat treated using very high quench rates. Ni, Cr and Mo alloying additions improve their hardenability. Typical applications include: railway tracks & wheels, gears, other machine parts which may require good combination of strength and toughness.

10 High carbon steels These are strongest and hardest of carbon steels, and of course their ductility is very limited. These are heat treatable, and mostly used in hardened and tempered conditions. They possess very high wear resistance, and capable of holding sharp edges. Thus these are used for tool application such as knives, razors, hacksaw blades, etc. With addition of alloying element like Cr, V, Mo, W which forms hard carbides by reacting with carbon present, wear resistance of high carbon steels can be improved considerably.

11 Effects of Elements in Steels
Different elements are added to steels to give the steel different properties. The elements pass on properties such as harden-ability, strength, hardness, toughness, wear resistance, etc. Some properties are beneficial while others are detrimental.

12 Effects of Elements in Steels
Alloying is changing chemical composition of steel by adding elements with purpose to improve its properties as compared to the plane carbon steel. These elements lower the solubility of carbon in austenite, causing increase of amount of carbides in the steel. The following elements have ferrite stabilizing effect: chromium (Cr), tungsten (W), Molybdenum (Mo), vanadium (V), aluminum (Al) and silicon (Si). Examples of ferritic steels :transformer sheets steel (3%Si), F-Cr alloys. Carbide forming – elements forming hard carbides in steels. Graphitizing – decreasing stability of carbides, promoting their breaking and formation of free Graphite. The following elements have graphitizing effect: silicon (Si), nickel (Ni), cobalt (Co), aluminum (Al).

13 Effects of Elements in Steels
The elements like chromium (Cr), tungsten (W), molybdenum (Mo), vanadium (V), titanium (Ti), niobium (Nb), tantalum (Ta), zirconium (Zr) form hard (often complex) carbides, increasing steel hardness and strength. Examples of steels containing relatively high concentration of carbides: hot work tool steels, high speed steels. Carbide forming elements also form nitrides reacting with Nitrogen in steels.

14 Characteristics of alloying elements
Manganese (Mn) – improves hardenability, ductility and wear resistance, increasing strength at high temperatures. Nickel (Ni) – increases strength, impact strength and toughness, impart corrosion resistance in combination with other elements. Chromium (Cr) – improves hardenability, strength and wear resistance, sharply increases corrosion resistance at high concentrations (> 12%). Tungsten (W) – increases hardness particularly at elevated temperatures due to stable carbides, refines grain size.

15 Characteristics of alloying elements
Vanadium (V) – increases strength, hardness, creep resistance and impact resistance due to formation of hard vanadium carbides, limits grain size. Molybdenum (Mo) – increases hardenability and strength particularly at high temperatures and under dynamic conditions. Silicon (Si) – improves strength, elasticity, and promotes large grain sizes, which cause increasing magnetic permeability. Titanium (Ti) – improves strength and corrosion resistance, limits austenite grain size

16 Residual Elements During the processing of steels some residual elements remain in the metal. These residuals are trace elements that are unwanted due to their detrimental properties but cannot be extracted completely. Some of these residual elements include: antimony, arsenic, hydrogen, nitrogen, oxygen, and tin. Molten Steel

17 Types of Steel Steel Low carbon steel (mild steel) Medium carbon steel
High carbon steel (tool steels) Cast iron Alloy Steels Stainless steel High speed steel

18

19

20

21 Carbon Steels Carbon steels are group by their percentage of carbon content per weight. The higher the carbon content the greater the hardness, strength and wear resistance after heat treatment. Low-carbon steel, also called mild steels, has less than 0.30% carbon. Used in everyday industrial products like bolts, nuts, sheet, plate and tubes. High Carbon Steel Nails

22 Carbon Steels Medium-carbon steel has 0.30% to 0.60% carbon. Used for jobs requiring higher strength such as machinery, automotive equipment parts, and metalworking equipment. High-carbon steel has more than 0.60% carbon. Used parts that require the highest strength, hardness, and wear resistance. Once manufactured they are heat treated and tempered

23 Alloy Steels Alloy steels are steels that contain significant amounts of alloying elements. High strength low alloy steels Microalloyed steels Nanoalloyed steels

24 Alloy steels Alloy steels are iron-carbon alloys, to which alloying elements are added with a purpose to improve the steels properties as compared to the Carbon steels. Due to effect of alloying elements, properties of alloy steels exceed those of plane carbon steels. AISI/SAE classification divide alloy steels onto groups according to the major alloying elements: Low alloy steels (alloying elements < 8%) High alloy steels (alloying elements > 8%) According to the four-digit classification SAE/AISI system:

25 Alloy Steels Commonly used in automobile bodies and in the transportation industry (the reduced weight makes for better fuel economy ). First digit indicates the class of the alloy steel: 2- Nickel steels; Nickel-chromium steels; 4- Molybdenum steels; Chromium steels; 6- Chromium-vanadium steels; Tungsten-chromium steels; 9- Silicon-manganese steels. Second digit indicates concentration of the major element in percents (1 means 1%). Last two digits indicate carbon concentration in 0,01%. Example: SAE 5130 means alloy chromium steel, containing 1% of chromium and 0.30% of carbon.

26 High Speed Steel High-strength, low-alloy steels (HSLA) steels were developed to improve the ratio of strength to weight. Commonly used in automobile bodies and in the transportation industry (the reduced weight makes for better fuel economy ). Medium Carbon steel alloyed with Tungsten, chromium, vanadium Very hard Resistant to frictional heat even at high temperature Can only be ground Machine cutting tools (lathe and milling) Drills

27 Stainless Steels Stainless steels are primarily know for their corrosion resistance, high strength, and ductility and chromium content.

28 Stainless Steels The reason for the name stainless is due to the fact that in the presence of oxygen, the steel develops a thin, hard, adherent film of chromium. Even if the surface is scratched, the protective film is rebuilt through passivation. For passivation to occur there needs to be a minimum chromium content of 13% by weight.

29 Stainless Steels Stainless steels tend to have lower carbon content since increased carbon content lowers the corrosion resistance of stainless steels. Since the carbon reacts with chromium it decreases the available chromium content which is needed for developing the protective film. Ferritic stainless steels are principally Fe-Cr-C alloys with 12-14% Cr. They also contain small additions of Mo, V, Nb, and Ni. Austenitic stainless steels usually contain 18% Cr and 8% Ni in addition to other minor alloying elements. Ni stabilizes the austenitic phase assisted by C and N. Other alloying additions include Ti, Nb, Mo (prevent weld decay), Mn and Cu (helps in stabilizing austenite). By alloying additions, for martensitic steels Ms is made to be above the room temperature. These alloys are heat treatable. Major alloying elements are: Cr, Mn and Mo.

30 Tool steels Tool steel contains various amounts of tungsten, molybdenum, cobalt and vanadium to increase the heat resistance and durability of the metal. This makes them ideal when used for cutting and drilling. Tool Steel is divided into these six groups:  water-hardening, cold-work, shock-resisting, high-speed, hot-work, and special purpose

31 Water-hardening class 
Named from its essential property of having to be water quenched. This grade of tool steel is essentially plain high carbon steel. It is commonly used because of its low cost. Cold-work classes  Is a group of three tool steels: oil-hardening, air-hardening, and high carbon-chromium. The steels in the group have high hardenability and wear resistance, with average toughness. Typically they are in the production of larger parts or parts that have a minimum distortion requirement when being hardened. Both Oil quenching and Air-hardening both reduce the distortion and higher stress caused by the quick water quenching. Because of this they are less likely to crack. D-grade of tool steel in the cold-work class can contain approximately 10% to 13% chromium. This type of tool steel does retain its hardness at increased temperature (425 °C / 797 °F max).  The most typical applications for this type of tool steel is in forging dies, die-casting die blocks, and drawing dies. Shock-resisting class  This class has high shock resistance and good hardenability. It is designed to resist shock at both low and high temperatures. It also has a very high impact toughness and relatively low abrasion resistance. High speed class T-type and M-type tool steels are used for cutting tools when strength and hardness must be retained at high temperatures. Hot-working class  H-group tool steels were specifically developed to maintain strength and hardness while exposed to prolonged elevated temperatures. Plastic Mold & Special purpose classes P-Code (Plastic Mold Steel) – Designed to meet the needs of zinc die casting and the special requirements of plastic injection molding dies L-Code – A low alloy special purpose tool steel. F-Code – Water harden-able / more wear resistant than W-type tool steel.

32 Tool and Die Steels Tool and die steels are alloyed steels design for high strength, impact toughness, and wear resistance at normal and elevated temperatures. High-speed steels Maintain their hardness and strength at elevated operating temperatures. There are two basic types the M-series and T-series

33 Tool and Die Steels M-series contain 10 % molybdenum and have higher abrasion resistance than T- series T- Series contain 12 % to 18 % tungsten. They undergo less distortion in heat treatment and are less expensive than the M-series. M- series steel drill bits coated with titanium

34 Tool and Die Steels Dies are tools used for drawing wire, and for blanking, bending, cutting, machine forging, and embossing. . H-series (Hot-working steels) for use at elevated temperatures. They have high toughness and high resistance to wear and cracking. S-series (shock resisting steels) designed for impact toughness.

35 TRIP steels TRIP stands for Transformation Induced Plasticity
TRIP steels offer an outstanding combination of strength and ductility as a result of their microstructure. They are thus suitable for structural and reinforcement parts of complex shape. Austenite is transformed into martensite during plastic deformation making it possible to achieve greater elongations and lending these steels their excellent combination of strength and ductility. These steels have high strain hardening capacity. They exhibit good strain redistribution and thus good drawability. As a result of strain hardening, the mechanical properties, and especially the yield strength, of the finished part are far superior to those of the initial blank. High strain hardening capacity and high mechanical strength lend these steels excellent energy absorption capacity. As a result of their high energy absorption capacity and fatigue strength, TRIP steels are particularly well suited for automotive structural and safety parts such as cross members, longitudinal beams, B-pillar reinforcements, sills and bumper reinforcements

36

37

38 Applications As a result of their high energy absorption capacity and fatigue strength, TRIP steels are particularly well suited for automotive structural and safety parts such as cross members, longitudinal beams, B-pillar reinforcements, sills and bumper reinforcements.

39

40 Types of cast iron Grey cast iron - carbon as graphite
White cast iron - carbides, often alloyed Ductile cast iron nodular, spheroidal graphite Malleable cast iron Compacted graphite cast iron CG or Vermicular Iron

41 Effect of cooling rate Slow cooling favours the formation of graphite & low hardness Rapid cooling promotes carbides with high hardness Thick sections cool slowly, while thin sections cool quickly Sand moulds cool slowly, but metal chills can be used to increase cooling rate & promote white iron

42 Grey cast iron Flake graphite in a matrix of pearlite, ferrite or martensite Wide range of applications Low ductility - elongation 0.6% Grey cast iron forms when Cooling is slow, as in heavy sections High silicon or carbon

43 Matrix structure Pearlite or ferrite Transformation is to ferrite when
Cooling rate is slow High silicon content High carbon equivalence Presence of fine under cooled graphite

44 Properties of grey cast iron
Machineability is excellent Ductility is low (0.6%), impact resistance low Damping capacity high Thermal conductivity high Dry and normal wear properties excellent

45 Applications Engines Cylinder blocks, liners,
Brake drums, clutch plates Pressure pipe fittings (AS2544) Machinery beds Furnace parts, ingot and glass moulds

46

47

48

49 Nodular or Ductile Iron
Addition of Mg to grey iron converts the graphite flakes to nodules. Normally a pearlite matrix. Castings are stronger and much more ductile than grey iron as the stress concentration points existing at the flake tips are eliminated.

50 White Iron If the composition of iron is appropriate or the cooling rate of the metal is sufficiently rapid during solidification, the metal will solidify as white iron in which all carbon will combine with iron as iron carbide. This compound, also known as cementite, is hard and brittle and has a white crystalline fracture, It is essentially free of graphite. White iron has a very high compressive strength and excellent wear resistance, and it retains its hardness for limited periods even upto a red heat. White iron can be produced in selected area of a casting such as on the periphery of a cam by causing localized rapid solidification of iron. White iron at the surface of the casting is called chill. White iron does not have easy castability of the other irons because it solidification temperature is generally higher, and it solidifies with carbon in its combined form as iron carbide. Thus because of the absent of free graphite minimizing towards solidification shrinkage is absent. A casting that solidified at an intermediate rate can contain both iron carbide and graphite. This structure is called molted iron.

51 Contains 0.5 to 2% Si and lower C content
Formed by rapid cooling of the molten metal Its hard, brittle and excellent wear resistance Applications include railway brake shoes When cast iron is heat treated to separate carbon out of solution and form graphite, resulting metal is called malleable (upto 20%) Malleable cast iron is utilized for pipe fitting and flanges

52

53 Malleable Iron By a special heat-treatment of white cast iron, iron carbide is separated into iron and free graphite. The free graphite in the microstructure takes the form of irregularly shaped nodules of graphite. This form of graphite is also called temper carbon because it is formed into solid state during heat-treatment. The iron is cast as white iron of suitable chemical composition. After the castings are removed from the mould, they are given along heat-treatment starting at a temperature above 1650 (900°C). This causes the iron carbide to dissociate and the free carbon precipitates in the solid iron as graphite. The rapid solidification rate that is necessary to form the white iron limits the metal thickness in the casting. The thickness of irons that can be cast white and still be annealed is increased by addition of bismuth and tellurium to the molten metal. In general, the mechanical properties of cast iron is dependent both on the metallic matrix and the state of graphite. A wide range of mechanical properties can be obtained in melleable iron by controlling the matrix structure around the graphite, pearlite and martensitic matrices are obtained both by rapid cooling through the critical temperature and with alloy addition.

54

55 Malleable DUCTILE grey

56 Gray Iron The graphite morphology can be changed from one form to another over a wide range of graphite formations by altering the solidification cooling rate and/or the amount of nodularizing elements present such as magnesium or rare earths. When the composition of molten iron and its cooling rate are appropriate, the carbon in the iron separates during solidification and forms separate graphite flakes that are interconnected within each eutectic cell. The graphite grows edgewise into the liquid and forms the characteristic flake shape. When grey Iron Is broken, most of the fracture occurs along the graphite, thereby accounting for the characteristic grey colour of the fracture surface. Increasing cooling rate and/or increasing the effective nodularizing elements results in the following changes in the graphite formations : Type-A graphite, Type-B graphite, Type-D graphite (under cooled graphite), coral, compacted, deteriorated form of spheroidal and spheroidal graphite.

57 Gray Iron The properties of grey iron are influenced by the size, amount, and distribution of graphite flakes, and by the relative hardness of the matrix metal around the graphite. These factors are controlled mainly by the - carbon and the silicon contents of the metal and the cooling rate of the casting. Slower cooling and higher carbon and silicon contents tend to produce more and large graphite flakes, a softer matrix structure, and lower strength. The flake graphite provides grey iron with unique properties such as excellent machinability at hardness levels that produces superior wear resisting characteristics, the ability to resist galling, and excellent vibration damping resulting from a non-linear stress-strain relationship at relatively low stresses. Because of the nature of the graphite flakes in grey iron, i.e. long, flaky and interconnected with sharp tips, it has got high thermal conductivity.

58

59 Chapter 6: Nonferrous Metals and Alloys
6.1 Introduction 6.2 Aluminum 6.3 Magnesium 6.4 Copper 6.5 Nickel 6.6 Superalloys 6.7 Titanium 6.8 Refractory Metals

60 Cast Iron Contains 2%-4% of carbon Very hard and brittle
Strong under compression Suitable for casting [can be pour at a relatively low temperature] Engine block, engineer vices, machine parts

61 Unit V : Non Ferrous Metals
Nonferrous metals and their alloys do not contain iron as a principle ingredient, although they may contain small percentages. Aluminum, beryllium, and titanium are used in structural applications. Light metals such as lithium, magnesium, potassium, and sodium also have important engineering applications. Nickel and lead have widespread applications as does copper which is often chosen for its high thermal and electrical conductivity. Cadmium, tin, and zinc are often used as coatings, electrical applications, and for bearing surfaces. Cobalt and manganese are common alloying elements in steels. Gold, silver, and platinum, the precious metals, are used in electrical applications and jewelry.

62 The wrought non-heat-treatable alloys include the commercially pure aluminum alloys
(1xxx), the aluminum-manganese alloys (3xxx), the aluminum-silicon alloys (4xxx), and the aluminum-magnesium alloys (5xxx). Commercially Pure Aluminum Alloys (1xxx). The 1xxx alloys normally have tensile strengths in the range of 69 to 186 MPa (10 to 27 ksi). The 1xxx series of aluminum alloys include both the super purity grades (99.99%) and the commercially pure grades containing up to 1 wt% impurities or minor additions. The last two digits of the alloy number denote the two digits to the right of the decimal point of the percentage of the material that is aluminum. For example, 1060 denotes an alloy that is 99.60% Al. The more prevalent commercially pure grades (99.0 wt% minimum aluminum) are available in most product forms and are used for applications such as electrical conductors, chemical processing equipment, aluminum foil, cooking utensils, and architectural products. Since these alloys are essentially free of alloying additions, they exhibit excellent corrosion resistance to atmospheric conditions.

63 Aluminum-Manganese Alloys (3xxx)
The 3xxx alloys are often used where higher strength levels are required along with good ductility and excellent corrosion resistance. The aluminum manganese alloys contain up to 1.25 wt% Mn; higher amounts are avoided because the presence of iron impurities can result in the formation of large primary particles of Al6Mn, which causes embrittlement. Additions of magnesium provide improved solid-solution hardening, as in the alloy 3004, which is used for beverage cans, the highest single usage of any aluminum alloys, accounting for approximately 1/4 of the total usage of aluminum. Their moderate strength (ultimate tensile strengths of 110 to 297 MPa, or 16 to 43 ksi) often eliminates their consideration for structural applications. These alloys are welded with 1xxx-, 4xxx-, and 5xxx-series filler alloys, dependening on the specific chemistry, specific application, and service requirements Aluminum-Silicon Alloys (4xxx). The 4xxx series of alloys is not as widely used as the 3xxx and 5xxx alloys. Ultimate tensile strengths range from 172 to 379 MPa (25 to 55 ksi). Because of the relatively high silicon content, the 4xxx series has excellent flow characteristics, making them the alloys of choice for two major applications. Alloy 4032 is used for forged pistons; the high silicon content contributes to complete filling of complex dies and provides wear resistance in service. The 4xxx alloys are also used for weld and braze filler metals, where the silicon content promotes molten metal flow to fill grooves and joints during welding and brazing. Although aluminum-silicon alloys will not respond to heat treatment, some of the 4xxx alloys also contain magnesium or copper, which allows them to be hardened by precipitation heat treating.

64 Aluminum-Copper Alloys (2xxx)
The high-strength 2xxx and 7xxx alloys are competitive on a strength-to-weight ratio with the higher-strength but heavier titanium and steel alloys and thus have traditionally been the dominant structural material in both commercial and military aircraft. In addition, aluminum alloys are not embrittled at low temperatures and become even stronger as the temperature is decreased, without significant ductility losses, making them ideal for cryogenic fuel tanks for rockets and launch vehicles. The wrought heat treatable 2xxx alloys generally contain magnesium in addition to copper as an alloying element. Other significant alloying additions include titanium to refine the grain structure during ingot casting, and transition element additions (manganese, chromium, and zirconium) that form dispersoid particles (Al20Cu2Mn3, Al18Mg3Cr2, and Al3Zr), which help control the wrought grain structure. Iron and silicon are considered impurities and are held to an absolute minimum, because they form intermetallic compounds (Al7Cu2Fe and Mg2Si) that are detrimental to both fatigue and fracture toughness. Alloy 2024 has been the most widely used of the 2xxx series, although there are now newer alloys with better performance. Alloy 2024 is normally used in the solution-treated, cold worked, and then naturally aged condition (T3 temper). Cold working is achieved at the mill by roller or stretcher rolling, which helps to produce flatness along with 1 to 4% strains. It has a moderate yield strength (448 MPa, or 65 ksi) but good resistance to fatigue crack growth and fairly high fracture toughness. Another common heat treatment for 2024 is the T8 temper (solution treated, cold worked, and artificially aged).

65

66

67

68

69 Aluminium and aluminium alloys
Non-ferrous metals and alloys Aluminium and aluminium alloys Pure Al Al-alloys Powder aluminium Deformable Cast alloys alloys Heat- Non heat Heat Non heat- treatable treatable treatable treatable Partial solubility No solubility Partial solubility No solubility

70 Aluminum Aluminum is the third most abundant element in the earth's crust, behind silicon and oxygen. It is the most abundant metal. Aluminum is strong, lightweight, electrically- and thermally-conductive, and corrosion resistant. These properties can be enhanced through alloying. Its electrical conductivity make it an excellent choice for electrical applications such as wiring and conductors. Its strength-to-weight ratio makes it attractive in structural applications as well as cast aluminum engine components, e.g. blocks, heads, and manifolds. Its high reflectivity of infrared and visible radiation makes it desirable in headlights, light fixtures, and many insulations. It is also used as a paint pigment. High corrosion resistance • Excellent machining properties • Light weight • High thermal/electrical conductivity • High ductility/easily deformable

71

72

73

74

75

76

77 Copper and copper alloys
Non-ferrous metals and alloys Copper and copper alloys Pure Cu Cu-alloys Brasses Bronzes Cupronickels Deformable Cast Deformable Cast alloys alloys alloys alloys

78 COPPER AND ITS ALLOYS Cu and most of its alloys are homogeneous single phases, there are not susceptible to heat treatment and their strength may be altered only by cold working. Melting point of copper – 1083 ͦ C Main properties of copper: High electrical and thermal conductivity Good corrosion resistance, Machinability, strength Ease of fabrication Non magnetic Can be welded, brazed, and soldered Easily finished by plating Electrical conductors- 99.9% Cu and identified as Electrolytic Tough Pitch (ETP) copper or Oxygen Free High Conductivity (OFHC) copper.

79 Copper, Brass, and Bronze
Copper has been used in various applications for centuries. It generally finds applications requiring high thermal and electrical conductivity. For example, the thermal conductivity of copper is almost ten times greater than ordinary steel. Therefore, it finds use as kitchen products, wiring and electrical applications, piping and tubing, and other such uses. Alloys of copper and zinc are termed brasses. Zinc is added to improve the strength and ductility of the alloy. There are many formulas for brasses which include other alloying elements than copper and zinc. Brass is used in decorative metal products, cartridge cases, piping and tubing, and many of the same application as copper. High electrical conductivity • High thermal conductivity • High corrosion resistance • Good ductility and malleability • Reasonable tensile strength

80 Designation system of Cu and Cu-alloys (1)
Non-ferrous metals and alloys Designation system of Cu and Cu-alloys (1) Designation pure Cu – Cu-ETP etc. Cu deformable alloys – CuZn36Pb3 Cu cast alloys – G-CuSn10 (types of casting : GS – sand casting, GM – die casting, GZ – centrifugal casting, GS – cont. casting , GP – pressure die casting) Conditions (properties) based designation after main designation (EN1173) Letters A – elonagtion (ex Cu-OF-A007) B – bending strength (ex CuSn8-B410) D – drawn, without mech. properties G – grain size (ex CuZn37-G020) H – hardness (Brinell or Vickers) (ex CuZn37-H150) M – as manufactured cond. , without mech. properties R – tensile strength (ex CuZn39Pb3-R500) Y – yield strength (ex CuZn30-Y460)

81 Designation system of Cu and Cu-alloys (2)
Non-ferrous metals and alloys Designation system of Cu and Cu-alloys (2) Materials numbers Includes 2-digit marking, followed by three digit designating the material group ( ) C – copper based alloy CB – ingot CC – casting CM – master alloy CR – rafined Cu CS – brazing and welding material CW – wrought CX – non standardized material For example Designation Material No. Deformable copper Cu-0F CW009A Deformable alloys CuZn37 CW508L Cast copper Cu-C CC040A Cast alloys CuSn10-C CC480K

82 Cu-alloys: Estonian* vs Euro coins**
Non-ferrous metals and alloys Cu-alloys: Estonian* vs Euro coins** Alloy: Nordic gold (Cu89Al5Zn5Sn1) Diameter (mm): 19,75 Weight (g): 4,10 Alloy: Cu93Al5Ni2 Diameter (mm): 17,20 Weight (g): 1,87 Alloy: Nordic gold (Cu89Al5Zn5Sn1) Diameter (mm): 22,25 Weight (g): 5,74 Alloy: Cu93Al5Ni2 Diameter (mm): 18,95 Weight (g): 2,27 Alloy: Nordic gold (Cu89Al5Zn5Sn1) Diameter (mm): 24,25 Weight (g): 7,8 Alloy: Cu93Al5Ni2 Diameter (mm): 19,50 Weight (g): 2,99 Alloy: rim - nickelbronze (Cu75Zn20Ni5); center - three layered: cupronickel (Cu75Ni25), nickel, cupronickel Diameter (mm): 23,25 Weight (g): 7,50 Alloy: Cu89Al5Zn5Sn1 Diameter (mm): 23,25 Weight (g): 5,00 Alloy: rim - cupronickel; center - three layered: nickelbronze, nickel, nickelbronze Diameter (mm): 25,75 Weight (g): 8,50

83 Brass Copper and zinc form solid solution up to ~ 39% zinc at
456°C, giving a wide rage of properties. • Sn(tin), Al, Si, Mg, Ni, and Pb(lead) are added elements, called ‘alloy brasses’. • Commercially used brasses can be divided into two important groups: 1) α brasses (hypo-peritectic) with α structure containing upto ~35% Zn. 2) α+β brasses (hyperperitectic) with α+β two phase structure, based on 60:40 ratio of Cu and Zn Phase diagram of Cu-Zn system α phase – FCC structure β phase – BCC structure (disordered) β’ phase – BCC structure (ordered) γ phase – complex structure (brittle)

84

85 COPPER ALLOYS: Brasses – essentially alloys of cu and Zn
COPPER ALLOYS: Brasses – essentially alloys of cu and Zn. Some of the alloys may contain small amounts of Pb, Sn, Al Variations in composition will result in desired color, strength, ductility, machinability, corrosion resistance, or a combination of such properties Best combination of strength Free cutting brass (61.5Cu-35.5Zn-3Pb) Forging brass (60Cu-38Zn-2Pb) Naval Brass – (60Cu-39.25Zn-0.75Sn) Gliding metal (95Cu-5Zn) Red brass (85Cu-15Zn) Low brass (80 Cu-20 Zn)

86 Microstructure of α brasses
(a) Commercial bronze (90%Cu-10%Zn) (b) Cartridge brass (70%Cu-30%Zn) Pure copper

87 Microstructure of α+β brasses
40% Zn addition provides a complex structure of α and β phases. • 60%Cu-40%Zn (Muntz metal) is the most widely used. • β phase makes this alloy heat-treatable.

88 Bronze Bronze is an alloy of copper and any other metal.
As with brasses, there are many formulas for bronzes, depending on the application. Aluminum bronzes, tin bronzes, phosphor bronzes, nickel bronzes, and silicon bronzes are all examples of varying alloys. The principle alloying element determines the nomenclature. Bronzes are used in applications such as bearings, some limited structural applications, decorative uses, and applications which require them not to spark when struck with another metal. This makes them useful in the transport and handling of items such as explosives, fuels, and flammable materials. Bronzes are often used in statues and can be seen to form the familiar green oxidized coating. Bronzes – up to 12 % alloying elements. Alloys of Cu and Sn, Al, Si, Be, in addition may contain P, Pb, Zn, or Ni A. Tin bronzes (Phosphor bronzes) B. Silicon bronzes C. Aluminum bronzes D. Beryllium bronzes

89

90 Magnesium and magnesium alloys
Non-ferrous metals and alloys Magnesium and magnesium alloys Pure Mg Tm – 649 °C Density – 1740 kg/m3 (lightest among the engineering materials) Mg-alloys Mg – Mn (up to 2,5 %) Mg – Al – Zn (up to 10 % Al, 5 % Zn) Heat treatment of Mg-alloys Similar to Al-alloys Quenching + age hardening (NA, AA → MgZn2, Mg4Al3 jt) → Rm ↑ 20 … 30 %

91 Mg-alloys Designation Deformable Mg-alloys Mg cast alloys (EN173)
Non-ferrous metals and alloys Mg-alloys Designation deformable (ex MgMn2) cast alloys (ex designation MCMgAl8 / material No. MC21110) Deformable Mg-alloys Mg cast alloys (EN173) Designation Rm Rp0,2 N/mm2 A % Applications MgMn2 MgAl8Zn 145 15 6 Corrosion resistant, weldable cold formable; conteiners, car , aircraft and machine manufacturing MCMgAl8Zn1 MCMgAl6 MCMgAl4Si 8 4-14 3-12 Good castability. Dynamically loadable. Car and aircraft manufacturing.

92

93

94

95

96

97

98 Titanium and titanium alloys
Non-ferrous metals and alloys Titanium and titanium alloys Pure Ti Tm – 1660 °C Density – 4540 kg/m3 Very active to O, C, N → 2x hardnes increase Ti-alloys, classification Ti – Al – alloys (4…6 % Al) – -alloys Ti – Al – Cr, V, Cu, Mo - alloys –  + -alloys Ti – Al – Mo, Cr, Zr - alloys – -alloys Heat treatment of Tialloys Heating up to -area (850…950 °C) and cooling  martensitic transformation. Ageing (450…600 °C) – max effect by -stabilisators (Cr, Mn, Fe, Ni, Cu, Si) Additional heat treatment – nitriding (750…900 HV)

99 Titanium alloys Rm N/mm2 Rpo,2 Non-ferrous metals and alloys
Designation HB Rm N/mm2 Rpo,2 A % Applications Ti 1…3 30-18 Weldable, machinable and cold formable. Ti1Pd, Ti2 Pd 30-22 Corrosion resistant light constructions. TiAl6V4 310 8 Machine elements in medicine, food, ZnAL11Cu1 (ZP12) 350  1050 1050 9 chemical and aircraft industry. Advantages: highest specific strength good formability Disadvantages: need for a protective atmosphere at HT (Ar) problematically casted (reacting with ladle material, ZrO2 must be used)

100

101

102 Magnesium Magnesium is a light material, lighter than aluminum, derived primarily from seawater. Magnesium is a very active metal and, when burned, gives off an intense heat and light. It is used as an alloying element in steels and in applications which require high strength-to-weight ratios, such as extension ladders, aircraft, space vehicles, power tools, and similar applications. Non-Ferrous

103 Chromium Chromium is often used in decorative and corrosion-resistant coatings. It is a major alloying element in many steels, especially stainless steels. It is used to provide a tough, wear-resistant, corrosion-resistant, decorative surface. Non-Ferrous

104 Nickel Nickel is used as a plating material. It polishes to a high luster. It offers a wide working temperature range. It is also used as an alloying element for other materials, such as steels and bronzes. Nickel is also used in magnets, heating elements, thermocouples, and rechargeable batteries. Nickel and nickel silver are used in jewelry and coins. Non-Ferrous

105 Gold, Silver, Platinum These are generally termed the precious metals due to their cost/value and use in coinage and jewelry. For example, the $20 gold piece at one time contained $20 worth of gold. Today, coins are used to represent the face value and are made from less expensive materials. Gold, silver, and platinum are used as plating materials. They offer good conductivity and corrosion resistance. Gold and silver are too soft to be used in a pure form and are often alloyed with copper, nickel, or platinum to increase their strength. Gold and silver have been used for dental caps, crowns, and fillings. Non-Ferrous

106 Silver Silver also finds application in photographic films and papers. At one time, it was used to plate mirrors. It is now used in the manufacture of photochromatic lenses. Photochromatic lenses darken when exposed to ultraviolet light. Silver is also used in brazing alloys and long-life batteries. Silver fulminate (Ag2C2N2O2) is used as an explosive. Silver and silver compounds are found in many creams, ointments, and salves used for medicinal purposes. Silver iodide has been used to seed clouds to make rain. Non-Ferrous

107 Refractory Metals These metals have melting temperatures above 3600 degrees Fahrenheit (2000 degrees Celsius). Some of these approach 6200 degrees Fahrenheit (3500 degrees Celsius). They include such metals as iridium, osmium, and ruthenium, in addition to, chromium, columbium, hafnium, molybdenum, niobium, rhenium, tantalum, tungsten, and vanadium. They find application where high temperature stability is required. For example, furnace components, high speed tools, temperature-measuring devices and components, aircraft components and space vehicle shields. These metals also find application in electrical devices such as capacitors and rectifiers. Non-Ferrous

108 Titanium Titanium is lightweight and strong. It is an important metal for the aerospace industry which requires high strength under extreme conditions. It is also used in the medical field for instruments and artificial joint replacements. Titanium is also used as a pigment in paints. Non-Ferrous

109 White Metals: Lead, Tin, and Zinc
White metals include antimony, bismuth, cadmium, lead, tin, and zinc. Of these, lead, tin, and zinc are of primary interest. Lead has been used for centuries for plumbing and plumbing-related uses, such as solders, pipe, and fittings. It is easily formed with low heat, corrosion resistant, and ductile. One primary use of lead in the past was as a pigment in lead-based paints. Another prior use for lead was as an octane booster in gasoline as tetraethyl lead. Modern paints and fuels do not contain lead. Lead has been identified as a health hazard and found to be toxic to animals and humans. Lead is used in storage batteries where the battery plates contain high percentages of lead. Due to its high density, it is also used as radiation shielding. Non-Ferrous

110 Tin Tin is a major component of solders and pewter. It is also used as both an alloying element and plating material. Tin is a major alloy of many copper products. It is used to plate other metals due to its corrosion resistance. Non-Ferrous

111 Zinc Zinc is commonly used as a plating material for steels. This product is termed galvanized steel. It is the familiar grayish coating seen on products such as nails and sheets. It is also used in die castings (such as die-cast children's toys, carburetor bodies, and pump housings) and as an alloying element in nonferrous metals. Zinc oxide is used in paints, glass, cements, and medicines. Non-Ferrous

112 Misc. Other Alloys Finally, antimony, bismuth, and cadmium are included in "white" metals. Antimony is used in solders and as an alloying element in nonferrous metals. The same may be said for bismuth which has the lowest thermal conductivity of any metal except mercury. Cadmium is used as a plating material, as a component of rechargeable batteries (Nickel-cadmium batteries), and as a neutron absorber in control rods for nuclear power plants. Zirconium is also used in nuclear reactor structures and fuel shielding due to its low neutron absorption. Non-Ferrous

113 Ferritic stainless steels are principally Fe-Cr-C alloys with 12-14% Cr. They also contain small additions of Mo, V, Nb, and Ni. Austenitic stainless steels usually contain 18% Cr and 8% Ni in addition to other minor alloying elements. Ni stabilizes the austenitic phase assisted by C and N. Other alloying additions include Ti, Nb, Mo (prevent weld decay), Mn and Cu (helps in stabilizing austenite). By alloying additions, for martensitic steels Ms is made to be above the room temperature. These alloys are heat treatable. Major alloying elements are: Cr, Mn and Mo. Ferritic and austenitic steels are hardened and strengthened by cold work because they are not heat treatable. On the other hand martensitic steels are heat treatable. Austenitic steels are most corrosion resistant, and they are produced in large quantities. Austenitic steels are non-magnetic as against ferritic and martensitic steels, which are magnetic.

114

115

116

117

118

119

120


Download ppt "Ferrous Metals."

Similar presentations


Ads by Google