Production Technology (IND 006) Preparatory Year, Faculty of Engineering, Fayoum University Dr. Ahmed Salah Abou Taleb Lecturer, Industrial Engineering Dept., Faculty of Engineering, Fayoum University Lecture No. 3

Introduction

 What are the common characteristics of engineering materials such as physical, chemical, mechanical, thermal, optical, and electrical?  How they can be processed economically to get the desired product?

Materials

Materials Integration

Metals Why metals are considered as the most important materials? They have properties that satisfy a wide variety of design requirements. The metal manufacturing processes have been developed and refined over many years. Engineers understand metals. High stiffness and strength - can be alloyed for high rigidity, strength and hardness. Toughness - capacity to absorb energy. Good electricity and thermal conductivity. Cost.

Metals Pure elementsAlloying Gold Silver Copper is a mixture of two or more elements, at least one of which is metallic through alloying, it is possible to increase strength, hardness, and other properties compared to pure metals.

Phase Diagram

Ferrous Metals Ferrous metals and alloys are defined as the materials that contain a large amount of iron. They are used in the majority of metallic applications in current eng. design,

Ferrous Metals

1. FERROUS MATERIALS AND ALLOYS Steel is an alloy of iron and carbon up to 2.11 % in addition to various elements (or Alloying Elements) in order to improve properties. Steel Ferrous Materials Cast Iron Cast Iron (C.I.) is an alloys of iron, carbon (1.7% %), and silicon (3.5%).

FERROUS MATERIALS AND ALLOYS I- Cast Iron (CI):  Low cost,  Good casting characteristics,  High compressive strength,  High wear resistance and  Excellent machinability,  Tensile strength from 100 to 200 MPa,  Compressive strength from 400 to 1000 MPa and,  Shear strength is 120 MPa.

FERROUS MATERIALS AND ALLOYS Gray Cast Iron Cast Iron Categories Ductile (Nodular)Cast Iron White Cast Iron Malleable Cast Iron I- Cast Iron (CI):

Carbon is free in the form of graphite, which exists in the form of flakes. Good compressive & tensile strength, machinability, and vibration-damping ability Uses: machine bases, crankshafts, furnace doors, Engine Blocks A- Gray Cast Iron: FERROUS MATERIALS AND ALLOYS I- Cast Iron:

Carbon is free in the form of graphite but it takes nodular or spheroid form. High fluidity, excellent castability, strength, high toughness, excellent wear resistance, pressure tightness, weldability and higher machinability Use in gears, cam shaft, crank shaft. B- Ductile (Nodular) Cast Iron: FERROUS MATERIALS AND ALLOYS I- Cast Iron:

Carbon exists in the combined form (Cementite). Very hard; wear resistant, brittle, very difficult to machine, high tensile strength and low compressive strength. Use in bearing surface, rim of car, and Railway brake blocks. C- White Cast Iron: FERROUS MATERIALS AND ALLOYS I- Cast Iron:

It has structure similar to nodular C.I. It has ductility, strength and shock resistance. Use in axle bearing, tracks wheels D- Malleable Cast Iron: FERROUS MATERIALS AND ALLOYS I- Cast Iron:

FERROUS MATERIALS AND ALLOYS Plain Carbon Steel Steel Categories Low Alloy Steel Stainless Steel Tool & Die Steels II- Steel:

A- Plain Carbon Steels: So-called plain-carbon steel contains up to 0.5% manganese, Strength increase and ductility reduced with carbon increase. FERROUS MATERIALS AND ALLOYS II- Steel: AlloyCompositionApplication Low Carbon Steel (Mild Steel) has 0.05% up to 0.20% carbon Automobile sheet metal & railroad rails Medium Carbon Steelhas 0.20% up to 0.50% carbon M/C component & engine parts High Carbon SteelGreater than 0.50% carbon Springs, cutting tool & blades

B- Low Alloy Steels (Constructional Steel): Contains additional alloying elements in amount less than 5% by weight, Mechanical properties superior than plain carbon steel. Higher strength, hardness, wear resistance, and toughness. Used for machine parts highly stressed in tension or compression. FERROUS MATERIALS AND ALLOYS II- Steel:

C- Stainless Steels (Special Steel) (SS): FERROUS MATERIALS AND ALLOYS II- Steel: High alloyed steel design for corrosion resistant. Principle alloying element is chromium (> 15%). Nickel is used to improve corrosion protection. Is more strength and ductile steel. Austenitic stainless ‑ typical composition 18% Cr and 8% Ni Ferritic stainless ‑ about 15% to 20% Cr, low C, and no Ni Martensitic stainless ‑ as much as 18% Cr but no Ni, higher C content than ferritic stainless

FERROUS MATERIALS AND ALLOYS II- Steel: D- Tool & Die Steels : High alloy steel. have great strength, hardness and wear resistance. High strength, hardness, wear resistance, and toughness under impact Used to fabricate cutting tool, moulds and dies.

Effect of carbon content on mechanical properties