IMS ENGINEERING COLLEGE PRESENTATION ON CUTTING FLUID TOOL MATERIAL TOOL WEAR TOOL LIFE PRESENTED BY ADITYA KUMAR 1214340011 ME-1 3rd YEAR IMS ENGINEERING COLLEGE SUBMITTED TO Mr. DEEPAK SHARMA

OBJECTIVE To make you aware about the cutting fluids , tool material , tool wear and tool life in simple and easier way.

OVERVIEW Cutting Fluid Types of cutting fluid Cutting Fluid Effects Cutting Fluid Selection Criteria Tool Material Tool Wear Tool Life

Cutting Fluids Cutting fluids are used in metal machining for a variety of reasons such as improving tool life, reducing work piece thermal deformation, improving surface finish and flushing away chips from the cutting zone. Practically all cutting fluids presently in use fall into one of four categories: 1.Straight oils 2.Soluble oils 3.Semi synthetic fluids 4.Synthetic fluids

Straight oils are non emulsifiable and are used in machining operations in an undiluted form. They are composed of a base mineral or petroleum oil and often contains polar lubricants such as fats, vegetable oils and esters as well as extreme pressure additives such as Chlorine, Sulphur and Phosphorus. Straight oils provide the best lubrication and the poorest cooling characteristics among cutting fluids.  Synthetic Fluids contain no petroleum or mineral oil base and instead are formulated from alkaline inorganic and organic compounds along with additives for corrosion inhibition. They are generally used in a diluted form (usual concentration = 3 to 10%). Synthetic fluids often provide the best cooling performance among all cutting fluids.  Soluble Oil Fluids form an emulsion when mixed with water. The concentrate consists of a base mineral oil and emulsifiers to help produce a stable emulsion. They are used in a diluted form (usual concentration = 3 to 10%) and provide good lubrication and heat transfer performance. They are widely used in industry and are the least expensive among all cutting fluids. 

Semi-synthetic fluids are essentially combination of synthetic and soluble oil fluids and have characteristics common to both types. The cost and heat transfer performance of semi-synthetic fluids lie between those of synthetic and soluble oil fluids. 

Cutting fluid effects The primary functions of cutting fluids in machining are : Lubricating the cutting process primarily at low cutting speeds Cooling the work piece primarily at high cutting speeds Flushing chips away from the cutting zone Corrosion protection of the machined surface Enabling part handling by cooling the hot surface Longer Tool Life Reduced Thermal Deformation of Work piece Better Surface Finish (in some applications) Ease of Chip handling 

Cutting Fluid Selection Criteria Process performance : Heat transfer performance Lubrication performance Chip flushing Fluid carry-off in chips Corrosion inhibition Fluid stability (for emulsions) Cost Performance Environmental Performance Health Hazard Performance

Material Milling Drilling Tapping Turning Aluminium Soluble oil (96% water) or mineral oil Soluble oil (70-90% water) 25% sulfur-based oil mixed with mineral oil Mineral oil with 10% fat (or) soluble oil Brass Soluble oil (96% water) Soluble oil 10-20% lard oil with mineral oil Mineral oil with 10% fat Bronze 30% lard with mineral oil Alloy Steels 10% lard oil with 90% mineral oil 30% lard oil with 70% mineral oil 25% sulfur base oil with 75% mineral oil Cast Iron Dry Dry or 25% lard oil with 80% mineral oil Malleable Iron Copper Low Carbon and Tool Steels 25-40% lard oil with mineral oil 25% lard oil with 75% mineral oil

TOOL MATERIAL Tool failure modes identify the important properties that a tool material should possess: Toughness ‑ to avoid fracture failure Hot hardness ‑ ability to retain hardness at high temperatures Wear resistance ‑ hardness is the most important property to resist abrasive wear

Plain carbon steel shows a rapid loss of hardness as temperature increases. High speed steel is substantially better, while cemented carbides and ceramics are significantly harder at elevated temperatures.

HIGH SPEED STEEL Highly alloyed tool steel capable of maintaining hardness at elevated temperatures better than high carbon and low alloy steels One of the most important cutting tool materials Especially suited to applications involving complicated tool geometries, such as drills, taps, milling cutters, and broaches Two basic types (AISI) Tungsten‑ type, designated T‑ grades Molybdenum‑ type, designated M‑ grades

HIGH SPEED STEEL COMPOSITION Typical alloying ingredients: Tungsten and/or Molybdenum Chromium and Vanadium Carbon, of course Cobalt in some grades Typical composition: Grade T1: 18% W, 4% Cr, 1% V, and 0.9% C

CERAMICS Primarily fine‑grained Al2O3, pressed and sintered at high pressures and temperatures into insert form with no binder. Applications: high speed turning of cast iron and steel Not recommended for heavy interrupted cuts (e.g. rough milling) due to low toughness Al2O3 also widely used as an abrasive in grinding .

SYNTHETIC DIAMOND Sintered polycrystalline diamond (SPD) - fabricated by sintering very fine‑grained diamond crystals under high temperatures and pressures into desired shape with little or no binder Usually applied as coating (0.5 mm thick) on WC-Co insert Applications: high speed machining of nonferrous metals and abrasive nonmetals such as fiberglass, graphite, and wood Not for steel cutting

CUBIC BORON NITRIDE Next to diamond, cubic boron nitride (cBN) is hardest material known Fabrication into cutting tool inserts same as SPD: coatings on WC‑Co inserts Even at high temp. C.B.N is chemically inert to ferrous metals and resist oxidation. Applications: machining steel and nickel‑based alloys SPD and cBN tools are expensive

TOOL WEAR Abrasion - dominant cause of flank wear Adhesion – high pressure localized fusion and rupturing Diffusion – Loss of hardening atoms at tool-chip boundary (contributes to crater wear) Plastic deformation – contributes to flank wear

CRATER WEAR FLANK WEAR

Taylor Tool Life Equation This relationship is credited to F. W. Taylor (~1900) where v = cutting speed; T = tool life; and n and C are parameters that depend on feed, depth of cut, work material, tooling material, and the tool life criterion used n is the slope of the plot C is the intercept on the speed axis

A more general form of the equation is

THANK YOU