CUTTING TOOLS & FLUIDS

Chan Yim Ling Isaac Koh Ming Kuan Lye Jin Hoon Soon Vern Yee Teo Pao Ter Teoh Kheng Swee Yip Zhang Rong101734

Introduction Cutting Tools Cutting Fluids Conclusion

What is cutting tool/fluid ? General properties ? Types ? STAY TUNED…..

Attached to machine → removal of unwanted part → machining is accomplished Modes of tool failure: a)Fracture – due to excessive force at cutting point b)Temperature – due to cutting temperature too high → tool point soften (plastic deformation) → loss of sharp edge c)Gradual wear – causes loss of tool shape & reduction in cutting efficiency Different cutting tools = Different performances

Hot Hardness Wear resistance Toughness Capability of material to absorb energy before failing High toughness is required Ability of material to retain its hardness at high temperature High hot hardness = high resistance to bulk deformation Ability of material to resist abrasion & erosion High hardness = high wear resistance (required)

Various Types High Speed Steel Plain Carbon Tool Steel Cast Cobalt Alloys Synthetic Diamonds Ceramics Carbides Group

Any liquid that is applied directly to the machining operation to improve cutting performance. Why cutting fluids? – To overcome: a)Heat generation at shear zone and friction zone b)Friction at tool–chip & tool–work

Coolant Role Reduction in temperature Retain tool hardness & reduce thermal distortion

Lubricant Role Reduce friction effect at tool-chip & tool-work Carry away chip

Types Straight Metal Working oil Semi- synthetic metal Working Fluids Emulsifiable Metal Working Oil Synthetic Metal Working Fluids

Discussions of Selected Cutting Tools Comparison of the Tools

Selected Cutting Tool Synthetic Diamond High Speed Steel Cermet, Cemented & Coated Carbides

General Info Strength & Weakness Applications

M- series: Molybdenum (95% of HSS) – Higher abrasion resistance – Less distortion during heat treatment – Inexpensive T- series: Tungsten It was developed to machine at higher speed than carbon steel

STRENGTH High toughness Inexpensive Good for interrupted cuts WEAKNESS Low cutting speeds compare to carbide tools Limited hardenability Limited wear resistance

Drills Reamers Taps Gear Cutters Saw blades

General Info Strength & Weakness Applications

Made of sintered polycrystalline diamond (SPD) Fabricated by sintering fine grained diamond crystal under high temperature and pressure. Crystal have random orientation. SYNTHETIC DIAMOND CUTTING TOOL

STRENGTH Hardest material (6000 HK) High toughness High strength (1000 MPa) WEAKNESS Not suitable for machining ferrous metals and nickel based alloy – Due to chemical affinity between metals & carbon

Widely used in high speed machining of non- ferrous metals and abrasive non-metal materials such as Fiberglass Graphite Wood

General Info Properties Applications

1.Definition Ceramic-metal composites containing TiC, TiN, and certain other ceramics not including WC 2.General Info TiC, TiN, and TiCN, with Ni and/or Mo as binders. Some of the cermets are more complex

3.Properties Higher speeds - better compared with steel-cutting carbide grades. Lower feeds - better surface finishing & no need for grinding. 4.Applications High-speed finishing and semi-finishing of steels, stainless steels, and cast irons.

1.Definition Cermets based on WC–Co, including WC–TiC–TaC–Co 2.General Info Non-steel-cutting grades, consisting of only WC–Co Steel-cutting grades, with combinations of TiC and TaC added to the WC–Co.

3.Properties High compressive strength but low-to-moderate tensile strength; High hardness (90 to 95 HRA); Good hot hardness; Good wear resistance; High thermal conductivity; High modulus of elasticity—E values up to around 600 x 10 3 MPa (90 x 10 6 lb/in 2 ); Toughness is lower than high-speed steel.

Non-steel Cutting Grade Suitable for machining Al, brass, Cu, Mg, titanium, and other nonferrous metals (gray cast iron) Steel cutting Grade Used for low carbon, stainless and other alloy steels 10 to 25wt% of the WC might be replaced by combinations of TiC and TaC 4. Applications

1.Definition Very thin coating to a WC–Co substrate 2.General Info A cemented carbide insert coated with one or more thin layers of wear-resistant material, such as TiC, TiN, and/or Al 2 O 3. Thickness to 13 mm

3.Properties Provides low dynamic force and thermal shock 4.Applications To machine cast irons and steels in turning and milling operations

CharacteristicSynthetic diamondCoated carbidesCemented carbideCermetHSS Toughness Hot hardness Wear resistance Cutting speed Material Sintered polycrystalline diamond WC-Co coated with thin film Cermet + WC-Co Or WC-Co TiC, TiN, TiCNMO (10%) Or T (12-18%) Strength (+) or weakness (-) Can’t use to machine ferrous & Ni alloy (-) Prevent crater wear (+) WC-Co type: Crater wear occur rapidly (-) Can’t cut ferrous alloy (-) Good surface finish (+) Complex single- piece tools possible (+) High rake- angle tools (+)

CharacteristicSynthetic diamondCoated carbidesCemented carbideCermetHSS Exact application of the tools Powder => grinding abrasive Drill bit Incorporated in angle grinder blade. High speed milling Rotary cutters for high-speed cutting of artificial fibres. Blades in boring machine Tool bits Blades in power saw

General Strength Types, Strength & Weakness Parameter of Cutting Fluids

Improve surface finish Increase tool life Improve cutting dimensional accuracy Lower energy consumption Cleaner cutting zone Better corrosion protection

TypesStrengthWeakness Straight metalworking oils Excellent lubrication Good corrosion protection Easy maintenance Poor heat removal Toxic mist High viscosity Flammable Expensive Emulsifiable metalworking oils Good lubrication Good cooling capacity Some corrosion protection Low cost Non-flammable Require other additives (anti-bacteria, maintenance) Toxic mist Susceptibility to form hard water Synthetic metalworking fluids Very good cooling capacity Good lubrication Stable Good corrosion protection Low mist Easy handling, cleaning and maintenance Some toxicity Easy contamination High cost Semi-synthetic metalworking fluids Combination of emulsifiable oils and synthetic fluids

Flow Rate Thermal Practical Directional of Fluid Fluid Pressure Fluid penetration Volume of liquid flow per unit time Chip-tool interface (Rake Face) Work piece-tool interface (Flank Face) Top surface of the chip

Parameters Control Cooling Rate Sticky Zone Hardness of Chip

Improve surface finish Increase tool life Improve cutting dimensional accuracy Lower energy consumption Cleaner cutting zone Better corrosion protection

Cutting tools required high wear resistance, high hardness and high hardness. Cutting fluid applications depend on type of fluid, fluid pressure, fluid flow rate and fluid direction. Combination of cutting tools with cutting fluid will improve the machining process.