Machining Manufacturing Processes © 2012 Su-Jin Kim GNU Cutting Tool Materials ( 공구 재질 ) HSS ( 하이스 ) Carbide ( 초경 ) Cermet CBN Diamond

Machining Manufacturing Processes © 2012 Su-Jin Kim GNU Cutting-Tool Materials A cutting tool has the following characteristics: 1.Hardness ( 경도 ) at high temperature ~ Speed 2.Toughness ( 인성 ) ~ Feed & depth 3.Wear resistance ( 내마모성 ) 4.Chemical stability ( 화학적 안정성 )

Machining Manufacturing Processes © 2012 Su-Jin Kim GNU HSS ( 하이스 ) HSS (High-speed steels) HSS cuts faster than carbon tool steel, hence the name high speed steel, but slower than carbide tools. It is often used in power saw blades and drill bits. TiN-Coated HSS PVD (physical vapor deposition), TiN coating reduces tool wear. HSS Drill:

Machining Manufacturing Processes © 2012 Su-Jin Kim GNU Carbides ( 초경 ) Carbides Better wear resistance, stiffness, hot hardness Tungsten carbide: WC + Co(for toughness)  powder metallurgy (sintered), suitable for non-ferrous, grey cast iron Titanium carbide: TiC + Co : TiC is suitable for steel and cast iron Coated Carbide Carbide + TiC, TiN, Al 2 O 3 coated by CVD (chemical vapor deposition) Chemically stable  greatly reduce crater wear

Machining Manufacturing Processes © 2012 Su-Jin Kim GNU Cermets Ceramics Aluminum oxide(Al 2 O 3 ), Silicon-nitride(SiN), cold pressed and hot sintered Hot hardness ↑, toughness ↓ (chipping), thermal shock Cermets Ceramic(Al 2 O 3 ) + metal binder(TiC) Hot hardness ↑, toughness ↓, thermal expansion ↑ Insert: less thermal stress, eliminate grinding by user, less setting time

Machining Manufacturing Processes © 2012 Su-Jin Kim GNU Diamond, CBN Diamond (Poly crystal diamond) Hardest material, Not good for steel CBN (polycrystalline cubic boron nitride) 2nd hardest material, brittle, expensive

Machining Manufacturing Processes © 2012 Su-Jin Kim GNU Tool materials Tool materials, feeds, and cutting speeds Characteristics of cutting-tool materials gives a range of cutting speeds and feeds for different applications. Coated HSS / HSS Feed (Toughness) Speed (Hardness) Coated carbide Carbide Cermet Cera mic PCD CBN

Machining Manufacturing Processes © 2012 Su-Jin Kim GNU Workpiece materials ( 소재 재질 ) Workpiece materials and cutting speeds when Carbide tool or coated carbide tools is used for turning MaterialCutting speed (m/min) Aluminum alloys Copper alloys Cast iron, gray Steels Titanium alloys10-100

Machining Manufacturing Processes © 2012 Su-Jin Kim GNU Cutting Tool Makers ( 공구 제작사 )

Machining Manufacturing Processes © 2012 Su-Jin Kim GNU Cutting Fluids ( 절삭유 ) Also called lubricants and coolants, cutting fluids. Used extensively in machining operations to: 1.Cool the cutting zone 2.Reduce friction and wear 3.Reduce forces and energy consumption 4.Wash away chips 5.Protect surfaces from any environmental attack

Machining Manufacturing Processes © 2012 Su-Jin Kim GNU Sawing and saws ( 톱 ) A cutting operation where the tool consists of a series of small teeth that removes material. Belt sawDisk saw