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Table of contents. - Classification of chipping machining. - The cutting edge. - How to choose proper cutting angles. - Properties of cutting-tool materials. - Survey of cutting-tool materials. Chipping Machining. Main group 3 Cutting operations. With geometrically defined cutting edges.
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Table of contents - Classification of chipping machining - The cutting edge - How to choose proper cutting angles - Properties of cutting-tool materials - Survey of cutting-tool materials Chipping Machining
Main group 3 Cutting operations With geometrically defined cutting edges Broaching Turning Shaping Milling Drilling With geometrically undefined cutting edges Lapping Honing Grinding Classification of chipping machining
g b chip workpiece a Cutting tool wedge a ... clearance angle b ... wedge angle a + b + g = 90° g ... rake angle The Cutting Edge
a ... clearance angle a small: 4° to 5° a: 5° to 8° a big: 8° to 10° Standard for steel and casting alloys • Used for • aluminium, copper • clastics • long chipping materials • Used for • high alloyed steel • hardened steel • short chipping materials How to choose a proper clearance angle
- + + g ... rake angle g high positive 15° to 30° g positive 5° to 15° g negative -5° to -25° much cutting force needed great chip bending Used for high alloyed steel, hardened steel Little cutting force needed easy chip removal Used for aluminium, copper, plastics Standard for steel and casting alloys How to choose a proper rake angle
... wedge angle Depends on aand g b big b small strong cutting edge Used for high alloyed steel, hardened steel rough machining weak cutting edge Used for Aluminium, Plastics finishing operations How to choose a proper wedge angle
Properties - Bending stability and ductility: To avoid insert breakage - Hardness: Sufficient hardness to resist wear and give an adequate life - Resistance to temperature changes: To avoid insert fracture and breakage - Hot hardness: The ability to retain its hardness at high temperatures generated at the tool point when cutting - Compression strength: To avoid deformation and edge chipping - Oxidation and diffusion resistance: To avoid build up edges and cratering Wear resistance Toughness Cutting-tool materials
poly crystalline boron nitride (PKB), cubic boring nitride (CBN) Ideal cutting-tool material diamond Cemented carbide (hard metal) coated ceramics high-speed steels (HSS) Wear resistance coated uncoated uncoated high-carbon steels Toughness Cutting-tool materials