Table of contents Chipping Machining - 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

Classification of chipping machining Main group 3 Cutting operations With geometrically defined cutting edges Turning Milling Drilling Shaping Broaching With geometrically undefined cutting edges Lapping Grinding Honing Classification of chipping machining

g b a a ... clearance angle b ... wedge angle a + b + g = 90° chip workpiece a Cutting tool wedge a ... clearance angle b ... wedge angle a + b + g = 90° g ... rake angle The Cutting Edge

How to choose a proper clearance angle a ... clearance angle a small: 4° to 5° a: 5° to 8° a big: 8° to 10° Used for high alloyed steel hardened steel short chipping materials Standard for steel and casting alloys Used for aluminium, copper clastics long chipping materials How to choose a proper clearance angle

How to choose a proper rake angle g ... rake angle - + + g high positive 15° to 30° g positive 5° to 15° g negative -5° to -25° Little cutting force needed easy chip removal Used for aluminium, copper, plastics Standard for steel and casting alloys much cutting force needed great chip bending Used for high alloyed steel, hardened steel How to choose a proper rake angle

How to choose a proper wedge angle Depends on a and 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

Cutting-tool materials Properties - Hardness: Sufficient hardness to resist wear and give an adequate life - Bending stability and ductility: To avoid insert breakage - 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

Cutting-tool materials poly crystalline boron nitride (PKB), cubic boring nitride (CBN) Ideal cutting-tool material diamond Cemented carbide (hard metal) ceramics coated Wear resistance high-speed steels (HSS) coated uncoated uncoated high-carbon steels Toughness Cutting-tool materials

Vocabulary chipping machining Spanende Fertigung cutting edge Schneide cutting tool wedge Schneidkeil turning, to turn Drehen, drehen milling,to mill Fräsen, fräsen drilling,to drill Bohren, bohren shaping, to shape Stoßen, stoßen broaching, to broach Räumen, räumen grinding, to grind-ground-ground Schleifen, schleifen honing, to hone Honen, honen lapping, to lap Läppen, läppen rake angle Spanwinkel clearance angle Freiwinkel wedge angle Keilwinkel chip Span alloyed steel legierter Stahl hardened steel gehärteter Stahl roughing, to rough Schruppen, schruppen finishing, to finish Schlichten, schlichten casting alloys Gusswerkstoffe hot hardness Warmhärte wear resistance Verschleißfestigkeit compression strength Druckfestigkeit toughness Zähigkeit bending strength Biegefestigkeit service life Standzeit wear Verschleiß edge chipping Ausbröckeln der Schneide cratering Kolkverschleiß insert breakage Plattenbruch fracture, crack Riss tool point Werkzeugspitze coated beschichtet tungsten Wolfram cemented carbide, hard metal Hartmetall poly crystalline boron nitride polykristallines Bornitrid Vocabulary