Manufacturing Processes Fundamentals of Cutting South Bend lathe Chip Formation Chip Breakers Feeds and Speeds Tool Materials Tool Properties Tool Wear Surface Finishes Cutting Fluids CNC Lathes

Manufacturing Processes South Bend Engine Lathe

Manufacturing Processes Chip Formation Discontinuous Continuous Built up edge

Manufacturing Processes Chip Breakers On the Cutting Tool In the Material –Inclusions –Sulfur

Manufacturing Processes Speed, Feed, Depth of Cut

Manufacturing Processes Speeds, Depth of Cut Depth of Cut Speed

Manufacturing Processes Feed Rates or

Manufacturing Processes Cutting Time Considerations Material removal rate Time to Cut

Manufacturing Processes Tool Materials High Speed Steel (HSS) Coated Carbide Inserts

Manufacturing Processes Tool Properties High Hardness Resist Abrasion Resist Chipping Hot Hardness Resist Bulk Deformation (E) Chemical Stability Adequate Thermal properties Consistent Tool Life Geometry

Manufacturing Processes Tool Wear slow death mechanisms: gradual wear on flanks, or rake face of tool (crater) –abrasion, adhesion, diffusion, chemical sudden death mechanisms: unpredictable, catastrophic failure –brittle fracture, chipping, plastic deformation

Manufacturing Processes Tool Life Taylor's Equation: Surface Speed Variation in material hardness –within piece and piece to piece Variation in tool material and geometry Vibrations Changing surface characteristics of workpiece

Manufacturing Processes Tool Geometry

Manufacturing Processes Surface Finishes Tool Geometry and Feed rate

Manufacturing Processes Surface Finishes Surface Speed and Depth of Cut

Manufacturing Processes Cutting Fluids Reduces Cutting Temperature –dimensional stability –reduces thermal tool wear Acts as Lubricant –reduces forces and energy consumption

Manufacturing Processes Cutting Fluids Flood Cooling –lowers temperature –reduces oxidation Mist Cooling –Better Visibility –gets to inaccessible areas

Manufacturing Processes Effects of Coolants On workpiece –cracking, staining, chemical attack On machines –bearings and slideways On environment –breathing apparatus, and disposal