Machine and Machinability
By David Shea
Many parts are machined to achieve close tolerances or controlled surface finishes. Machining operations are expensive because they require precise capital equipment and trained labor. For some materials, the cost of metal cutting tooling can exceed the material cost. Therefore machining properties of materials must be considered in a competitive environment because they drive a substantial component of cost.
In this talk, the relationship between material properties and a variety of machining characteristics of materials was explored. Topics covered included deformation conditions in machining as well as the effect of material strength, ductility, and microstructure on machining costs. He also discussed the issues and difficulty in trying to extrapolate from the conditions of a controlled material test to machining conditions. Particular attention was on aluminum alloys and the relative significance of chips and burrs versus tool wear for ductile alloys.