MACHINABILITY OF P M MATERIALS AS DETERMINED BY DRILLING TESTS/

The machinability of nearly 1000 ferrous powder metal materials was de termined using an instrumented drilling test. The relative measure of machinability was compared by the number of holes drilled and the axia l drilling force, Material and process variables included composition, carbon content, density, type/amount of machinability additive (such as MnS) and resin impregnation. For conventional powder metallurgy ste els the results confirm resin impregnation as the most beneficial meth od for improving machinability, followed by the addition of 0.5w/oMnS. Certain alloys, such as he austenitic stainless steels, were very dif ficult to machine unless impregnated.