WORK HARDENING IN TURNING OF AL-10%WT CU ALLOY PRODUCED BY RHEOCASTING

Document Type : Original Article

Authors

1 Mechanical Engineering Department, Al Azhar University, Cairo.

2 Mechanical Design and Production Engineering Department, Ain Shams University, Cairo.

Abstract

The present paper gives some results on the work hardening obtained during turning of A1-10% Cu alloy produced by rheocasting and conven-tional casting techniques. The machinability of this alloy is shortly discussed. A simple procedure was adopted to turn cylindrical workpieces on a centre lathe to investigate the effect of the feed and the depth of cut on the work hardening of such an alloy. Microhardness was measured across specimens, thus determining the depth of the work hardened zone in the vicinty of the periphery. Results show that the depth of the work hardened layer in the rheocast specimens was less than that of the con-ventionally cast specimens indicating better machinability of the former. This behaviour is related to the microstructure formed by each casting technique. The relatively hard spheres of primary phase embedded in a highly fine two phase harder matrix present in the rheocast specimens is thought to be responsible for the smaller depth of the work hardened zone.