An Investigation Of Microstructure And Mechanical Properties In Cu-ti-sn Alloys Rich In Copper

摘要

The microstructure and hardness evolution of three alloys based on the system Cu-Ti-Sn, rich in copper, have been investigated (CuTi2 wt.%Sn2.75 wt.%, CuTi3 wt.%Sn2.75 wt.% and CuTi4wt.%Sn2.75wt.%). They are characterised by the presence of the ternary eutectic intermetallic CuTi_3Sn_5 in the as cast state. Suitable thermomechanical treatments cannot dissolve this phase. The effect of a variation in Ti content during ageing was studied by microstructure observations (S.E.M.), chemical analysis (W.D.S.), D.T.A, X.R.D. and hardness testing (Vickers). The low hardness obtained led to consider a chromium addition in CuTi4 wt.%Sn2.7 5wt.%. As for last materials, the microstructure of this alloy is related to its Vickers hardness.