Experimental Study on the Effect of Cadmium on Delayed Aging of A356 alloy

Abstract

This work was carried out to study the effect of addition of Cadmium on delayed aging of A356 alloyby performingsolutionizing and artificial aging. The base alloy was casted in the form of DTD bars by mould casting. Care is taken to maintain uniform chemical composition in both the alloys. In this work  the precipitation hardenable 7%Si,0.3%Mg  cast alloy was consider for the investigation, i.e., A356 alloy and A356+Cd alloy. The alloy with cadmium was prepared by adding 0.17% of cadmium to the base A356 alloy. The test specimens were prepared by EDM process, in order to keep the specimen morphology intact, which also which minimize the formation of heat affected zone in the samples.  The composition of magnesium and silicon may plays an important role in coarse precipitation of the alloy. The time elapsed between quenching and artificial aging during precipitation hardening is a deteriorate phenomenon where mechanical properties decreases after solutionizing and artificial aging. From the experimental study it is found that the trace additions of cadmium arrest delayed aging at room temperature, it may be due to high solute vacancy binding energy with excess vacancies after solutionizing.

Key words-Cadmium, A356 alloy,Delayed aging, Solutionizin, Artificial aging.