Strain hardening analysis and modelling for sintered Al-Cu-TiC preforms with varying process parameters during cold upsetting

In sintered preforms, the presence of porosities are unavoidable; however, subjected to further deformation, preforms not only show closure of pores but as well as hardens the matrix. Both these phenomenon compliments each other in strain hardening effect, eventually its mechanical characteristics. However, in addition to the deformation, the process parameters also play a prominent role in influencing the strain hardening behaviour. Thus, while it is imperative to establish strain-hardening characteristics for the chosen composition under various process parameter influence, the modelling of the same is also inevitable to design preform for the desired characteristics. In the present investigation, Al with 4.5%Cu preforms has been synthesised through powder metallurgy process, in which, the process parameters such as, weight percentage of TiC, aspect ratio, initial density and the lubricant are varied to two different levels. The complete experiment has been formulated using 24 factorial design; however, it is performed in random order. The study is focused on evaluating strain-hardening characteristics of chosen composition under the influence of process parameters. In addition, the process parameters are modelled using Yates algorithm, and the applicability of the model is ensured through regression analysis and model adequacy test.