Effect of ball powder ratio on microstructure and compressive behaviour of porous Ti-4wt %Al alloy

Abstract

Ti and Al powders were milled in the weight proportion 24:1 using horizontal planetary ball mill. The ratio of ball to powder amounts (BPR) was varied (10, 15, and 20) in the milling process. Powder mixture milled with different BPRs were characterized by the XRD and FESEM to probe the evolution of phase and particles shape and size. Further, these mixtures were used to make porous cylindrical samples through space holder method. The used space holder amount was 60 v%. Compression test of the samples were performed on Universal Testing Machine. It was analysed that crystallite size, shape and size of the powder particles considerably affected by the used ball to powder ratio.XRD confirms that phase formation is invariant with the BPR. The observed relative density is about 10% higher than the used space holder content. Porous sample synthesized by the powder milled with 15 BPR has higher plastic collapse stress and energy absorption capacity as compared to the samples made of the powder milled with 10 and 20 BPRs.