Dynamic compaction of titanium aluminides by explosively generated shock waves: Experimental and materials systems

Abstract

Different approaches to compact cylinders of titanium aluminide powders by explosively generated shock waves were explored. Two basic compositions of the titanium aluminide powders produced by the rapid solidification rate (RSR) technique were used: Ti-21 wt pct Nb-14 wt pct Al and Ti-30.9 wt pct Al-14.2 wt pct Nb. A double-tube design utilizing a flyer tube was used in all experiments. Experimental parameters that were varied were initial temperature, explosive quantity, and explosive detonation velocity. The major problem encountered with shock consolidation of titanium aluminides was cracking. Titanium aluminide powders were also mechanically blended with niobium powders in one case and elemental mixtures of aluminum and titanium powders in the other case. Enhanced bonding and decreased cracking were observed in both cases. In the former case, the addition of niobium powder provided a ductile binder medium which assisted in consolidation. In the latter case, due to the additional heat generated and melting produced by the shock-induced reactions between Ti and Al, significant improvements in bonding of the titanium aluminide powders were observed.