Friction welding of conventional Ti-6Al-4V alloy with a Ti-6Al-4V based metal matrix composite reinforced by TiC

摘要

Titanium alloys are supreme structural materials primarily due to their high specific strength. However, their wide use is largely restrained by the high cost of raw titanium compared to other metals commonly used in structural alloys. Layered structures of titanium alloys allow substantial increase of the material utilisation ratio and therefore draw significant attention. The rational ways of layered parts fabrication are bonding or joining of individually optimised layers into a final complex structure. The use of friction welding to join the parts is one of the most attractive ways of achieving a desirable result, since it is a solid state and near-net-shape process that modifies the structure of connected parts only locally. The study goal was to validate feasibility of the layered structures of Ti-6Al-4V (Ti-64) alloy and metal matrix composite (MMC) on its base with 10% of TiC fabricated by rotary friction welding (RFW) and linear friction welding (LFW). Both initial structures, Ti-64 and MMC, were made using low-cost blended elemental powder metallurgy. RFW and LFW were successfully used to bond the sections of the alloy and its composite. TiC particles stabilise the structure and are not fragmented by friction welding under used processing parameters.