热压烧结温度对固相再生TC4钛合金微观组织及硬度影响

通过热压烧结法对TC4钛合金废屑进行固相再生,并对固相再生TC4钛合金的微观组织和硬度进行了分析测试,研究了热压烧结温度对固相再生TC4钛合金微观组织和硬度的影响。结果表明,在给定的热压烧结工艺条件下,TC4废屑结合良好,且没有产生新的亚稳相,再生坯料的相组成与母材一致,仍为典型的α+β组织。烧结温度升高,会使再生合金微观组织中的β-Ti晶粒长大,晶界模糊并导致部分针状的α-Ti以团束的形式析出,显微组织中的β-Ti相含量提高,针状的α-Ti组织则明显减少,烧结温度为1 200℃时,合金组织由网篮组织转变为魏氏组织。再生合金的显微硬度值也随着烧结温度的升高而提高。

Effects of Hot-pressed Sintering Temperature on Microstructure and Micro-hardness of Solid State Recycled TC4 Titanium Alloy

The solid state recycled process of TC4 titanium alloy chips was performed by hot pressing sintering method, and the microstructure and hardness tests of the recycled TC4 titanium alloy was analyzed to understand effects of hot pressing sintering temperature. The results reveal that under the given condition of hot pressing sintering process, the chips of TC4 alloy present a satisfied bonding with absence of any new phase, and the phase composition of recycled billet is consistent with the parent metal, which is still a typical α+β type structure. With the increase of sintering temperature, the growth of β-Ti grains in the microstructure of the recycled TC4 alloy can be observed with the blurring of grain boundary and the precipitation of some acicular α-Ti in form of clusters. The proportion of beta Ti phase in the microstructure will be increased, while the acicular α-Ti structure will be decreased significantly. When the sintering temperature is 1 200 ℃, the microstructure of the alloy is changed from basket weave structure into Widmanstatten structure. The micro-hardness of recycled TC4 alloy is increased with the increase of the sintering temperature.