Ti14合金半固态变形后热稳定性的研究

Research on Thermal Stability of Ti14 Alloy after Semi-Solid Deformation

摘要:

以新型阻燃钛合金Ti14(α+Ti2Cu)为对象，对比研究常规和半固态加工后合金的热稳定性。结果表明：热暴露时间不超过150 h时，半固态加工试样的强度明显优于常规加工试样，且塑性相差不大。而热暴露200 h后两种状态加工的合金热稳定性相近。常规加工态，Ti2Cu相以颗粒状弥散分布于晶内；半固态加工，Ti2Cu相熔化并在冷却过程中以条状偏析于晶界，使得断口韧窝粗化并出现少量解理条纹，这是导致合金热稳定性能改变的重要因素

Abstract:

The thermal stability of Ti14, a new typical α+Ti2Cu burn resistant alloy, after conventional forging and semi-solid forging (SSF) were investigated. The results revealed that under the condition of thermal exposure time no more than 150 h, Ti14 alloy after SSF had higher tensile strength than that of conventional one and the plasticity of the two forging state was similar. Up to 200 h, these two states alloy had similar thermal stability. The Ti2Cu particles distributed in grains uniformly after conventional forging; While in the process of SSF, Ti2Cu phases melted and precipitated on the grain boundaries as banding precipitations during cooling, which formed coarse dimples and few cleavages in microfracture, leading to the change of thermal stability