Mo元素含量对TiAl合金微观组织及力学性能的影响

Effect of Mo Element on Microstructure and Mechanical Properties of TiAl Alloys

设计了4种不同Mo含量的Ti Al合金,使用扫描电子显微镜、纳米压痕、热模拟压缩等手段对Mo-TiAl合金的微观组织以及力学性能进行了研究。结果显示,随着Mo含量升高,组织中γ相含量逐渐减少,而β相含量逐渐增多。Mo元素主要以β相的形式存在于TiAl合金中。在热等静压过程中,Mo元素从γ相和α相向β相中扩散;Mo-TiAl合金的纳米压痕硬度在Mo含量为1.59%(原子分数,下同)时达到最大,并且纳米压痕硬度和片层间距呈负相关;随着Mo含量升高,Mo-TiAl合金热压缩流变应力降低,Mo含量为2.11%和3.94%的TiAl合金由于Al元素偏析导致其塑性较差。

Four Ti Al alloys with different Mo contents were designed, and the microstructure and mechanical properties of these MoTi Al alloys were studied by scanning electron microscope, nanoindentation, and hot compression simulation methods. Results show that with increasing the Mo content, the content of γ phase is gradually decreased, while that of β phase is gradually increased. The Mo element mainly exists in the form of β phase in the Ti Al alloy. During the hot isostatic pressing process, the Mo element is diffused from the γ and αphases to the β phase. The nanoindentation hardness of Mo-Ti Al alloy reaches the maximum when the Mo content is 1.59at%, and it is negatively correlated with the interlamellar space. As the content of Mo element increases, the flow stress of Mo-Ti Al alloys decreases, and the Ti Al alloys with 2.11at% and 3.94at% Mo addtion have poor plasticity due to the Al element segregation.