原位合金化双丝电弧增材制造γ-TiAl组织性能研究

Microstructure and properties of γ-TiAl fabricated by in-situ alloying assisted double-wire arc additive manufacturing

摘要:

本文采用双丝电弧增材制造的方法制备了Ti-48Al合金，在此基础上通过原位合金化制备了Ti-48Al-2Cr-2Nb金属间化合物，借助XRD，OM，SEM，微小力学拉伸以及高温氧化试验表征了两种合金的组织与性能。研究结果表明，两种堆积试样的成分均匀，并且均由γ-TiAl和α2-Ti3Al片层组织组成，微量合金元素Cr和Nb的添加不改变合金的相组成。微小力学拉伸结果证实了Cr和Nb微量元素的添加可以显著提高合金的抗拉强度，但对塑性没有明显的影响。高温抗氧化性试验结果表明，Ti-48Al-2Cr-2Nb合金试样比Ti-48Al合金具有更优良的抗氧化性能，试样的最终增重由5.26 g/cm2降低至1.95 g/cm2。

Abstract:

Ti-48Al and Ti-48Al-2Cr-2Nb alloys were fabricated by in-situ alloying assisted double-wire arc additive manufacturing. The microstructure and properties of the two alloys were characterized by XRD, OM, SEM, micro mechanical tensile test and high temperature oxidation test. The results showed that both of these two deposited alloys showed quite uniform components and composed of γ-TiAl and α2-Ti3Al. The addition of tracing Cr and Nb showed no significant effect on microstructure. Micro tensile testing showed that ultimate strength elevated after the addition of Cr and Nb yet no significant effect to plasticity. High temperature oxidation resistance test confirmed that Ti-48Al-2Cr-2Nb has a good resistance to oxidation compared to Ti-48Al. The final weight gain of the sample decreased from 5.26mg /cm2 to 1.95mg /cm2.