Nb掺杂对Ti-Al合金化层抗高温氧化性能的影响

发布时间：2018-04-25 11:34

  本文选题：钛合金 + Ti-Al合金化层　； 参考：《材料工程》2017年02期

【摘要】：为提高钛合金TC4的抗高温氧化性能,采用激光表面合金化技术在钛合金表面制备不同Nb掺杂量的Ti-Al合金化层。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)、箱式电阻炉等对合金化层的组织结构和高温氧化行为进行分析测试。结果表明,合金化层主要组成物相为TiAl以及少量的Ti_3Al相。Nb主要以置换溶质原子的形式固溶于合金化层中。合金化层组织均匀,与基体呈典型的冶金结合,在不含Nb的Ti-Al合金化层中发现大量的表层裂纹及少量的贯穿性裂纹,而在Nb掺杂的合金化层中未发现明显的宏观裂纹。合金化层在800℃保温1000h的氧化增重显著低于基体,表现出优异的抗高温氧化性能。相比而言,随着Al含量和Nb掺杂量的提高,合金化层的抗高温氧化能力也随之提高。Nb掺杂提高Ti-Al合金化层抗高温氧化性能的作用机理包括减少TiO_2中的空位缺陷、细化氧化物颗粒及促进Al_2O_3的形成。
[Abstract]:In order to improve the oxidation resistance of titanium alloy TC4 at high temperature, different NB doped Ti-Al alloying layers were prepared on the surface of titanium alloy by laser surface alloying technique. The microstructure and high temperature oxidation behavior of alloying layer were analyzed and measured by X-ray diffractometer, scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and box resistance furnace. The results show that the main composition of alloying layer is TiAl and a small amount of Ti_3Al phase. NB is mainly dissolved in the alloying layer in the form of substitution solute atoms. The microstructure of alloying layer is uniform, and it has typical metallurgical bonding with the matrix. A large number of surface cracks and a few penetrating cracks are found in the Ti-Al alloying layer without NB, but no obvious macroscopic cracks are found in the NB doped alloying layer. The oxidation weight gain of the alloying layer at 800 鈩，

本文编号：1801136