论文部分内容阅读
实验研究了变形态Mo-La合金丝的显微组织和力学性能对La含量的敏感性。实验结果表明,随着La含量的增加,变形态Mo-La合金丝的显微组织和力学性能的变化不大。这与退火态钼合金丝的强韧化效果随La含量变化而变化的规律不同。这一现象是La元素在钼合金丝中的赋存形式及其转化过程的时序性特征所致。Mo-La合金丝中,晶粒细化和位错钉扎的效果取决于La2O3颗粒的数量及其在钼基体中的弥散度。XRD衍射谱表明,在固-液掺杂MoO2还原制得的Mo-La合金粉末中,La元素并不是以La2O3,而是以La2Mo2O7的形式存在。La2O3颗粒是在Mo-La丝的整个工艺过程中,通过La3+离子与游离态氧原子结合,或La2Mo2O7分解的途径而逐步形成的。变形态Mo-La合金丝的制备过程不足以使La3+离子全部转变为La2O3,导致La2O3颗粒的生成过程滞后于制备过程,因此La含量对Mo-La合金丝的力学性能和显微组织的影响趋势不甚明显。
The microstructure and mechanical properties of the modified Mo-La alloy wire were experimentally investigated for their sensitivity to La content. The experimental results show that the microstructure and mechanical properties of the deformed Mo-La alloy wire have little change with the increase of La content. The results show that the regularity of the strengthening and toughening effect of annealed molybdenum alloy wire varies with the La content. This phenomenon is due to La element in the molybdenum alloy wire in the form of occurrence and the timing of the transformation process. Mo-La alloy wire, grain refinement and dislocation pinning effect depends on the number of La2O3 particles and their dispersion in the molybdenum matrix. The XRD patterns show that the La element is not La2O3 but La2Mo2O7 in the Mo-La alloy powder prepared by solid-liquid doping with MoO2. La2O3 particles gradually formed during the whole process of Mo-La wire through the combination of La3 + ions and free oxygen atoms or the decomposition of La2Mo2O7. The preparation process of Mo-La alloy wire is not enough to make all the La3 + ions convert to La2O3, which leads to the lagging of La2O3 particles in the preparation process. Therefore, the influence of La content on the mechanical properties and microstructure of Mo- Not obvious.