钼基材料的强韧化技术研究现状和发展趋势

钼材料具有导热导电性能好、高强度、高熔点等优点,广泛应用于诸多领域,例如,在核能和航空航天工业中用于制造聚变反应器转向器部件和导弹燃烧室等,在机械工业中用做刀具等零件。但是,当钼材料在高温条件下时,其抗蠕变性能、高温强度以及抗氧化性能都会显著下降,很大程度上影响了材料在诸多领域中的应用。本文主要综述了用不同的方法来提高钼基材料的强韧性,包括合金化、第二相弥散和大塑性变形,介绍了这些方法的机理和对钼材料的改善效果,并对未来钼基材料强韧化研究方向做出了展望。

20Mn2钢晶粒超细化及性能

借鉴超塑预处理细化晶粒的思路 ,在 2 0Mn2钢中加入与其液态 (16 5 0℃ )密度相同、且不溶于钢的ZrC粒子 ,使其成为钢在热轧时的形变核心和奥氏体及形变诱导铁素体的再结晶核心。并综合引入形变强化、相变强化、第二相弥散强化效应及细晶强化效应 ,使两种状态试验钢晶粒尺寸均细化到 1～ 2 μm。与 2 0Mn2钢相比 ,淬火态试验钢σ0 .2 和σb 分别提高 187.0 %和 131.8%。同时 ,延伸率也有所提高 ;油淬态试验钢的σ0 .2 和σb 分别提高为 39.9%和 34.2 % ,与 2 0Mn2钢的塑性指标相比 ,油淬及低温回火态延伸率分别提高了 90 %和 111%。

Effects of shape and size of second phase on mechanical properties of sintered Mo-Y_(2)O_(3) alloys

The morphology and size of second phase greatly influence the strengthening effect on oxidation dispersion strengthened Mo alloys.In this work,a novel nanostructuring strategy is adopted to modify the second phase of Y_(2)O_(3),and the corresponding effects of particle shape and size on mechanical properties of sintered Mo−Y_(2)O_(3) alloys were investigated.It is found that spherical particles with sizes below 200 nm are preferred due to the dominant intragranular distribution of second phases associated with better strengthening effect originating from dislocation pinning.With smaller particle size of Y_(2)O_(3) nanospheres(105 nm),the tensile strength of corresponding Mo alloy is enhanced by about 43.8%,much higher than that(8.3%)reinforced by second phase nanospheres with larger particle size(322 nm).Meanwhile,with similar particle size(around 100 nm),the spherical shape exhibits better strengthening effect than the one reinforced by one-dimensional rod-like second phase.

钼合金的强韧化研究现状及展望

钼及其合金以其诸多优异的性能在各个领域内受到广泛关注,但其抗蠕变性能、高温强度及抗氧化的劣化以及批量化生产手段的不足限制了大规模的工业应用。本文综述了金属钼的脆性来源,指出非本征脆性的改进及制备工艺的革新是钼合金研究和开发的重点方向。介绍了目前钼合金强韧化的主要形式,列举了典型钼合金研究开发现状,总结了钼合金的研究方向。