相图分析在二元钼合金中的应用

APPLICATION OF PHASE DIAGRAM IN THE BINARY ALLOYING PROCESS OF MOLYBDENUM

本文通过二元相图,分析了几种常见元素在钼合金化过程的存在方式,阐述了Fe、Cr、W、Ti和Zr的强化机理,系统地论述了各元素在钼合金的不同工作温度所起的作用。分析表明,在0. 4～0. 7 T熔点温度范围,固溶在钼基体中的Ti、Zr、Fe等元素通过晶格畸变阻碍位错交叉滑移和弥散分布的氧化物第二相通过钉扎亚晶界、晶界,抑制再结晶形核所需的大角晶界的形成,占据再结晶形核位置实现组织强化;在0. 7 T熔点温度以上,主要以提高金属晶格中原子间键合力,进而提高自扩散激活能,获得超高温工作强度,W元素在该途径具有优势。本文利用相图指导钼的合金化方向,且对不同工作温度的钼制品添加元素种类和含量进行精细化配制,可将钼合金根据强化效果应用于不同领域。

The ways of existence and strengthening mechanisms of common elements of Fe、Cr、W、Ti and Zr in the alloying process of molybdenum were analyzed by binary phase diagrams. The article systematically discussed the role of each element in the different working temperatures within the molybdenum alloy. In the temperature range of 0. 4 ~ 0. 7 of melting point: Ti,Zr,Fe and other elements dissolved in the molybdenum matrix blocked the crossslip of dislocations through lattice distortion. The transferred and dispersed oxides as the second phase pinned the subgrain boundaries and grain boundaries,inhibiting the formation of large-angle grain boundaries that was required for recrystallization nucleation and at the same time,occupied the recrystallized nucleation site to achieve tissue strengthening;above 0. 7 of the melting point,Mainly improving the interatomic bonding force in the metal lattice and thereby improving the self-diffusion activation energy obtained the ultra-high temperature working strength and the W element had an advantage in this way. We expected to guide the alloying direction of molybdenum and to finely formulate the types and contents of additives at different working temperatures by using the phase diagrams to find the most accurate and efficient alloying road.