W+Nb对Fe-Ni因瓦合金膨胀性能和显微硬度的影响

Effects of W+Nb on Thermal Expansion Property and Microhardness of Fe-Ni Invar Alloy

摘要:

依据磁致伸缩理论和细晶强化方法，选取了具有细化晶粒作用的顺磁性元素W、Nb，借助热力学计算软件Factsage进行合金辅助设计，以FeNi36为基础，通过W+Nb二元合金化熔炼、锻打成形及热处理等工艺，制取具有低膨胀系数、高强度的膨胀合金，并根据试样化学分析、金相和电镜扫描、晶粒度、显微硬度以及膨胀系数等检测结果，研究了合金低膨胀和高强度的机理。结果表明：W+Nb具有良好的细化晶粒作用，能够使基体保持低的膨胀系数和高的显微硬度。

Abstract:

The elements W and Nb with paremagnetism and grain refinement was selected according to the magnetostrictive theory and the fine grain strengthening method. The thermodynamic software Factsage was used in alloy aided design. The samples with a low coefficient of thermal expansion (CTE) and a high strength were made by W+Nb binary alloying of FeNi36, forging and heat treatment. The mechanism of the low coefficient of thermal expansion and the high strength was analyzed by means of the results of Chemical analysis, metallographic and scanning electron microscopy, grain size, microhardness and CTE testing. The result shows that the elements of W+Nb have good grain refinement effect, the binary alloying can make the microhardness of matrix improved and maintain it at the lower CTE.