固溶处理对镍-铬-钼合金力学性能的影响及断口分析

来源期刊：中南大学学报(自然科学版)2004年第3期

论文作者：李溪滨 王丹丹 刘如铁 赵福安

文章页码：353 - 357

关键词：热压;固溶处理;力学性能;断口分析

Key words：hot-pressing; solid-solution treatment; mechanical properties; analysis of fracture

摘    要：采用金相显微镜、X射线衍射和扫描电镜等方法研究了热压成形镍-铬-钼合金固溶前后的金相组织、相的组成、断口形貌,以及固溶处理对合金力学性能的影响。研究结果表明:经1 250℃/4 h固溶处理后的合金全为Ni的固溶体,而未经固溶处理和经1 200℃/4 h固溶处理的合金除了含有Ni的固溶体外,还有单质Mo和一些金属间化合物;未经固溶处理的合金呈脆性断裂,拉伸强度要比固溶后合金的强度低,而固溶后合金呈延性断裂。经1 250℃/4 h和1 200℃/4 h固溶处理后合金显示出以韧窝为主的断口形貌,与合金的延性断裂力学性能测试结果 一致,而未经固溶处理的合金呈现以解理为主的断口形貌,与合金的脆性断裂力学性能测试结果一致。固溶处理前合金的硬度要比处理后的合金硬度高。

Abstract: Optical microscope, X-ray diffraction(XRD) and scanning electron microscope(SEM) were applied to investigate microstructure, phase-constituting, fracture morphology, mechanical properties of the hot-press nickel-chromium-molybdenumalloybefore and aftersolid-solution treatment. The results show that the alloy after solid-solution treatment at 1 250℃/4 h is Ni solid-solution, while the alloys before solid-solution treatment and after solid-solution treatment at 1 250℃/4 h also have Mo and some inter metallic compounds. The alloy after solid-solution treatment has higher tensile strength than that alloy before solid-solution treatment .The microstructure morphologies of the alloy after solid-solution treatment both at 1 200℃/4 h and 1200℃/4 h are ductile dimple, which are consistent with that of ductile fracture, but that of the alloy before solid-solution treatment is brittle cleavage, which is consistent with that of brittle fracture. The hardness before solid-solution treatment is higher than that after solid-solution treatment.