Ta和Th掺杂对新型γ′强化铱基高温合金的组织演变与强韧化的影响机制

项目名称： Ta和Th掺杂对新型γ′强化铱基高温合金的组织演变与强韧化的影响机制

项目编号： No.51501075

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 刘毅

作者单位： 昆明贵金属研究所

项目金额： 21万元

中文摘要： 传统的γ′相强化铱基高温合金具有优异的高温力学和抗腐蚀性能，特别适合于航天航空领域中要求耐超高温、抗氧化和抗腐蚀的工作环境，但由于合金强韧性不匹配，限制了其实际应用。近年来，在Ir-Al-W合金体系中发现的新型三元γ′-Ir3(Al,W)相将有可能改变这种现状，为开发下一代新型铱基高温合金提供了一条新的道路。.已有研究发现，Ta元素能进一步强化Ir-Al-W合金中的γ′-Ir3(Al,W)相，Th元素掺杂能有效改善铱合金的高低温塑性。因此，本项目以Ir-Al-W高温合金为研究对象，从合金元素成分分配比出发，系统研究Ta和掺杂Th元素对合金组织结构、高温组织稳定性、高温压缩力学行为、晶界强度和裂纹萌生扩展的影响规律，阐明Ta显著提高γ'相高温稳定性的强化机理及Th元素增加晶界强度的韧化机制等两个关键科学问题，为发展更高承温能力、两相组织和强韧性匹配的新一代铱基高温合金提供理论基础和实验数据。

中文关键词： 铱基高温合金；组织演变；强韧化机制；高温力学性能；裂纹萌生扩展

英文摘要： Traditional γ' phase strengthening iridium-based superalloy having excellent high-temperature mechanical and corrosion resistance, particularly suited to the application in the field of aerospace high-temperature resistant, anti-oxidation and anti-corrosion harsh working environment. However, because the strength and toughness of the alloy does not match, which limits its practical application. In recent years, novel ternary γ'-Ir3(Al, W) phase was reported in Ir-Al-W system, which provides a pathway for the development of this new class of iridium-based superalloy..It has been found that γ'-Ir3(Al,W) phase can be further strengthen by addition of Ta, which can effectively improved the high temperature mechanical property of iridium alloy, and the plasticity of alloy can be effectively improved by doping of Th. In the present study, effect of Ta and doping Th elements on the microstructure evolution, high temperature microstructure stability, high temperature compression mechanical behavior, grain boundaries strength and influence of crack initiation expansion will be investigated systematically in the Ir-Al-W based superalloy. Effect of Ta on high temperature stability of γ'-Ir3(Al,W) phase and toughening mechanism of Th elements will be clarified. This project will provide a fundamental understanding and experimental data accumulation for further developing this new generation iridium-based superalloys with higher temperature capability, ideal for two-phase structure and strength and toughness coordination.

英文关键词： iridium-base superalloy;microstructure evolution;strengthening-toughening mechanisms;high temperature mechanical property;crack initiation expansion