釕元素對鎳基超合金在中溫及高溫潛變性能影響之研究

Influence of Ruthenium Element on Intermediate and High Temperature Creep Properties of a Nickel-base Superalloy

廖健鴻(J. H. Liao) ； 薄慧雲(H. Y. Bor) ； 倪國裕(G. Y. Ni) ； 魏肇男(C. N. Wei) ； 鄭文興(V. S. Jeng)

《鑄造工程學刊》 41卷2期 (2015/06) Pp. 24-30

摘要

在鎳基超合金之發展上，早期合金之發展主要是增加γ’析出強化相數量，來提昇合金強度，但γ’相之體積分率僅能提昇至65－70%即到達瓶頸，因此最新的超合金成份設計，主要是添加5wt.%以上之錸元素，以固溶強化γ基地之方式，來強化合金之強度。但錸元素的添加容易使鎳基超合金在高溫長時間之作用下產生拓撲密堆（TCP）有害相，進而影響到合金之潛變性能。本研究以含有5wt.%錸之Ni-10Co-10W-8.4Cr-5.5Al-5Re-3Ta-1.3Hf-1Ti-0.7Mo-0.14C合金為素材，添加不同含量的釕元素於合金中，研究釕元素對鎳基超合金在中溫／高應力（760℃／724MPa）及高溫／低應力（982℃／200MPa）潛變性能之影響。結果顯示添加釕具有消除拓撲密堆有害相的效果，其中以添加3wt.%釕的效果最好，可有效延長合金之中溫／高應力及高溫／低應力潛變壽命。

關鍵字

釕 ； 超合金 ； 鎳 ； 潛變

並列摘要

In the early development of Ni-base superalloy, the strength of alloy was increased by increasing the amount of γ‘ precipitate. However, theγ‘ phase was limited to approximately 65-70% volume fraction to maximize precipitation strength. Recent researches showed that further improvement in the strength can be achieved through solid solution strengthening of theγ matrix, e.g., by adding over 5 wt.% Re element. However, if the Re element was excessive, it tended to promote the formation of deleterious topological closed-packed (TCP) phases at the long-term elevated temperatures exposures, resulting in a decrease in the creep properties. In this study, alloys based on Ni-10Co-10W-8.4Cr-5.5Al-5Re-3Ta-1.3Hf-1Ti-0.7Mo-0.14C alloy which was contained 5 wt.% Re. and various Ru elements were added to base alloy. The purpose of this investigation was to determine the influence of Ru on the intermediate temperature - high stress (760℃/724MPa) and high temperature - low stress (982℃/200MPa) creep properties of alloy. The results showed that the addition of 3 wt.% Ru significantly prevented the formation of TCP phase and prolonged the creep life of alloy.

並列關鍵字

ruthenium ； superalloy ； nickel ； creep