(1. 中國工程物理研究院 總體工程研究所，綿陽 621999；
2. 西南科技大學(xué) 工程材料與結(jié)構(gòu)沖擊振動(dòng)四川省重點(diǎn)實(shí)驗(yàn)室，綿陽 621999)
摘 要: 鎳基高溫合金廣泛應(yīng)用于制造軍事和民用工程領(lǐng)域中的關(guān)鍵熱端部件，在服役過程中內(nèi)部沉淀相容易發(fā)生粗化，并導(dǎo)致材料力學(xué)性能退化。本文結(jié)合有限元模擬和機(jī)理分析，研究鎳基高溫合金材料發(fā)生沉淀相粗化之后的硬度變化特性，并探討相關(guān)變化與材料微結(jié)構(gòu)演化的關(guān)聯(lián)。結(jié)果表明：合金硬度隨沉淀相粗化的發(fā)生而顯著退化，并呈現(xiàn)出各向異性特征，總體來說，當(dāng)沉淀相體積分?jǐn)?shù)較低或沉淀相粗化程度不高時(shí)，其硬度隨加載角度增大而先逐漸增加后又逐漸降低；而對(duì)于沉淀相體積分?jǐn)?shù)和沉淀相粗化程度均較高的合金，硬度則隨加載角度增大而單調(diào)升高，合金硬度的相關(guān)變化與沉淀相的形狀、大小和分布特性密切相關(guān)；材料微結(jié)構(gòu)的改變導(dǎo)致內(nèi)部位錯(cuò)的形核、增殖和運(yùn)動(dòng)特性發(fā)生變化，進(jìn)而影響宏觀材料的硬度。
關(guān)鍵字: 鎳基高溫合金；沉淀相粗化；硬度；退化；各向異性
（1. Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang 621999, China;
2. Shock and Vibration of Engineering Materials and Structures Key Laboratory of Sichuan Province, Southwest University of Science and Technology, Mianyang 621999, China）
Abstract:Ni-base superalloys were widely used in the manufacture of the hot-end components in the military and civil engineering. Coarsening of the precipitation phase usually occurs during the service of this kind of precipitate strengthened alloys, and it will induce degradation for their mechanical properties. By integrating with related finite element method (FEM) simulations and mechanism analysis, the present paper focuses on the effect of precipitation phase coarsening on the hardness of Ni-base superalloys, in which the relationship between the evolution of microstructure in the material and its macroscopic mechanical properties was analyzed in detail. After coarsening of the precipitation phase, the results demonstrate that considerable degradation occurs for the hardness of alloys, and the hardness also displays an anisotropic characteristic. In general, when the volume fraction or the coarsening''''s degree of precipitation phase are relatively low, the hardness of alloys increases first and then decreases gradually along with the increase of loading direction. Comparatively, in the case of high volume fraction and high coarsening''''s degree of precipitation phase, the hardness increases monotonously with the loading direction. The related variations of alloy hardness are correlated with the evolution of precipitation phase shape, size and distribution within the alloy. The microstructural evolution changes the manners of the nucleation, multiplication and movement of dislocations within the material, and it further leads to different macroscopic hardness.
Key words: Ni-base superalloy; coarsening of precipitation phase; hardness; degradation; anisotropy
