文章信息/Info

Title:

Microstructural Design and Property Optimizationof Mo Alloys with High Performance

作者:

 劉剛1; 張國君1; 2; 江峰1; 丁向東1; 孫院軍3; 王林3; 羅建海3; 孫軍1

 （1. 西安交通大學 金屬材料強度國家重點實驗室, 陜西 西安 710049）
（2. 西安理工大學 材料科學與工程學院, 陜西 西安 710048）
（3. 金堆城鉬業集團有限公司，陜西 西安 710077）

Author(s):

LIU Gang1;  ZHANG Guojun1; 2;  JIANG Feng1; DING Xiangdong1; SUN Yuanjun3; WANG Lin3; LUO Jianhai3; SUN Jun1

 （1. State Key Laboratory for Mechanical Behavior of Materials, Xi�餫n Jiaotong University, Xi�餫n 710049, China）
(2. School of Materials Science and Engineering, Xi�餫n University of Technology, Xi�餫n 710048, China)
(3. Jinduicheng Molybdenum Group Co��,LTD，Xi�餫n 710077, China)

關鍵詞:

鉬合金; 強韌化; 納米稀土氧化物; 液液摻雜; 多層級微觀結構; 高延性

DOI:

10.7502/j.issn.1674-3962.2016.03.06

文獻標志碼:

A

摘要:

傳統方法制備的稀土氧化物彌散強化鉬合金(ODS鉬合金)強度有限且塑性較差，導致其變形深加工能力不足，嚴重制約了其工業應用。分析了ODS鉬合金制備工藝-微觀組織-力學性能之間的因果關系，提出了鉬合金納米摻雜強韌化的新思路，即納米尺度稀土氧化物顆粒均勻彌散分布在細晶鉬基體晶粒內部、同時部分顆粒分布在晶界上的多層級微觀結構優化原則，發展了制備該類新型鉬合金的液液摻雜方法，所得到的高性能鉬合金在拉伸屈服強度達到800 MPa量時，拉伸延伸率仍近40%，與傳統方法制備的ODS鉬合金相比，屈服強度提高了約15%，拉伸延伸率提高了逾160%，實現了強度和延性的同步提升。進一步建立了強韌化理論模型，對強度和延性的改善進行了量化描述。這種高性能鉬合金由于力學性能優異、加工性能好，已獲得了工業應用，其微觀組織調控原則以及制備方法對其它難熔金屬結構材料的高性能化同樣具有借鑒意義。

Abstract:

The high�瞭emperature stability and mechanical properties of refractory molybdenum alloys are highly desirable for a wide range of critical applications. But molybdenum (Mo) alloys are also a well�瞜nown example of body�瞔entered�瞔ubic materials that suffer from low ductility and limited formability. In this paper, we firstly discuss the microstructure�瞤roperty relationships in traditional oxide dispersion�瞫trengthened Mo alloys and analyze the fracture mechanisms. Based on these understandings, we propose a new nanostructuring strategy to solve the long�瞫tanding low�瞕uctility problem by optimizing the distribution of the grains, strengthening dispersions and solutes. In particular, a simple and cost�瞖ffective molecular�瞝evel liquid�瞝iquid mixing/doping technique is developed to achieve ultrafine submicron�瞫ized grains with nanosized oxide particles uniformly distributed in the grain interior. The resulting nanostructured Mo alloys boast not only a high yield strength of over 800 MPa but at the same time an extraordinary tensile elongation as large as ~40% at room temperature, which is increased by about 15% and above 160%, respectively, when compared with the ODS Mo alloys prepared by conventional methods. The new processing route can be readily adapted for large�瞫cale industrial productions of ductile Moalloys that can be extensively processed and shaped, including deep drawing, at low temperatures. Our findings represent a pathway towards engineering dispersion�瞫trengthened materials with simultaneously high strength and ductility, a combination beyond conventional trends and expectations, which should be applicable to refractory metals such as tungsten.