La_(2)O_(3)第二相强化W合金的制备及物理与力学性能  

Preparation, physical and mechanical properties of La_(2)O_(3) second-phase reinforced tungsten alloys

作　　者：付凯超 许荡 桑长城 陈睿智 陈鹏起 程继贵[1,2] FU Kaichao;XU Dang;SANG Changcheng;CHEN Ruizhi;CHEN Pengqi;CHENG Jigui(School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China;Anhui Powder Metallurgy Engineering Technology Research Center,Hefei 230009,China)

机构地区：[1]合肥工业大学材料科学与工程学院,合肥230009 [2]安徽省粉末冶金工程技术研究中心,合肥230009

出　　处：《粉末冶金材料科学与工程》2024年第1期53-62,共10页Materials Science and Engineering of Powder Metallurgy

基　　金：国家重点研发计划资助项目(2022YFE0109700);国家自然科学基金资助项目(52274361)。

摘　　要：第二相强化钨(W)合金具有高强度、良好的抗蠕变和抗辐照等优异性能,是一种极具潜力的聚变堆面向等离子体材料。本文以偏钨酸铵和硝酸镧(La(NO3)3)为主要原料,采用溶液燃烧合成法(solution combustion synthesis,SCS)制备不同La_(2)O_(3)掺杂量(w(La_(2)O_(3))=0~1.5%)的W-La_(2)O_(3)复合粉末,并通过放电等离子烧结制备La_(2)O_(3)第二相强化W合金,研究La_(2)O_(3)含量对W合金微观组织与力学性能的影响。结果表明:通过SCS可制备出平均粒径约200 nm、分散性好、La_(2)O_(3)均匀分布的W-La_(2)O_(3)复合粉末。适量La_(2)O_(3)的加入可有效改善W合金的物理和力学性能。随La_(2)O_(3)含量增加,La_(2)O_(3)第二相强化W合金的显微硬度和抗拉强度均呈现先升高后降低的趋势,相对密度则逐渐降低。w(La_(2)O_(3))=0.5%时,W5La合金的显微硬度(HV)达到最大值524.10。引入La_(2)O_(3)第二相后,W基体的断裂方式由W晶粒断裂为主转变为沿晶断裂和穿晶断裂共同存在的混合型断裂,并且晶粒尺寸有所减小,平均晶粒尺寸为4.1μm。与纯W相比,W5La合金具有更高的抗拉强度和更低的韧脆转变温度(ductile-brittle transition temperature,DBTT),其室温和500℃的抗拉强度分别为279.6 MPa和498.9 MPa,DBTT为200~300℃。Second-phase reinforced tungsten(W)alloy has excellent properties such as high strength,great creep resistance,and irradiation resistance,it is a highly promising plasma facing material for fusion reactor.In this paper,W-La_(2)O_(3)composite powders with different La_(2)O_(3)contents(w(La_(2)O_(3))=0-1.5%)were prepared by solution combustion synthesis(SCS)using ammonium metatungstate and lanthanum nitrate(La(NO3)3)as the main raw materials.Then the La_(2)O_(3)second-phase reinforced W alloys were further prepared by spark plasma sintering,and the effects of La_(2)O_(3)content on the microstructures and mechanical properties of the W alloys were investigated.The results show that W-La_(2)O_(3)composite powders with average particle size of approximately 200 nm,well dispersion,and uniform distribution of La_(2)O_(3)can be successfully synthesized using SCS.The addition of appropriate amount of La_(2)O_(3)can effectively improve the physical and mechanical properties of W alloys.With the increase of La_(2)O_(3)contents,the microhardness and tensile strength of the La_(2)O_(3)second-phase reinforced W alloys show a tendency that increases first and then decreases,while the relative density gradually decreases.The microhardness(HV)of W5La alloy reaches the maximum value of 524.10 at w(La_(2)O_(3))=0.5%.After the addition of the second-phase of La_(2)O_(3),the fracture mode of the W matrix is changed from W grain fracture predominantly to a mixed fracture with the co-existence of intergranular fracture and transgranular fracture,and the grain size is reduced with an average grain size of 4.1μm.Compared with pure W,W5La alloy has higher tensile strength and lower ductile-brittle transition temperature(DBTT),and its tensile strength at room temperature and 500℃is 279.6 MPa and 498.9 MPa,respectively,and DBTT is 200-300℃.

关 键 词：La_(2)O_(3)掺杂W粉 面向等离子体材料 溶液燃烧合成 放电等离子烧结 力学性能 

分 类 号：TB331[一般工业技术—材料科学与工程]