原位自生2%TiB_(2)颗粒对2024Al增材制造合金组织和力学性能的影响  

Effect of In Situ 2%TiB_(2) Particles on Microstructure and Mechanical Properties of 2024Al Additive Manufacturing Alloy

作　　者：孙腾腾 王洪泽 吴一[1,2] 汪明亮 王浩伟[1,2] SUN Tengteng;WANG Hongze;WU Yi;WANG Mingliang;WANG Haowei(State Key Laboratory ofMetal Matrix Composites,School ofMaterials Science and Engineering.Shanghai Jiao Tong University,Shanghai 200240,China;Institute ofAlumics Materials,Shanghai Jiao Tong University(Anhui),Huaibei 235000,China)

机构地区：[1]上海交通大学材料科学与工程学院金属基复合材料国家重点实验室,上海200240 [2]上海交通大学安徽(淮北)陶铝新材料研究院,淮北235000

出　　处：《金属学报》2023年第1期169-179,共11页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.52075327和52004160;上海市青年科技英才杨帆计划项目No.20YF1419200;上海市自然科学基金项目No.20ZR1427500;淮北市重大科技项目No.Z2020001;上海同步辐射光源BL13W1线站项目No.2020-SSRF-PT-012107

摘　　要：采用激光粉末床熔化(laser powder bed fusion,L-PBF)工艺制备含2%(质量分数)原位自生TiB_(2)颗粒的2024Al-2%TiB_(2)合金和难打印2024Al合金,研究了TiB_(2)颗粒对经固溶(510℃处理1 h后水冷)和T6 (固溶处理后人工时效)热处理后增材制造2024Al合金组织和室温拉伸性能的影响。由于L-PBF冷却速率较快以及TiB_(2)颗粒的添加,2024Al-2%TiB_(2)合金微观组织以等轴晶为主,平均晶粒尺寸约为5.8μm。T6热处理之后,2024Al合金的抗拉强度、屈服强度和伸长率分别为(261.3±4.3) MPa、(252.6±2.5) MPa和(0.3±0.1)%;2024Al-2%TiB_(2)合金抗拉强度、屈服强度和伸长率分别达到(458.2±6.5) MPa、(398.4±2.7) MPa和(3.4±0.4)%;2种合金中析出大量均匀分布、尺寸细小的长条状析出相。T6态2024Al-2%TiB_(2)增材制造合金的抗拉强度与2024Al增材制造合金相比提高75.5%,其强度与2024Al锻造合金强度相当。合金的主要强化机制是位错强化、晶界强化、析出相强化和TiB_(2)颗粒带来的Orowan强化以及载荷传递强化,2种合金热处理后的拉伸断裂失效主要由缺陷控制。原位自生2024Al-2%TiB_(2)增材制造合金成形性较好,经热处理后获得较高的综合室温拉伸性能。Laser powder bed fusion(L-PBF) is an innovative additive manufacturing method with great potential for fabricating complex geometrical components with integrated functionalities. In the aerospace industry, the Al-Cu-Mg(2024Al) alloy is widely used because of its excellent mechanical properties and low density;however, its disadvantages include low printability and high crack susceptibility. This work investigates the effects of in situ TiB_(2) particles on the microstructure and tensile properties of the solution-treated(510℃ treat 1 h and then cooling by water) and T6-treated(i.e., solution and aging treatments) L-PBF fabricated 2024Al alloy at room temperature. Equiaxed grains with an average size of approximately 5.8 μm dominate in the printed 2024Al-2%TiB_(2) alloy because of the high cooling rate during the L-PBF process and the heterogeneous nucleation effect of the TiB_(2) particles. After the T6 heat treatment, many uniformly distributed, fine, and long precipitation strips formed in both the 2024Al and 2024Al-2%TiB_(2) alloys. The 2024Al-2%TiB_(2) alloy has ultimate tensile and yield strengths of(458.2 ± 6.5)and(398.4 ± 2.7) MPa, respectively;further, it has a maximum elongation of(3.4 ± 0.4)%. These parameters indicate a substantial improvement in the strength and elongation of the 2024Al-2%TiB_(2) alloy compared to those of the 2024Al alloy. Furthermore, the mechanical properties of the T6-treated 2024Al-2%TiB_(2) alloy are comparable to those of the wrought T6-treated 2024Al-T6 alloy. The main strengthening mechanisms of the 2024Al-2%TiB_(2) alloy include solid solution strengthening, dislocation strengthening,grain boundary strengthening, precipitation strengthening, Orowan strengthening, and load-bearing strengthening induced by TiB_(2) particles. In conclusion, 2024Al-2%TiB_(2) alloy manufactured using the L-PBF method provides excellent printability and room-temperature tensile properties.

关 键 词：激光粉末床熔化 2024Al合金 原位自生TiB_(2)颗粒 热处理 拉伸性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]