| 引用本文: | 张捷,顾海,孙健华,陆亮亮,李彬,孙中刚.激光熔化沉积制备TiB+TiC/Ti6Al4V复合材料微观组织研究[J].材料科学与工艺,2021,29(6):42-48.DOI:10.11951/j.issn.1005-0299.20210166. |
| ZHANG Jie,GU Hai,SUN Jianhua,LU Liangliang,LI Bin,SUN Zhonggang.Microstructure of TiB+TiC/Ti6Al4V composite prepared by laser melting deposition[J].Materials Science and Technology,2021,29(6):42-48.DOI:10.11951/j.issn.1005-0299.20210166. |
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| 激光熔化沉积制备TiB+TiC/Ti6Al4V复合材料微观组织研究 |
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张捷1,2,顾海1,2,孙健华1,陆亮亮3,李彬1,2,孙中刚1
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(1.南通理工学院 机械工程学院,江苏 南通 226002; 2.江苏省3D打印装备及应用技术 重点建设实验室,江苏 南通 226002; 3.南通产业技术研究院,江苏 南通 226019)
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| 摘要: |
| 激光熔化沉积制备的钛合金微观组织中常出现异常粗大的柱状晶粒,限制了其在复杂承力结构件方面的应用。为降低原始晶粒的尺寸,提高合金强度,本文基于原位自生反应原理,在Ti6Al4V粉末中添加少量的颗粒增强体B4C得到混合粉末,并通过激光熔化沉积工艺制备出熔覆层以及多层钛基复合材料(TMC)。利用光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)和显微硬度仪等测试手段研究了B4C的添加对Ti6Al4V合金微观组织的影响规律,并对其作用机制进行了分析。研究表明:B4C的添加降低了原始β晶粒的尺寸,并强化了合金基体。当添加1wt.% B4C颗粒时,晶粒的外延生长得到有效抑制,原始β晶粒开始出现柱状晶向等轴晶转变(CET)的趋势,柱状晶粒尺寸由原始的平均600 μm减小到50 μm。同时,B4C与钛基体发生原位反应形成的混杂增强相TiB和TiC富集在晶界,构成三维网状结构,不仅限制了晶内α相的生长,同时也起到了第二相强化的作用,使基体的硬度较基材提高了15 %以上。 |
| 关键词: 钛基复合材料 增材制造 激光熔化沉积 B4C添加 显微组织 |
| DOI：10.11951/j.issn.1005-0299.20210166 |
| 分类号:TB331 |
| 文献标识码:A |
| 基金项目:江苏省高校自然科学研究面上项目(21KJD460005)；南通市科技计划项目(JCZ20056,JC2020149,JC2020132)；南通理工学院省级科技服务平台培育项目；江苏省产学研合作项目(BY2020545)；江苏高校“青蓝工程”(苏教师［2019］3号)；江苏省科技计划项目(BE2018010-4). |
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| Microstructure of TiB+TiC/Ti6Al4V composite prepared by laser melting deposition |
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ZHANG Jie1,2, GU Hai1,2, SUN Jianhua1, LU Liangliang3, LI Bin1,2, SUN Zhonggang1
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(1.School of Mechanical Engineering, Nantong Institute of Technology, Nantong 226002, China; 2.Jiangsu Key Laboratory of 3D Printing Equipment and Application Technology, Nantong 226002, China; 3.Nantong Industrial Technology Institute, Nantong 226019, China)
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| Abstract: |
| In the microstructure of titanium alloys prepared by laser melting deposition (LMD), the columnar grains are often very large, which restricts its application in complex load-bearing structures. In order to reduce the size of the original grains and increase the strength of the alloys, based on the principle of in-situ autogenous reaction, a small amount of particle reinforcement B4C was added to Ti6Al4V powder to obtain a mixed powder, and a cladding layer and a multi-layer titanium matrix composite (TMC) were prepared by an LMD process. Using optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM), and microhardness tester, the influence of B4C addition on the microstructure of Ti6Al4V alloy was studied and its mechanism was analyzed. Results show that B4C addition not only refined the original β grains, but also strengthened the alloy matrix. When B4C addition was 1wt.%, the epitaxial growth of the grains was effectively restrained, the original β grains experienced a trend of columnar grains to equiaxed grains transformation (CET), and the average diameter of the columnar grains reduced from 600 μm to 50 μm. At the same time, the hybrid reinforced phases TiB and TiC formed by the in-situ reaction between B4C and titanium matrix enriched in the grain boundaries and formed a three-dimensional network structure, which not only restricted the growth of intracrystalline α phase, but also realized a second phase strengthening, leading to the increase in the hardness of the matrix by more than 15% compared with the base material. |
| Key words: titanium matrix composite additive manufacturing laser melting deposition B4C addition microstructure |
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