Microstructure and high temperature tensile properties of (TiC+TiB) reinforced titanium matrix composites by vacuum induction suspension melting
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摘要: 利用真空感应悬浮熔炼炉制备了(TiC+TiB)/Ti-6Al-4Sn-8Zr-0.8Mo-1.5Nb-1W-0.25Si复合材料,增强体占比分别为0%、2%、4%(体积比)。利用金相显微镜、SEM、XRD、TEM和高温拉伸试验机研究了其显微组织和高温拉伸性能。结果表明:钛合金主要由α-Ti相和Ti2ZrAl相组成,Ti2ZrAl相分布在α-Ti片层交界位置。同时,复合材料中还存在多边形块状TiC和TiB长晶须。钛合金组织为典型的魏氏组织,在β-Ti晶粒内α-Ti相长成近平行排列的长针状。钛基复合材料中随着增强体数量增加,α-Ti长径比显著减小,β-Ti晶粒细化。在650~700 ℃范围钛基复合材料强度显著提高,2%增强体复合材料在650 ℃强化效果最优,4%增强体复合材料在700 ℃强化效果最优。温度超过700 ℃后,增强体强化效果减弱。复合材料塑性总体较低。钛基复合材料强化方式为细晶强化、固溶强化和载荷传递强化。高温拉伸时钛基复合材料的断裂方式为脆性断裂。Abstract: (TiC+TiB)/Ti-6Al-4Sn-8Zr-0.8Mo-1.5Nb-1W-0.25Si titanium matrix composites were prepared by vacuum induction suspension melting, with the reinforcement composition volume ratio respectively at 0%, 2% and 4%. The microstructure and high temperature tensile properties of the composites were investigated by metallographic microscope, SEM, XRD, TEM and high temperature tensile testing machine. The results show that the titanium alloy is mainly composed of α-Ti phase and Ti2ZrAl phase, and the Ti2ZrAl phase is distributed at the junction of α-Ti flakes. In addition, there also exist polygonal bulk TiC and long TiB whiskers. The microstructure of the titanium alloy is typical widmandgren structure, and the α-Ti phase presents long needlelike shape with nearly parallel arrangement in the β-Ti grains. In titanium matrix composites, with the increase of reinforcement composition, the length to diameter ratio of α-Ti significantly decreases, and the grain size of β-Ti is refined. The strength of titanium matrix composites is increased significantly at 650~700 ℃. The best strengthening effect appears at 650 ℃ for the composites with 2% reinforcement composition while at 700 ℃ for the composites with 4% reinforcement composition. When the temperature exceeds 700 ℃, the strengthening effect of the reinforcement composition is weakened. The plasticity of the composites is generally low. The strengthening mechanism of the titanium matrix composites are attributed to the grain refinement, solid solution strengthening and load transfer strengthening. The fracture mode of the titanium matrix composites is brittle fracture under high temperature tensile conditions.
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表 1 不同增强体比例钛基复合材料中α-Ti相衍射峰位置
Table 1. Peak position of α-Ti phase in titanium matrix composite materials with different reinforcement composition ratios
标准α-Ti衍射峰位置/(°) 钛合金及复合材料衍射峰位置/(°) 0BC 2BC 4BC 35.093 34.794 34.675 35.004 38.421 37.892 37.721 37.919 40.170 39.822 39.744 39.967 53.004 52.637 52.533 52.728 62.949 62.865 62.879 62.886 70.660 70.179 70.074 70.219 76.218 75.984 76.062 76.088 77.368 77.203 77.199 77.493 82.290 81.653 81.481 81.471 86.759 86.427 86.620 86.684 注:0BC、2BC、4BC分别代表增强体添加比例为0、2%、4%。 表 2 钛基复合材料高温拉伸性能
Table 2. High temperature tensile properties of titanium matrix composites
编号 Rm/MPa Rp0.2/MPa A/% 650 ℃ 700 ℃ 750 ℃ 650 ℃ 700 ℃ 750 ℃ 650 ℃ 700 ℃ 750 ℃ 0BC 655.602 567.213 488.085 555.3 491.75 387.5 1.75 1.45 1.55 2BC 707.234 599.885 496.379 627.5 499.55 383.25 1.7 0.5 1.1 4BC 772.363 693.464 433.342 679.3 594.9 358.9 1.6 1.15 0.6 注:0BC、2BC、4BC分别代表增强体添加比例为0、2%、4%。 -
[1] Zhang Changjiang, Lin Sibo, Zhang Shuzhi, et al. Effect of TiC on microstructure and mechanical properties of high-temperature titanium matrix composites[J]. Rare Metal Materials and Engineering, 2017,46(S1):185−189. (张长江, 林思波, 张树志, 等. TiC含量对高温钛基复合材料组织功能性能的影响[J]. 稀有金属材料与工程, 2017,46(S1):185−189. [2] Yi Meng, Zhang Xiangzhao, Liu Guiwu, et al. Comparative investigation on microstructures and mechanical properties of (TiC+TiB)/Ti-6Al-4V composites from Ti-B4C-C and Ti-TiB2-TiC systems[J]. Materials Characterization, 2018,140:281−289. doi: 10.1016/j.matchar.2018.04.010 [3] Zhang Changjiang, Zhang Shuzhi, Hou Zhaoping, et al. Tensile mechanical behavior and failure mechanism of (TiBw+TiCp)/Ti compsites at elevated temperature[J]. The Chinese Journal of Nonferrous Metals, 2016,26(11):2288−2295. (张长江, 张树志, 候赵平, 等. (TiBw+TiCp)/Ti复合材料高温拉伸力学行为与失效机理[J]. 中国有色金属学报, 2016,26(11):2288−2295. [4] 杨明华. 650~750 ℃短时高温钛合金成分优化及组织性能研究[D]. 哈尔滨: 哈尔滨工业大学, 2015: 16−21.Yang Minghua. Composition optimization and microstructure and mechanical properties of high temperature alloys for short-term use at 650~700 ℃[D]. Harbin: Harbin Institute of Technology, 2015: 16−21. [5] 刁雨薇. Ti-Al-Sn-Zr-Mo-Nb-W-Si高温钛合金700 ℃拉伸行为研究[D]. 北京: 北京有色金属研究总院, 2019: 18−30.Diao Yuwei. The study on tensile behavior of Ti-Al-Sn-Zr-Mo-Nb-W-Si high temperature titanium alloy at 700 ℃[D]. Beijing: General Research Institute for Nonferrous Metals, 2019: 18−30. [6] 曹磊. 熔铸法制备TiC/Ti-6Al-4V复合材料组织与力学性能研究[D]. 哈尔滨: 哈尔滨工业大学, 2010: 1−6.Cao Lei. Research on microstructure and mechanical properties of TiC/Ti-6Al-V composties fabricated by melting-casing process[D]. Harbin: Harbin Institute of Technology, 2010: 1-6. [7] Cui Yapeng, Chen Ziyong, Ma Xiaozhao, et al. Microstructures and mechanical properties of a new type of high temperature titanium alloy[J]. Materials Science Forum, 2020,993:208−216. doi: 10.4028/www.scientific.net/MSF.993.208 [8] 张喜燕, 赵永庆, 白晨光. 钛合金及应用[M]. 北京: 化学工业出版社, 2005: 140.Zhang Xiyan, Zhao Yongqing, Bai Chenguang. Titanium and its application[M]. Beijing: Chemical Industry Press, 2005: 140. [9] 叶园. Zr含量对650 ℃短时高温钛合金显微组织和力学性能的影响[D]. 哈尔滨: 哈尔滨工业大学, 2020: 21-50.Ye Yuan. Effect of Zr content on microstructure and mechanical properties of high temperature titanium alloys for short-temperature at 650 ℃[D]. Harbin: Harbin Institute of Technology, 2020: 21-50. [10] 宋卫东, 王成, 毛小南. 颗粒增强钛基复合材料-加工制备、性能与表征[M]. 北京: : 科学出版社, 2017: 114.Song Weidong, Wang Cheng, Mao Xiaonan. Preparation, properties and characterization of particle reinforced titanium matrix composites [M]. Beijing: Science Press, 2017: 114. [11] Wang Xiaopeng, Chen Yuyong, Xu Lijuan, et al. Ti-Nb-Sn-hydrotherapy composites synthesized by mechanical alloying and high frequency induction heated sintering[J]. Journal of the Mechanical Behavior of Biomedical Materials, 2011,(4):2074−2080. [12] 李冲. 原位合成TiC及TiC+TiB增强TB8钛基复合材料组织与性能研究[D]. 镇江: 江苏大学, 2020: 21-22.Li Chong. Research on microstructure and properties of in-situ synthesized TiC and TiC+TiB reinforced TB8 titanium matrix composites[D]. Zhenjiang: Jiangsu University, 2020: 21-22. [13] Zhang Lei, Yu Jiashi, Xu Kaixuan, et al. Microstructure and microhardness of (GNPs+B)/TC4 titanium matrix composites[J]. Titanium Industry Progress, 2021,38(3):12−16. (张雷, 于佳石, 许凯旋, 等. (GNPs+B)/TC4复合材料组织和硬度研究[J]. 钛工业进展, 2021,38(3):12−16. [14] 曹洪川. 石墨烯增强钛基复合材料的强塑性及摩擦磨损性能研究[D]. 贵阳: 贵州大学, 2020: 31.Cao Hongchuan. Study on the strength plasticty and frictionand and wear properties of graphene-reinforced titanium matrix composites[D]. Guiyang: Guizhou Uniersity, 2020: 31. [15] Li YueYing, Fu Wenzhu, Zhen Liangqiao. Study on mechanical alloying of TiB2 particulate reinforced titanium matrix composite[J]. Applied Mechanics and Materials, 2018, 4579:41−46. [16] 何永亮, 张志勇, 张福利, 等. 真空感应悬浮炉关键技术及装备的发展与应用[C]// 2018中国铸造活动周论文集. 苏州: 中国机械工程学会铸造分会, 2018: 1−4.He Yongliang, Zhang Zhiyong, Zhang Fuli, et al. Development and application of key technology and equipment of the vacuum induction levitation furnace[C]// 2018 China Casting Activity Week Proceedings. Suzhou: The Foundry Institution of China Mechanical Engineering Society, 2018: 1−4. -