摘要
以Ti-Al-Ti_3AlC_2为反应体系,采用真空热压技术(1100℃×1 h)制备Ti_2AlC/TiAl基复合材料。借助XRD、SEM等测试手段分析相组成以及微观结构,并测量其密度、维氏硬度、抗弯强度、抗压强度和断裂韧性等室温力学性能。结果表明,产物主要由TiAl、Ti_2AlC和Ti_3Al相组成。利用Ti_3AlC_2分解反应原位自生的Ti_2AlC增强相主要分布于基体晶界处,部分钉扎于晶内,且随着Ti_2AlC生成量的增大,团聚现象加剧。室温力学性能测试表明,Ti_2AlC/TiAl基复合材料的力学性能明显优于单相TiAl材料,当Ti_3AlC_2掺杂量为10 mass%时,综合性能较好,密度、硬度、抗弯强度、抗压强度和断裂韧性分别为3.97 g/cm^3、4.82 GPa、488.61 MPa、1340 MPa和5.68 MPa·m^(1/2)。断裂机制主要表现为沿晶断裂、穿晶断裂、裂纹偏转与桥联;颗粒相增韧、裂纹偏转与桥联以及层状增韧是主要的增韧方式。
Ti2AlC/TiAl composites were fabricated by vacuum hot pressing technique in the Ti-Al-Ti3 AlC2system at 1100 ℃ for 1 h.Phase constituent and microstructure of the composites were analyzed by XRD,OM and SEM. The room temperature mechanical properties such as the density,Vickers hardness,flexural strength,compressive strength and fracture toughness were measured. The results reveal that the products are mainly composed of Ti3 Al,Ti2AlC and TiAl phases. In situ Ti2 AlC reinforcements developed by decomposition reaction of Ti3 AlC2are mainly distributed in the matrix grain boundaries,part of which pinning in the intracrystalline. With the increase of Ti2 AlC content,the agglomeration phenomenon aggravates gradually. The room temperature mechanical properties tests indicate that the mechanical properties of the Ti2 AlC/TiAl composites are obviously superior to the single-phase TiAl material. The Ti2 AlC/TiAl composites with 10 mass% Ti3 AlC2additive presents better comprehensive performance,and the density,Vickers hardness,flexural strength,compressive strength and fracture toughness are 3. 97 g/cm^3,4. 82 GPa,488. 61 MPa,1340 MPa and 5. 68 MPa·m1/2,respectively. The fracture mechanism of the Ti2 AlC/TiAl composites is mixed with many kinds of fracture mode, including intergranular fracture,transgranular fracture,crack deflection and crack bridging. The toughening ways mainly include particulates-toughening,crack deflection and bridging toughening,and laminated-toughening.
作者
王维
艾桃桃
冯小明
李文虎
蒋鹏
袁新强
孛海娃
景然
WANG Wei AI Tao-tao FENG Xiao-ming LI Wen-hu JIANG Peng YUAN Xin-qiang BO Hai-wa JING Ran(School of Materials Science and Engineering, Shaanxi Sci-Tech University, Hanzhong 723000, Chin)
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2017年第3期10-15,共6页
Transactions of Materials and Heat Treatment
基金
国家自然科学基金面上项目(51671116)
陕西省自然科学基础研究计划重点项目(2016JZ016)
陕西省教育厅自然科学重点科学研究计划项目(16JS018)
陕西省青年科技新星科技计划项目(2014KJXX-75)
陕西理工大学科研计划项目(SLGQD16-04)
