(中南大学 材料科学与工程学院, 长沙 410083)
摘 要: 利用快速凝固粉末冶金方法制备了TiB2颗粒增强Al-8.5Fe-1.3V-1.7Si耐热铝合金试样以及不含TiB2颗粒的基体合金试样, 通过光学显微镜、扫描电镜分析了其显微组织和断口形貌, 采用X射线衍射进行了物相分析, 并进行力学性能测试。结果发现,TiB2颗粒能有效地添加到Al-8.5Fe-1.3V-1.7Si耐热铝合金基体中, 并能有效地抑制平衡相Al13Fe4的析出, 且能细化晶粒, TiB2颗粒的存在使得粒度小于74 μm粉末冶金合金挤压试样的室温强度高达454 1 MPa, 屈服强度达407 8 MPa, 延伸率保持在7.7%; 350 ℃高温强度稳定在210 MPa以上, 延伸率稳定在7.7%以上。
关键字: TiB2; 耐热铝合金; 快速凝固; 粉末冶金
( School of Materials Science and Engineering,
Central South University, Changsha 410083, China)
Abstract: The samples of Al-8.5Fe-1.3V-1.7Si aluminium alloy with and without TiB2 particles reinforcement were prepared by rapid-solidified powder metallurgy. The microstructure and fractography of the samples were studied by means of the optical microscope and scanning electron microscope, and the mechanical properties were analyzed by tensile experiment. The results show that TiB2 particles can be added to the AlFeVSi aluminium alloy and restrains the form of equilibrium phase Al13Fe4 . The crystal grain is refined and the mechanical properties are improved. The samples with TiB2 particles which are smaller than 74 μm show the best mechanical properties.The fracture strength, yield strength and elongation reach to 454 1 MPa, 407 8 MPa, 7.7% respectively at room temperature. The elevated temperature strength and elongation stay stable over 210 MPa and 7.7% at 350 ℃.
Key words: TiB2; heat-resistant aluminium; rapid-solidified; powder metallurgy