交变电流频率对原位合成Al3Ti/Al复合材料组织及性能的影响

Effect of Alternating Current Frequency on Microstructure and Properties of In-situ Synthesized Al3Ti/Al Composites

以金属铝为基体,以钛纤维为反应源制得铸态的钛铝预制复合体,通过对其施加不同频率的交变电流,在外场作用下促进铝、钛原子间的反应,以期获得Al3Ti颗粒增强铝基复合材料。通过差热分析(DTA)预判钛铝间反应温度为800℃左右,通过XRD、SEM和磨损测试对所得复合材料进行分析表征。结果表明:原位反应最佳参数为:频率7kHz、电流8 A、反应时间5 min。此参数下,钛纤维反应完全,主要相Al3Ti分散性较好,颗粒细化至3μm左右;在10 N载荷条件下,随着频率的增大,摩擦系数先降后升,在频率的7 kHz时摩擦系数最低,为0.2,磨损量最少,耐磨性能最优。

Using metal Al as matrix and titanium fiber as reactive source,an Al3Ti/Al composite was fabricated by applying induction heating,and the inductive magnetic field generated by the coil was used to promote the in-situ reaction rate of aluminum and titanium.The reaction temperature was preliminarily judged by differential thermal analysis(DTA)to be about 800°C,and the obtained samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM)and wear testers.The results show that when the alternating current frequency is 7 kHz,the current is 8 A,and the time is 5 min,the titanium fiber reacts with Al completely,and the dispersed distribution of Al3Ti particles are in-situ obtained,and the average size of the particles reaches 3μm.Under the condition of 10 N load using air as a medium,the friction coefficient decreases first and then increases with the increase of alternating current frequency.The friction coefficient at the frequency of 7 kHz is the lowest value of 0.2,the wear amount is the least,and the wear resistance is optimal.