原位合成Al3Ti颗粒增强铝基复合涂层

摘要

以直径200 μm、纯度99.5％的钛丝丝网为反应源,通过熔渗-原位反应法制备一种Al3Ti金属间化合物颗粒增强铝基表面复合涂层.差热分析结果表明,在890°C下,Ti丝和Al熔体间发生反应.采用XRD、SEM以及显微硬度和磨损测试对所得到的复合涂层进行表征.结果表明:当保温时间为20 min时,钛丝反应完全,原位合成为块状和条状的Al3Ti颗粒； 颗粒的显微硬度大约为基体显微硬度的4.5倍；在载荷10 N的干滑动磨损条件下,与没有增强的Al基体相比较,保温20 min所制备的复合涂层表现出较好的耐磨性,其磨损机制为粘着磨损和磨粒磨损共存.%Using titanium wires (99.5％,200 μm in diameter) as a reactive source,an Al-based composite coating reinforced by titanium tri-aluminide (Al3Ti) particles was fabricated by infiltration plus in-situ methods.According to the differential thermal analysis (DTA) curve,the reactive temperature between Ti wires and Al matrix can be determined at 890 °C.The obtained composite coatings were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM),and microhardness and wear test.The experimental results show that when holding period is 20 min at 890 °C,the titanium wires react completely to in-situ synthesize Al3Ti particles,which presents blocky and strip-like states.The microhardness of in-situ synthesized Al3Ti particles is about 4.5 times that of the Al-matrix.Under the condition of dry sliding at 10 N load,compared with the unreinforced Al matrix,the composite coating fabricated with 20 min offers unique wear resistance behavior,and its wear mechanism is that the adhesive wear and abrasive wear coexist.