摘   要:Fe-Al基金属化合物有着良好的抗氧化性和耐腐蚀性，并且它的密度小，成本低，因此它极有可能成为一种新型高温结构材料。近年来，围绕改善Fe3Al合金的室温脆性和低的断裂抗力的研究很多，然而，对以Fe-Al金属间化合物为基体的自润滑复合材料的研究较少。本论文主要研究了Fe-Al基自润滑复合材料的制备方法以及制得的复合材料的各方面性能，旨在加强对Fe-Al基自润滑复合材料的认识。

 本论文首先采用机械合金结合真空热压烧结制备了Fe3Al合金粉末，利用化学沉淀的方法制备出了Ba0.25Sr0.75SO4沉淀并置于干燥箱中烘干得到了它的固体粉末。然后将固体润滑剂粉末和合金粉末按照比例混合球磨后置于热压烧结炉中进行真空热压烧结，得到了Fe3Al-Ba0.25Sr0.75SO4自润滑复合材料。实验中主要研究了制备的Fe3Al-Ba0.25Sr0.75SO4自润滑复合材料的相组成，微观形貌，硬度，抗弯强度和抗压强度，以及真空环境下的摩擦磨损性能，并据此深入分析了复合材料的磨损和润滑机理。

 通过实验，发现制得的Fe3Al-Ba0.25Sr0.75SO4自润滑复合材料的硬度比Fe3Al合金的硬度低，但强度和韧性并没有很大的差距。除此以外，自润滑复合材料的摩擦磨损性能明显优于Fe3Al合金，固体润滑剂的加入极大地降低了材料的摩擦系数，且固体润滑剂的含量越高，摩擦系数越小。在滑动速度不变的真空环境下，随着载荷的增加Fe3Al合金的摩擦磨损率变化很大，且摩擦磨损系数都处于一个较高值，而自润滑复合材料的摩擦磨损率变化不大，摩擦磨损系数很低。

关键词：Fe-Al基金属化合物；固体润滑剂；自润滑复合材料；摩擦磨损

Abstract:Fe-Al intermetallic compounds have good oxidation resistance and corrosion resistance, and its density is low, low cost, so it is likely to become a new type of high temperature structural materials. In recent years, there have been many studies on room temperature brittleness and low fracture resistance of modified Fe3Al alloy.         However, there is little research on self-lubricating composites based on iron-aluminum intermetallics. In this paper, the preparation methods of Fe-Al metal self-lubricating composites and the properties of the composites were studied. The aim of this study was to further understand our Fe-Al metal-based self-lubricating composites.

In this paper, Fe3Al-based alloy powder was prepared by mechanical alloy and vacuum hot-pressing sintering. Ba0.25Sr0.75SO4 was prepared by chemical precipitation and dried in a drying oven to obtain its solid powder. Then, the solid lubricant powder and the alloy powder were mixed and ball milled in a hot-pressing sintering furnace under vacuum hot-pressing to obtain Fe3Al-based Ba0.25Sr0.75SO4 self-lubricating composite. In the experiment, the phase composition, microstructure, hardness, flexural strength and compressive strength of Fe3Al-based Ba0.25Sr0.75SO4 self-lubricating composites were studied, and the friction and wear properties of Fe3Al-based Ba0.25Sr0.75SO4 self-lubricating composites were studied. The wear and lubrication mechanism of the composites were analyzed according to the results.

Experiments show that the hardness of Fe3Al-Ba0.25Sr0.75SO4 self-lubricating composites is lower than that of Fe3Al alloy, but the strength and toughness are not very different. In addition, the friction and wear properties of self-lubricating composites are better than Fe3Al alloys. The addition of solid lubricants greatly reduces the friction coefficient of the materials, and the higher the content of solid lubricants, the smaller the coefficient of friction. In the vacuum environment with constant sliding speed, the friction and wear rate of Fe3Al varies greatly with the increase of load, and the friction and wear coefficient is at a high value, and the friction and wear rate of self-lubricating composite material is not changed, Coefficients are at a lower value.