铝基复合材料搅拌摩擦加工制备工艺及其耐磨性能研究进展

Research Progress on Stirring Friction Processing Technology and Wear Resistance of Aluminum Matrix Composites

摘要:

铝基复合材料具有密度低、加工性能良好、耐腐蚀等特点，在高性能制造方面拥有举足轻重的地位，被广泛应用于航空航天、船舶机械等领域。然而，在往复运动的工况条件下，工件之间的磨损对材料的性能影响最为显著，从而降低工件的服役寿命。因此，提高工件耐磨性能和延长服役寿命，对于扩展铝合金的使用范围具有非常重要的意义。在制备铝基复合材料的工艺中，搅拌摩擦加工(Friction stir processing，FSP)技术是制备复合材料的新兴方式之一，所制备的复合材料具有优异的微观组织、不易产生界面反应等特点。所以，搅拌摩擦加工技术在铝基复合材料的生产中有巨大的应用潜力。针对搅拌摩擦加工制备铝基复合材料进行了综述，重点介绍了增强相的种类和含量，以及搅拌摩擦加工中的搅拌道次和焊接等参数，并且讨论了上述因素对铝基复合材料耐磨性能的影响。结果表明：随着增强相含量的增多，铝基复合材料的耐磨性能增强，但过多的含量反而会导致耐磨性能降低；随着搅拌道次的增加，有利于晶粒的细化，但是晶粒的细化程度过高，反而降低了铝基复合材料的耐磨性能。在此基础上，还研究了提高耐磨性能的机理。结果表明，在往复磨损过程中，材料的亚表层易形成动态再结晶，而动态再结晶尺寸对复合材料的耐磨性能有影响，过小的结晶尺寸会使耐磨性能下降。此外，还指出了搅拌摩擦加工制备铝基复合材料过程中存在的问题，如纳米增强相的团聚现象，以及选取适合FSP的工艺窗口等。最后，对FSP未来的研究趋势进行了展望。

Abstract:

Aluminum matrix composites has the characteristics of low density， good processing performance， and corrosion resistance， which are very important in high-performance manufacturing and widely used in fields such as aerospace and marine machinery. However， under the working conditions of reciprocating motion， the wear phenomenon between structural components has the most significant impact on the material， thereby reducing the service life of the workpiece. Therefore， improving the wear resistance of workpieces and extending their service life are of great significance for expanding the scope of use of aluminum alloys. In the process of preparing aluminum matrix composites， friction stirring processing （Friction Stir Processing， FSP） technology is one of the emerging ways of preparing composites， with excellent microstructure， not easy to produce interfacial reaction and other characteristics， which provides a huge potential in the production of aluminum matrix composites. A review of the preparation of aluminum matrix composites by FSP is conducted， focusing on the types and contents of reinforcing phases， as well as the number of stirring passes and welding parameters in FSP， and discussing the effects of the above factors on the wear-resistant properties of aluminum matrix composites. Among the factors of reinforcing phase content， the more the content leads to poorer wear resistance of aluminum matrix composites； the increase of stirring passes is conducive to grain refinement， but when the degree of grain refinement is higher， it reduces the wear resistance of aluminum matrix composites. On this basis， the mechanism to improve the wear resistance is studied. Finally， the future research trends such as the need to solve the problem of agglomeration of nanoscale reinforced phases in the preparation of aluminum matrix composites by FSP and the selection of suitable process windows for FSP are summarized and outlooked.