自蔓延高温合成制备Ni3Si基复合涂层及其性能

摘要

The phase compositions and microstructures of Ni3Si-Cr7C3 and Nil7. 5Si29. 3Cr composite coating fabricated by self-propagating high temperature synthesis (SHS) technique were investigated. The results show that the matrix phases of the two composites are both the high temperature phase fj3-Ni3Si, and the adi-abatic temperature of the formation of Nil7. 5Si29. 3Cr coating is higher than that of Ni3Si-Cr7C3 coating. Therefore, the grain size of Nil7. 5Si29. 3Cr coating is smaller than that of Ni3Si-Cr7C3 coating, and Nil7. 5Si29. 3Cr coating has a higher microhardness. The tribological studies show that the wear mechanisms of the two composites are similar in dry friction and water lubrication. However, they are different in sulfuric acid solution, which is related to the different tribochemical reaction, and thus the Nil7. 5Si29. 3Cr coating has a better wear-resistant performance.%采用自蔓延高温合成法制备了Ni3Si-Cr7C3和Ni17.5Si29.3Cr两种Ni3Si基复合涂层,研究了两种涂层材料的相组成和微观结构.结果表明,两种涂层材料的基体相均为高温相β3-Ni3Si；同时由于后者具有更高的绝热温度,其晶粒尺寸显著小于前者,从而使Ni17.5Si29.3Cr合金涂层具有更高的显微硬度.摩擦学研究表明,两者在干摩擦和水润滑条件下的磨损机理相似,但是在硫酸溶液条件下由于发生了不同的摩擦化学反应,因此其磨损机理不同,后者具有更好的抗磨损性能.