Study On The Corrosion Behavior And Wear Resistance Of Ti₃AlC₂Ceramics

Recently, a series of excellent properties of the layered ternary ceramic Ti3AlC2attracts extensive attention. In this paper, we studied the chemical immersion andelectrochemical corrosion behavior of Ti3AlC2ceramics in different concentrated acidsolutions, and analyzed the corrosion mechanism. The wear resistance of Ti3AlC2ceramics was measured at room temperature and no lubrication oil on the material bythe pin-on-disc friction and wear test machine (УТИ TB-1000). The influence of slidingspeed, loading and friction pair materials on the friction coefficient and wear rate for theTi3AlC2ceramics were analyzed.The investigated results of the chemical immersion tests in different concentratedacid solutions indicate that, the corrosion behavior of Ti3AlC2in concentrated HNO3ismost serious and the mass loss is highest, the mass loss of Ti3AlC2in concentratedH2SO4is the slowest. The main reason is that intergranular corrosion and exfoliationcorrosion occur when Ti3AlC2is immersed in concentrated HNO3solution; whenTi3AlC2is immersed in concentrated H2SO4solution, pitting corrosion and intergranularcorrosion occur and passivation film forms on the surface of Ti3AlC2to prevent Ti3AlC2from corrosion.About the electrochemical corrosion of Ti3AlC2in different concentrated acidsolutions, the corrosion behavior of Ti3AlC2in concentrated HCl solution is mostserious. Pitting corrosion occurs on the surface of Ti3AlC2because of releasing Cl2. Thecorrosion mechanism in concentrated HCl solution is put forward combining with XRD,SEM and EDS: the Al in Ti3AlC2dissolves first, and then reacts with HCl to generateAlCl3.In wear resistance tests, GCr15as friction pair, the friction coefficient and wearrate of Ti3AlC2exhibit a decreasing tendency with increasing sliding speed; as the loadincreases, the friction coefficient and wear rate of Ti3AlC2exhibit increasing first, thendecreasing. The reason can be attributed to the oxide film, which covers on the frictionsurface of Ti3AlC2. The main abrasion to Ti3AlC2is the slight abrasive wear of wornsurface and slight scratch of the oxidation film. In wear resistance tests, Ti3AlC2as friction pair, adhesive wear occurs on the wornsurface of Ti3AlC2. The friction coefficient and wear rate are higher than which ofTi3AlC2against GCr15as friction pair.The large-scale Ti3AlC2ceramics prepared by SHS/PHIP has excellent corrosionresistance and excellent wear resistance, these excellent properties make Ti3AlC2acandidate material in many diverse applications.