Study of the interfacial reaction between Ti3SiC2 particles and Al matrix

MAX phases have a unique laminated ternary structure and excellent self-lubricating properties. Their tribological properties are similar to that of graphite in addition to having excellent high-temperature oxidation resistance. Because of these features, MAX is an ideal external reinforcement for metal-based self-lubricating composites. Here, Ti3SiC2 powder and pure aluminum (Al) powder were combined as the raw materials to prepare Ti3SiC2/Al-based composite without significant interface reaction between particles and matrix using spark plasma sintering. The degree of relative density of the composite was estimated to be as high as 96.6%. The features of the interfacial reaction between Ti3SiC2 and Al matrix were studied over varying times of isothermal treatment. The results showed that the holding temperature was the key factor in the initiation of the interfacial reaction. No interfacial reaction was observed when the reaction was conducted at 500 degrees C/10 h. At a holding temperature of 600 degrees C, the Si atoms in Ti3SiC2 entered the matrix to form Al(Si) solid solution. Ti then bound to both Al and C to form Al3Ti and TiC. Varying the holding time had a significant impact on the morphology of the reaction products. At temperatures below 700 degrees C, prolongation of the holding time caused particles to gradually eVolve from irregular to lath-shaped. Ti3SiC2 completely decomposed at holding times of 10 h. The performance of the material also changed throughout the process of thermal treatment. As the holding time was prolonged, the density of the material continuously decreased, while the hardness first increased and then decreased. The coefficient of friction and degree of wear first decreased and then increased. The minimum coefficient of friction and wear were 0.23 and 0.01 x 10(-2) g, respectively. (c) 2017 Elsevier B.V. All rights reserved.