Microstructure, electrical and mechanical properties of Ti₂AlN MAX phase reinforced copper matrix composites processed by hot pressing

The copper (Cu) matrix composites have been constantly investigated to address the requirements for their utility in functional applications. Among the vast available reinforcements, the MAX phases are promissory to be efficient to strengthening the Cu, without a drastic reduction of its electrical conductivity. In the present report, the synthesis of novel Ti₂AlN MAX phase reinforced copper matrix composites (Cu-MAX composites) by using hot pressing are reported. The microstructure of the composites and the evidenced reaction between the matrix and reinforcement are discussed with the assessment of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). It was noticed that the diffusion of the Al and Ti atoms of the Ti₂AlN particles into the Cu matrix generated a microstructure composed of Cu, Cu (Al, Ti) solid solution and Ti-Cu-N particles with a nano-lamellar structure. The results of the mechanical, physical and electrical properties indicated that the density, hardness and flexural strength of the copper were influenced significantly with low amounts of reinforcement. The mechanical strength showed a substantial increment from 355 to 855 MPa while the ductility was maintained, by adding 5 wt% of Ti₂AlN into the Cu, whereas the electrical conductivity was reduced.