Microstructural characterization and tribological behavior of surface plasma Zr-Er alloying on TC11 alloy

The Zr coating and Zr-Er coating are grown on TC11 substrate by double-glow plasma surface metallurgy technique, followed by the wear tests at ambient temperature and 500 degrees C. The data of nanohardness and elastic modulus of the samples are collected by the nano-indentation test. The adhesion strength of coatings is investigated by means of the scratch test. The study of wear resistance is performed using a ball-on-disc wear test system by running against the Si3N4 ball and measured by scanning electron microscope (SEM) and X-ray diffraction (XRD). Experimental results indicate that the nanohardness of the Zr coating and Zr-Er coating are 5.94 GPa and 7.98 GPa, respectively, which are 1.79 times and 2.41 times greater than that of TC11 substrate. Zr coating and Zr- Er coating realize the metallurgical bonding with TC11 substrate with continuous and compact structure. Compared with the Zr coating and TC11, the Zr- Er coating presents the lowest specific wear rates, which are 1.689. x 10(-6) mm (3) Nm(-1) and 1.851. x. 10(-6) mm(3) Nm(-1) at ambient temperature and 500 degrees C respectively, indicating the excellent and improved wear resistance of TC11.