In order to overcome the difficulties of laser melt injection (LMI) on aluminium alloys, the process of tungsten inert gas (TIG) arc enhanced LMI ceramic particles was developed. The influence of process parameters, including laser power, TIG current, the direction of powder feeding, the carrier gas flow of powder and the shield gas flow of TIG, was investigated. The results have shown that to achieve appropriate surface enhancement effect, the powder should be fed from the back side of the laser beam. The depth of the arc enhanced LMI layer increases monotonously with increasing TIG current. The depth of the LMI layer increases first and then decreases with increasing laser power. The carrier gas flow and gas flow of TIG should be matched. Through optimisation of process parameters, WCp/Al layer was prepared successfully on the surface of aluminium alloy. The microstructure of the surface layer prepared by arc enhanced LMI was analysed.

The whiskers with 2212 phase have been grown out by annealing a melt-quenched plate in a stream of gas at for 121 hours. Temperature dependences of the magnetic susceptibility (-T) and the critical current density have been measured. The transition point of the whiskers is 76.2 K, and the value is at 63.4 K, zero magnetic field. near is found, which hints that there may exist some inner grain Josephson junctions in the whisker.