The aim of this investigation is to increase the corrosion and wear resistance of magnesium (Mg) alloys. This paper explains how various coatings applied via plasma powder (PTA) and laser deposition welding processes affect the wear properties of two Mg alloys. It is shown that coating quality depends on the type of Mg used, the composition of the filler materials (matrix and carbides), and welding parameters. The best results for Mg alloys AM50 and AZ31 were obtained with a coating consisting of a composite matrix (AlSi 12 ) with boron carbide additions. Paper text in German.

A new measurement technology in plasma spraying has been established at SULZER METCO AG, Switzerland. Based on the principle of C. Moreau, CNRC, it is now possible to simultaneously measure surface temperature and velocity of melted particles in a plasma flame. Since temperature and velocity are two of the most important parameters affecting coating characteristics in the thermal spray processes, the knowledge and control of these parameters offers new methods and assistance in the development of coating solutions. The object of this paper is to outline some important measurement results, to show correlations to splat formation and coating characteristics and to demonstrate applications in an industrial environment.

Dc plasma torches typically use a mixture of inert and molecular gases when spraying high melting powders. The addition of molecular gases increases the enthalpy of plasma jets, but it also produces arc root fluctuations that can cause variations in injected powders. This paper describes an innovative plasma torch system characterized by a long nozzle and three parallel cathodes. The nozzle consists of several electrically insulated rings and a ring-shaped anode. By adding more rings, the arc gap and voltage can be increased along with the enthalpy of the plasma jet. The results of various tests, comparing the spray rates and deposition efficiencies of new and conventional torches, are presented in the paper.

A new measurement technology in plasma spraying has been established at SULZER METCO AG, Switzerland. Based on the principle of C. Moreau, CNRC, it is now possible to measure surface temperature and velocity of melted particles during the flight in a plasma flame. Since temperature and velocity are two of the most important parameters for plasma spraying processes and coating characteristics, the knowledge and control of these parameters offers new methods and assistance in the development of coating solutions. The object of this paper is to outline some important measurement results, to show correlations to coating characteristics and to demonstrate measurement applications in an industrial environment.