Product Code: ICAL06_1002

Laser Cladding of Multiple Track Composite Nicrbsi Coatings
Authors:
Armando Yanez, Universidade da Coruna; Ferrol Spain
Jose Carlos Alvarez, Universidade da Coruña; Ferrol Spain
Jose Manuel Amado, Universidade da Coruña; Ferrol Spain
Maria Tobar, Universidade da Coruña; Ferrol Spain
Presented at ICALEO 2006

NiCrBSi coatings are employed to improve the quality of components submitted to high temperature wear and corrosion. Boron and silicon on its composition lowers the melting point and gives them its self-fluxing character. Hard ceramic particles like tungsten carbides (WC) can be added to increase hardness and abrasive wear resistance of the Ni alloy. WC has high hardness, certain plasticity and good wetting by molten metals. In this work, several mixtures of NiCrBSi alloy powder and a nickel-clad WC powder were laser cladded on steel (AISI 304). The aim was to determine the influence of the volume fraction of the reinforced WC particles on the performance of the composite layer. The effect of other treatment parameters, such as the laser energy, beam profile, traverse speed and the mass rate of the powder was investigated. Clad microhardness was measured and the microscopic morphology and distribution of WC particles within the layer characterized by scanning electron microscopy (SEM). Most clad layer properties are determined by the percentage of WC particles in the mixture. Below 50% WC content dense and crack free clad layers were obtained. Multiple clad tracks were deposited, with an overlapping factor of 40%, on preheated steel substrates to minimize cracks and pores formation. These coats were tested for friction wear using a pin on disk wear machine.