Use of the small punch test for mechanical characterization of co– based laser cladding joint

Abstract

This work evaluates the capacity of the small punch test (SPT) to determine the mechanical properties of wear-resistant cobalt-based fabricated by laser cladding. The joint is made up of three zones: the cladding material, the interface, and the base material, each of which must be characterized individually. SPT specimens extracted from each zone were tested and the mechanical properties were obtained by using various correlations. The validity of these correlations was evaluated by comparing the properties obtained for the base and cladding metals with those obtained by standard tests. With this verification, the properties of the interface, which is a mixture of the base metal and the cladding, were extracted. The mechanical properties of the joint change with the hardness, which depends on the microstructure and the thermal distribution of the different zones. The results demonstrate the suitability of the SPT for characterizing layers of laser cladding, providing values similar to those obtained with tensile or fracture tests. The increase in strength and decrease in toughness in the interface and the cladding metal were in agreement with the microstructure in each zone.