Heat Treatment Influence on Mechanical Properties of Nickel Based Cold Spray

Abstract

The article deals with evaluation of Ni and NiCr Cold Spray layers as a potential method for repairing components in energy industry by replacing or refilling flawed material. Cold spray layers from two NiCr powders of different particle sizes sprayed with nozzle for inner tube application and from Ni powder of one particle size sprayed with different nozzle types – for inner and outer tube applications – were tested. The evaluation is aimed on mechanical properties and metallographic analysis of cold spray layers as received and after defined heat treatments. It summarizes tensile properties at room temperature and microstructure of used powders and final cold spray layers. Ultimate tensile strength, hardness and plastic elongation are evaluated from the mechanical point of view. Metallographic analysis is focused on ovality and size of particles in powders and of splats in final cold sprays. Porosity of sprayed layers is evaluated on tested specimens.