Fabrication of nanostructured tool steel layer by combination of laser cladding and friction stir processing

A general fabrication process of the nanostructured tool steel layer with various carbide particles was developed by a combination of laser cladding and friction stir processing (FSP). The dendritic carbides formed by the laser cladding were crushed to carbide nanoparticles during the FSP, and were uniformly dispersed in the iron matrix. The shape and size of the carbide particles could be controlled by the conditions of the laser cladding and the FSP. The nanostructured tool steel layer formed by the laser and the FSP under the optimized conditions had a microhardness of ~ 900 HV which was higher than that of conventional tool steels.