Synthesis of cubic boron nitride diffused-D2 steel surface composite by thermo-chemical diffusion process to enhance the wear resistance

Abstract

Abstract The diffusion of cubic boron nitride (c-BN) on the D2 tool steel surface was investigated using a thermo-chemical process in order to enhance the tribological properties of tool steel surfaces. The c-BN was diffused on the tool steel surface applying the thermochemical diffusion process using argon controlled furnace. The effect of temperature and soaking time on the diffusion process, micro-hardness, and wear resistance were the main parameters evaluated. The field-emission scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS) was used to analyze the morphology and elemental composition of the as-synthesized c-BN-D2 surface composite. Here, the micro-hardness of manufactured coatings was investigated using a Vickers hardness tester. The wear resistance of surface composite was studied using a pin-on-disk apparatus. The morphological investigation revealed that c-BN was successfully diffused in the surface of tool steel in the form of white globular precipitates. The best surface hardness produced has a values of 1570 GPa. The diffused layer thickness varies between 50–90 μm and is very dense. It has mechanical interlocking properties suitable against delamination process and wear formation. The superior performances of novel c-BN-D2 tool steel surface composite permits to extend the machine tool life, especially when is applied on the single-point cutting tools.