Laser Sintering of Abrasive Layers with Inclusions of Cubic Boron Nitride Grains

Abstract

One of the mainstream technologies for industrial tools manufacturing is the high-speed local heating technique that drastically increases the productivity of tools manufacturing. With further optimization of sintering processes, it is possible to manufacture industrial processing tools with high density and relatively small grain size. The use of a focused laser beam as a heating source also contributes significantly to the increase in productivity of tool manufacturing and broadens the range of bonding materials that could be used to form the Cubic boron nitride (CBN) containing abrasive layers. The research is mainly focused on the irradiation of CBN grains with lasers of two different wavelengths - λ = 1.06 μm and λ = 10.6 μm. Technological parameters of laser processing were as follows: Laser power P – 200 - 700 W, focal spot diameter d – 3 mm, processing speed V – 0.01 - 2.0 m/min. The density of CBN grains was measured before and after laser irradiation using DA-2 measuring unit according to standard procedure. Bronze and Nickel powders (BrО10 and PS-12 N-WC) were used as a bonding material. They were mixed with CBN grains and were applied onto the steel base plates followed by laser irradiation of the prepacked layer. Scanning electron microscopy (SEM) was used to investigate the microstructure of samples along with local and integral X-ray element analysis. Microhardness of irradiated samples was measured as well. The interaction of laser beam and CBN grains was studied in detail and relationships between key technological parameters and quality of composites (grains durability, wear resistance and bonding strength) was established.