Study On Foaming Corrosion And Application Of Diamond By Iron-based Alloy Powder

Synthetic diamond powder possesses outstanding properties,such as superior hardness,superior strength,high wear resistance,and strong chemical inertness,thereby making them preferable as for ultraprecision machining and polishing.Given the small size of the diamond crystallites,binder materials are usually required to bond them together to form diamond tools.However,due to the smooth surface and few number of cutting edges,it is difficult to combine with the binder and easy to fall off during the preparation process of producing tools and the gringing surface is corse.In this paper,the surface of synthetic diamond powder was etched foaming by iron-based alloy and the diamond structre was refined and tend to be a micro/nano foaming feature.And then improve the bonding agent on the diamond holding force,so that the diamond through their own local broken to produce a new cutting edge,stabilize and maintain the sharpness of the tool to achieve efficient,high-quality processing.The main research contents and results were as follows:(1)The starting temperature of foaming corrosion of iron-based alloys to diamond is about 800?,and the corrosion of diamond increases with increasing temperature and holding time.When the mass ratio of diamond and iron-based alloys is 1:2,temperature 1000 ?,and holding time is 2h,the average particle diameter of the diamond D50 was reduced from 49.78?m to32.57?m,The surface area and pore volume were increased from the original 0.029m2/g and 0.000ml/g to 7.322m2/g and 0.012ml/g,respectively;When temperature is 1050?,insulation 2h,the diamond corrosion area and corrosion depth is the largest etched by low oxygen content iron-based alloy.At this time,the average diamond diameter D50 was reduced from 49.78?m to 33.01 ?m,and The surface area and pore volume were increased from the original 0.029m2/g and 0.000ml/g to 2.136m2/gand 0.007ml/grespectively(2)It appears to be three different corrosion pits on diamond surface:reversed pyramid-like etching pits with a punctiform bottom,ship corrosion groove with a linetape bottom,triangular or hexagonal ething with a smooth flat bottom correspond to {100},{110}and{111}plane of diamond.(3)The mechanism of diamond etching by iron-based alloy was:1)the iron and nickle atoms of iron-based alloy which contain unpaired electrons,prompt the carbon of diamond convert to grphite at high temperature.2)Fe2O3which comes from iron-based alloy and oxidized in the process of the molten alloy redox with diamond When the temperature is higher than 607?.(4)In the process of electrolytic purification of the diamond,the electrolysis efficiency of the cathode is related to the current density and pH.The increase of the cathode density increases first and then decreases with the increase of the current density.The optimum process for electrolysis is:current density of 10A/dm2,pH=5.(5)Compared to the as-recesived diamond,resin binder diamond abrasive grinding glass surface roughness from 0.873?m down to 0.363?m,the grinding efficiency of the resin-based diamond sintered body treated at 1000? was increased by 22.7%and the grinding ratio was reduced by 10.2%;The surface roughness of the glass after grinding with ceramic binder diamond abrasive was reduced from 0.977?m to 0.466?m,the grinding efficiency of ceramic-based diamond sintered body abrasive was increased by 21.0%and the grinding ratio decreased by 15.7%.