New Development Of Superhard Abrasive Grinding Technology

Abrasives made of diamond or CBN abrasives are called superhard abrasives. Because of its excellent grinding performance, it is now widely used in all aspects of grinding technology, and has become the basis of technological progress such as ultra-precision grinding, high-efficiency grinding, hard-to-process material grinding, high-precision forming grinding, grinding automation and unmanned.Diamond and CBN abrasives due to their complementarity in processing material adaptation, the range of abrasives composed of them can be greatly expanded, covering almost all of the materials processed, including a variety of high hardness, high brittilities, high strength and toughness materials.Diamond abrasive is the best grinding tool for hard and brittle materials such as cemented carbide, optical glass, ceramics and stone, but because it is easy to carbonize at 700 ° C ~800 ° C, it is not suitable for grinding steel materials and ultra-high-speed grinding. The emergence of CBN abrades leads to the best grinding technology, it can withstand the high temperature of 1300℃~1400℃, the chemical inertia of iron group elements, good thermal conductivity, high cutting rate of grinding steel, large grinding ratio, long abrasive life, is the best abrasive for grinding hardened steel, high-speed steel, high-strength steel, stainless steel and heat-resistant alloys and other metals with high hardness and toughness. In addition,CBN abrasive is also suitable for ultra-high speed grinding, metal matrix CBN abrasive line speed of more than 250m/s will not be broken.The widespread use of CBN abrasive mainly in recent years, a variety of high efficiency and high performance CNC grinding machine came out, as well as the progress of abrasive manufacturing technology, the development of new abrasive tools such as single layer plating and high temperature brazing with excellent performance, has promoted the development of grinding technology, especially the new process of high efficiency point grinding is more favored by people.Quickpoint Grinding (Quickpoint Grinding) is the first launched by the German Junker company. It is the use of brazed CBN thin grinding wheel (width only a few mm) and ultra-high grinding wheel line speed (120m/s~180m/s, up to 200m/s~250m/s) to achieve. When processing, the axis of the grinding wheel and the axis of the workpiece form a certain Angle of inclination in the horizontal direction, so that the theoretical line contact between the grinding wheel and the workpiece becomes point contact. In this way, the grinding contact area can be greatly reduced, and the extremely high grinding speed can not only thin the grinding chips, reduce the abrasive load, but also make the heat too late to pass to the workpiece and the grinding wheel, almost all are taken away by the grinding chips, improve the workpiece processing accuracy and surface quality. The use shows that the grinding ratio of the point grinding is large, the grinding wheel life is long, the dressing frequency is low, the material removal rate is high, and because it uses the same two-coordinate linkage as the NC lathe to achieve the surface grinding of complex rotary parts, a single installation can process the outer circle, cone, surface, thread, shoulder and groove and other shapes, which is more flexible than the cutting grinding, and the cooling effect is perfect. The grinding temperature is low, and even dry grinding can be realized. At present, the process has been used on the Santana car production line of Shanghai Volkswagen Automobile Co., LTD., and remarkable economic benefits have been achieved.