新型小直径端面CBN砂轮开发及其磨削性能研究

DEVELOPMENT OF NEW TYPE CUPCBN QUILL AND STUDY ON ITS FACEGRINDING PERFORMANCE

基于电镀小直径端面CBN砂轮磨削沟槽的试验结果,为减小沟槽底面与侧面过渡圆弧半径,开发了一种新型小直径端面CBN砂轮,在试验研究其磨削性能的基础上提出了改善措施,取得了良好的磨削效果。新型端面CBN砂轮加工沟槽的过渡圆弧半径达到0.2mm以下,比电镀CBN砂轮减小60%以上。新型端面CBN砂轮磨削过程中,由于有效CBN磨粒发生的后面磨损及其破碎,使磨粒切削刃凸出高度降低,而砂轮表面所有CBN磨粒均先后依次成为有效磨粒,因此提高单个CBN磨粒的耐磨性和韧性,减小破碎,是提高新型CBN砂轮寿命的有效措施。选用多晶强韧的CBN磨粒(通用电器GE550型产品)使砂轮寿命提高到了原来的6.75倍。

Based on the experimental results of grinding groove bottom using electroplated CBN cup quill, a new type cup CBN quill is developed in order to reduce corner radius betweengroove bottom and flank. According to experimental study on its grinding performance, improving measures are presented, and a good grinding result is obtained. As a result, the corner radius of new type cup CBN quill is less than 0.2 mm and remarkably less than one of electroplated cup CBN quill, the reduced factor is over 60%. It is discovered that flank wear on the effect CBN grain and subsequently the break of the CBN grain in the grinding process make reducing the protrusion height of effect grains, and all of the CBN grains on wheel surface become effect grains successively. Therefore, improving the wearability of CBN grain and heightening the toughness of CBN grain to reduce the break are effect measures to increase life of new type CBN quill. High-toughness polycrystalline CBN grains (GE 550 type) are chosen, it makes the life of new type CBN quill be increased by a factor of 6.75.