金刚石珩磨磨石烧结变形的防止

加工内燃机气缸和活塞缸使用的各种金刚石珩磨磨石，尤其尺寸较大的珩磨磨石，经过热压烧结之后，会产生烧结变形废品。常见废品包括弯曲变形、裂纹以及分层现象。造成废品的根本原因，在于金刚石层与非金刚石层膨胀系数差别较大，两层材料热胀冷缩不一致。两层膨胀系数的差别，主要是因为金刚石膨胀系数远小于金属而造成的。解决问题方案是，往非金刚石层中添加廉价金刚石，或者添加与金刚石性能相近的碳化硅之类的填充料，从而缩小非金刚石层的膨胀系数，使之与金刚石层尽量一致。通过试验和生产验证表明，采取的措施是切实可行的，有效地解决了珩磨磨石的烧结变形问题。

Prevention of diamond honing sticks from sintering deformation

Diamond hones,especially bigger hones,used in grinding cylinders of internal-combustion engines and pistons are easy to bring deformation such as bending,cracks and lamination in hot forming and sintering processes.The reason is ultimately that there is remarkable difference in the expansion coefficient of the cutting layer and adhesive layer,since diamond's expansion coefficient is much less than metal binder's.The method of solving the problems is that cheap diamonds or fillers,whose performances are similar to diamond such as SiC,are added to the adhesive layer to reduce the difference of expansion coefficient of the two layers.The results of experiment and manufacture process indicate that the method of avoiding deformation of diamond honing sticks is feasible.