硬脆材料加工诱导崩边断裂的机理分析及控制方法研究

Study on the Mechanisms and Control Method of Edge Chipping Fracture in the Machining of Brittle and Hard Materials

硬脆材料加工过程中极易产生崩边断裂现象,会严重影响硬脆材料零件的质量,甚至会导致零件报废。通常采用调整加工参数减小切削力的方法来控制,但控制效果并不十分理想,反而会降低加工效率。本文通过对诱导崩边断裂机理的深入研究,构建出了对其影响因素的三层次分析模型,并提出了相应的控制方法。通过K9玻璃零件的加工验证了分析模型的合理性及控制方法的有效性。重点分析了硬脆材料钻孔过程中发生崩边断裂的形成机理,采用增加辅助支撑的方法来优化加工过程中工件的应力分布,探讨了增加辅助支撑需要注意的一些基本原则。最后,把此基本思想扩展到硬脆性材料复杂零件的加工中,取得了较好的效果。

Edge chipping fracture in machining of brittle and hard materials is easy to form. It could seriously affect the products quality and even would lead products below standard. The conventional control method is to decrease cutting force with lower machining parameters. But the control effect was not ideal. In this paper, the edge chip- ping fracture mechanisms in machining brittle and hard materials has been studied in depth, and a model with three levels of influencing factors was proposed. The rationality of the present model and the effectiveness of the control method were proved by machining a typical K9 glass part. The mechanisms of edge chipping fracture in drilling process of diamond cutter were analyzed selectively. The workpiece structure and cutting force distribution were changed by additional supports. Several basic principles of additional supports were discussed. Finally, the basic idea had been extended to machining complex parts of brittle materials and it worked well.