SiC_p/Al复合材料内螺纹螺旋磨削加工方法研究

Research on Helical Grinding of Internal Threads in SiC_p/Al MMCs

铝基碳化硅颗粒增强型复合材料(SiC_p/Al复合材料)切削加工性能较差,其内螺纹的切削加工难度更大。在研究SiC_p/Al复合材料磨削加工性能的基础上,提出利用电镀超硬磨料成形砂轮进行SiC_p/Al复合材料内螺纹螺旋磨削加工的工艺方法,并研制了电镀CBN成形砂轮,进行了具体的内螺纹磨削试验。试验结果验证了SiC_p/Al复合材料内螺纹螺旋磨削加工方法的可行性和灵活性。在砂轮线速度v_s=5.86m/s、进给速度v_f=80mm/min的条件下,CBN成形砂轮对SiC_p/Al复合材料展现出较好的磨削能力,单个砂轮可以完成17个M8螺纹孔的螺旋磨削加工,其内螺纹的加工尺寸精度均满足6H塞规的检测要求。同时,电镀CBN砂轮的磨损形式以磨粒磨损为主,砂轮表面未出现大面积脱落的现象。这说明,利用超硬磨料成形砂轮可以实现SiC_p/Al复合材料内螺纹的高效高质量加工,此工艺方法具有较高的工程应用价值,适于在实际生产中推广应用。

SiC particle reinforced aluminum metal matrix composite material （SiCp/Al MMCs） has a poor machin-ability, especially in the machining process of internal threads. Based on analyzing grinding machinability of SiCp/Al MMCs, the helical grinding method of internal threads with a super abrasive grinding wheel is developed and the helical grinding experiments are carried out utilizing an electroplated CBN grinding wheel. The experimental results show that the helical grinding method has the feasibility and fexibility. On the condition of grinding speed vs= 5.86m/s and feed rate vf= 80mm/min, CBN forming wheel presents an excellent grinding performance. A grinding wheel can fnish 17 internal threads （M8）, of which the quality meets the requirement of 6H thread plug gauge inspection. Meanwhile, the micro mor-phology of utilized grinding wheel shows that the wheel wear is mainly on the abrasive wear and only a few abrasive grains fall off from the wheel surface. All the experimental results indicate that the helical grinding method using the electroplated CBN wheel is effective in the machining internal threads of SiCp/Al MMCs with high machining effciency and surface quality. Thus, this grinding process has a great engineering application value.