新型金刚石纤维的制备及其切削性能

Study on Preparation and Cutting Performance of a New Diamond Grinding Fiber

采用添加一定量铁族金属Co的Na2O-Al2O3-B2O3-SiO2系陶瓷作为金刚石磨粒的陶瓷-金属结合剂,利用粉末注射成型和埋砂烧结法,设计制备一种具有一定长径比和宏观尺寸(1 mm×1 mm×10 mm)新型金刚石纤维,能按照使用要求进行有序排布,采用这种新型金刚石纤维替代传统金刚石磨粒能制备出有序化金刚石纤维砂轮。对金刚石纤维的抗折强度、硬度等性能进行测定,开展单根金刚石纤维试件与普通陶瓷砂轮加工超硬材料SiC增强高硅铝合金的对比试验。结果表明,制备的新型金刚石纤维具有一定的强度和硬度,其中的陶瓷-金属结合剂对作为切削主体的金刚石磨粒润湿性好、把持力强,金刚石磨粒不易脱落;新型金刚石纤维具有很好的加工性能,较之普通陶瓷砂轮加工工件表面质量更好,实现超硬材料SiC增强高硅铝合金的精密加工;新型金刚石纤维中,有效金刚石磨粒占有较高的百分比,分布较均匀,磨粒出刃等高性好,有效参与切削的磨粒数多,磨粒利用率高;新型金刚石纤维中,金刚石实现三维意义上的分布,即上层磨粒在磨耗磨损失去切削能力或在承受较大的摩擦和挤压力而脱落的情况下,下层磨粒得以出露继续发挥切削能力。

A new kind of diamond fiber with a certain length to diameter ratio and macroscopic dimensions（1mm× 1mm× 10mm）by powder injection molding and buried sand sintering method is designed and obtained.The new diamond fiber uses the Na2O-Al2O3-B2O3-SiO2 system ceramics adding a certain amount of iron group metal Co as the diamond abrasive ceramic-metal bond.Different from the traditional diamond grits,this new kind fiber has orderly arrangement in accordance with the requirements and can prepare ordered diamond fiber grinding wheel.Then the flexural strength,hardness and other properties of the diamond fiber are measured,and the contrast test between single diamond fiber specimen and normal ceramic wheel processed ultrahard material SiC enhanced high silicon aluminum alloy is conducted.The results shows that the new diamond fiber prepared has a certain strength and hardness; ceramic-metal bond in the new fiber gives better wet-ability and stronger holding force to the diamond abrasive particle and makes it difficult to fall off; meanwhile,the new diamond fiber has good processing performance and the workpiece has good surface quality,which can achieve precise machining SiC enhanced high silicon aluminum alloy.Effective diamond abrasive particles have a high percentage in the new diamond fibers,and the distribution is uniform.The abrasive particles have a good quality of high uniformity of protrusion height,and have a high utilization with large amount of abrasive particle participated in cutting.Diamond in the diamond fibers realizes three-dimensional arrangement,which means that the lower diamond can continue to play its cutting ability when the upper abrasive loses cutting ability or falls off due to bearing greater friction and extrusion pressure.