纳米硬质合金刀具切削Al/SiC_p复合材料的实验

针对SiC颗粒硬度高,切削Al/SiCp复合材料时刀具磨损剧烈,本文提出用具有较高硬度、韧性及良好抗磨损能力的WC-7Co制备纳米硬质合金刀具,并对Al/SiCp复合材料进行了切削实验。研究了纳米硬质合金刀具磨损机理和Al/SiCp复合材料的切屑去除机理,以及刀尖处后刀面磨损值。研究认为,纳米硬质合金刀具磨损的机理为SiC颗粒的微切削作用引起的磨料磨损,及SiC颗粒对刀尖刃口的高频、断续冲击引起的微崩刃及微破损;Al/SiCp复合材料的切削实质是断续切削;去除机理为切屑的崩碎去除;纳米硬质合金后刀面磨损值较普通硬质合金小30%～50%。实验表明,纳米硬质合金较普通硬质合金更适于加工Al/SiCp复合材料。

Experiments of cutting Al/SiC_p composite with nano cemented carbide tool

The tool can be worn seriously when Al/SiC_p composite is machined due to the SiC particles with a higher hardness. Based on the new nano-cemented carbide characterized by his high hardness,toughness,flexural strength and higher wear resisting property,a WC-7Co nano cemented carbide tool was prepared, and the cutting experiment was carried out.The wear mechanism of nano cemented carbide tool and chip removal mechanism were studied. Results show that the wear mechanism of nano cemented carbide tool is an abrasion wear due to the micro-cutting of SiC particles and the micro-chipping and micro-breakage of cutting edge caused by interrupted impact of the SiC particles under the high frequency. The essence of cutting Al/SiC_p is interrupted cutting,and the Al/SiC_p chip removal is the breakout of chip.Experiment indicates that the flank wear value of nano cemented carbide tool is about 30%-50% less than that of common cemented carbide,which means nano cemented carbide is more suitable for machining Al/SiC_p composite than common cemented carbides.