高压冷却下PCBN刀具切削高温合金切屑卷曲折断机理及试验研究

发布时间：2018-02-10 14:07

本文关键词： 高压冷却 PCBN刀具切屑折断高温合金　出处：《机械工程学报》2017年09期 　论文类型：期刊论文

【摘要】：高温合金广泛应用于航空航天领域,是一种典型的难加工材料,切削过程中切屑缠绕工件及刀具、不易折断,从而降低刀具寿命和已加工表面质量。PCBN是超硬刀具材料,加工高温合金等高温高强度钢性能优异,但由于刀具材料特性通常采用平前刀面,因此切削过程中断屑比较困难。高压冷却是金属高效切削加工中一种新型加工技术,可以有效改善断屑性能、提升断屑能力、提高刀具寿命和加工表面质量。目前对高压冷却断屑机理研究较少,且高压冷却切削仿真不易实现,为充分研究高压冷却下高温合金切削加工中的切屑折断机理,通过建立切屑卷曲半径预测模型和断屑模型,进行高压冷却下切屑折断机理研究,主要通过在高压冷却下,对PCBN刀具切削镍基高温合金进行试验研究,研究不同冷却液压力下切屑卷曲半径变化规律,对理论分析结果进行验证。研究结果表明:在高压冷却加工中由于高压冷却液的存在,切屑受到附加冷却液压力影响,使弯矩发生变化,造成切屑卷曲半径减小,最终导致切屑应变增大、切屑易于折断;且由于卷曲半径的改变使极限进给量和极限背吃刀量降低,使高压冷却加工改善断屑性能的效果非常明显。上述研究成果为实现高温合金高压冷却条件下的切削加工奠定了理论基础。
[Abstract]:High temperature alloy is widely used in aerospace field. It is a kind of typical difficult to be machined material. Chip winding workpiece and cutting tool is not easy to break in cutting process, thus reducing tool life and machined surface quality. PCBN is super hard tool material. High temperature and high strength steels such as superalloy have excellent properties, but the cutting tool materials are usually flat front face, so it is difficult to break chips in the cutting process. High pressure cooling is a new processing technology in metal high efficiency cutting. It can effectively improve chip breaking performance, improve chip breaking ability, improve tool life and machining surface quality. At present, there are few researches on the mechanism of high pressure cooling chip breaking, and the simulation of high pressure cooling cutting is not easy to realize. In order to fully study the chip breaking mechanism in high pressure cooling superalloy cutting, the chip breaking mechanism is studied by establishing the prediction model of chip crimp radius and chip breaking model, and the chip breaking mechanism is studied under high pressure cooling, mainly by means of high pressure cooling. The experimental study on cutting nickel base superalloy with PCBN cutter was carried out to study the variation of chip crimp radius under different coolant pressure. The theoretical analysis results are verified. The results show that the chip is affected by the additional coolant pressure in high pressure cooling process, which results in the change of bending moment and the decrease of chip crimp radius. As a result, the strain of chip increases and the chip is easily broken, and because of the change of crimp radius, the limit feed and the amount of knife are reduced. The effect of high pressure cooling process on improving chip breaking performance is very obvious. The above research results lay a theoretical foundation for the realization of high pressure cooling of superalloy cutting.
【作者单位】：哈尔滨理工大学机械动力工程学院;
【基金】：国家自然科学基金(51475128) 黑龙江省自然科学基金(E2016043)资助项目
【分类号】：TG132.3

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