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利用超高压水射流切割试验系统,在80~280MPa压力范围内进行淹没磨料水射流切割试验研究,通过试验及数据分析,验证了后混合淹没磨料射流切割的可行性,得出了磨料粒径和质量流量、射流压力、靶距、切割横移速度等参数对射流切割性能的影响规律,对于脆性和塑性材料,试验中各参数对切割深度的影响基本一致.结果表明:在试验给出的工况条件下,磨料流量存在最佳值,在一定范围内切割深度随磨料流量增加而增加,当磨料流量达到一定值后,切割深度随流量增加反而下降;切割深度与射流压力基本呈线性增长关系;随着靶距的增大,切割深度逐渐减小;切割深度随切割速度的增加呈指数衰减趋势,并且相同试验工况下淹没射流切割深度要大于非淹没状态.试验结果为超高压淹没磨料水射流的实际应用和研究提供了参考. 相似文献
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将磨料浆体射流技术应用于切割领域,研制出相应的切割机床,避开了国外该项技术中的高压动密封问题,并对该机床的切割性能进行了正交试验,同时,将磨料浆体射流机床与前混合磨料水射流机床的切割性能进行了比较研究, 研究表明,影响磨料浆体射流切割性能的主要因素依次是切割速度、切割压力和靶距;在相同切割条件下,磨料浆体射流机床与前混合磨料水射流机床的切割力大致相同,但磨料浆体射流机床的切割质量明显好于后者,切割能耗大大低于后者。 相似文献
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根据工业性切割的需要,对磨料水射流(AWJ)切割机制进行实验研究。通过射流与材料之间的相互作用过程,建立和验证了AWJ切割过程模型,AWJ切割过程主要是通过磨粒对材料的周期性切割磨削和变形磨削完成;验证分析了典型材料的切割特征(切割深度、切口宽度、冲蚀量)与切割变量(水压、靶距、切速等)的关系,以及磨料、材质两大因素的影响。实验研究结果对AWJ切割技术的开发与应用具有指导意义和实用价值。 相似文献
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以切割质量研究为切入点,提出了前混合磨料水射流切割质量实验设计中工艺参数的选取与质量参数的选定、切割质量实验方案实施以及实验结果分析的方案。最后以水晶玻璃的切割实验为例介绍了前混合磨料水射流玻璃切割质量的研究。 相似文献
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横向超声振动对金刚石线锯切割硬脆材料锯切力及临界切削深度的影响 总被引:1,自引:1,他引:1
硬脆晶体材料,如SiC、Ge和Si等,由于其临界切削深度极小,常规加工方法很难实现塑性模式加工,研究横向超声振动金刚石线锯对硬脆材料锯切力和临界切削深度的影响有重要意义。在研究线锯受迫振动的基础上,分析金刚石线锯在横向超声波激励下柔性旋转点切割硬脆材料的条件;用特征函数对超声激励下金刚石线锯的振动切割状态进行表征;应用磨削理论建立了单颗金刚石磨粒切割硬脆材料的力学模型;推导出超声振动激励下金刚石线锯锯切硬脆材料临界切削深度的计算公式。以单晶SiC为对象,进行了超声振动线锯切割和普通线锯切割对比试验。结果表明相同条件下,超声振动线锯切割SiC的锯切力比普通线锯的锯切力减少22.4%~64.2%,临界切削深度增加1倍,晶片表面粗糙度有明显的改善。试验结果与理论分析具有良好的一致性。 相似文献
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石材锯切机理与金刚石工具磨损机理的研究现状 总被引:4,自引:0,他引:4
对金刚石工具切割石材等硬脆材料时的锯切机理、锯切过程中金刚石工具的磨损机理以及锯切力的国内外研究现状及各种观点进行了综合评述。由于石材等硬脆材料锯切过程的复杂性 ,对锯切机理的认识迄今尚不统一 ,对金刚石工具磨损机理和锯切力的理论研究也亟待深入。 相似文献
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Rotary ultrasonic machining of brittle materials, such as glass, ceramics, silicon, and sapphire, has been explored in a large number of experimental and theoretical investigations. Mechanistic models have been developed to predict the material removal rate or cutting force in the rotary ultrasonic machining of brittle materials. However, most merely describe the rotary ultrasonic machining process of drilling holes in brittle materials. There are no reports on the development of a cutting force model for flat surface rotary ultrasonic machining, i.e., rotary ultrasonic face milling. This paper presents a mathematical model for the cutting force in the rotary ultrasonic face milling of brittle materials under the assumption that brittle fracture removal is the primary mode of material removal. Verification experiments are conducted for the developed cutting force model and show that the trends of input variables for the cutting force agree well with the trends of the developed cutting force model. The developed cutting force model can be applied to evaluate the cutting force in the rotary ultrasonic face milling of brittle materials. 相似文献
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Brittle materials have been widely employed for industrial applications due to their excellent mechanical, optical, physical and chemical properties. But obtaining smooth and damage-free surface on brittle materials by traditional machining methods like grinding, lapping and polishing is very costly and extremely time consuming. Ductile mode cutting is a very promising way to achieve high quality and crack-free surfaces of brittle materials. Thus the study of ductile mode cutting of brittle materials has been attracting more and more efforts. This paper provides an overview of ductile mode cutting of brittle materials including ductile nature and plasticity of brittle materials, cutting mechanism, cutting characteristics, molecular dynamic simulation, critical undeformed chip thickness, brittle-ductile transition, subsurface damage, as well as a detailed discussion of ductile mode cutting enhancement. It is believed that ductile mode cutting of brittle materials could be achieved when both crack-free and no subsurface damage are obtained simultaneously. 相似文献
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以金刚石压头划刻BK7光学玻璃为研究对象,分析了脆性材料脆性去除过程中的声发射机制,研究了声发射信号的特征提取技术。多种切深实验显示:BK7光学玻璃发生脆性去除的特征主要集中在[100,200]kHz、[300,400]kHz两个频段,对应不同的声发射机制,其中[100,200]kHz频带的滤波信号呈现明显的、时间间歇的突发式声发射现象,与脆性材料裂纹的生成与扩展密切相关。基于上述实验结果,提出了以突发式声发射事件为单位的特征监测方法。针对该带通滤波信号的均方根值(RMS),研究了基于凸优化理论的声发射事件识别算法,得到了脆性材料裂纹扩展的时刻及能量信息。得到的结果表明:以声发射事件为单位的特征监测具有明确的物理意义,能够更加客观地表征脆性材料的去除过程。 相似文献
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岩石切削过程中破坏机制的离散元分析 总被引:1,自引:0,他引:1
利用离散单元方法(DEM)对两种不同属性的花岗石样本模型进行了切割模拟,通过调整不同的切削参数计算并分析了岩石切削过程中的切削力、切削深度、切削比能及切削力倾角的变化规律,从细观上探讨了临界切深对岩石脆性破坏模式和塑性破坏模式及其转变的影响,指出了当切削深度逐渐增大时,破坏模式依次从塑性破坏模式到过渡破坏模式最后转变为脆性破坏模式,同时切削力倾角并不随切削深度变化。将离散单元法分析的结果与实际实验进行了比较,表明该方法是合理的。 相似文献
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Characteristics of chip generation by ultrasonic vibration cutting with extremely low cutting velocity 总被引:3,自引:3,他引:0
Professor Jeong-Du Kim In-Hyu Choi 《The International Journal of Advanced Manufacturing Technology》1998,14(1):2-6
Recently, mirror-surface machining of brittle materials such as ferrite, glass, and optical plastics has become more important, as these materials are used in optical communications and precision devices. Non-ferrous metals such as aluminium and copper were readily turned with diamond tools, but as the need for both infra-red and reflective optics escalated, the need to machine brittle materials arose. In this paper, ultrasonic vibration cutting at 20 kHz at extremely low cutting velocity for the precision machining of brittle plastics used for optical lenses is suggested and tested. The mechanism of chip generation, and characteristics of surfaces in the ductile mode, machined by ultrasonic vibration cutting are investigated. As a result, when micro cutting by ultrasonic vibration, it was confirmed that the chips generated by ductile mode cutting are obtained at 1/40 of the critical cutting velocity of the ultrasonic vibration cutting system, which is an extremely low cutting velocity. 相似文献