基于微喷砂射流技术的硬质合金刀片刃口钝化研究

刀具制造过程中的微观缺陷会降低刀具寿命,影响加工质量,而刃口钝化可有效消除刀具刃口缺陷。本文基于微喷砂技术对硬质合金刀片YT15进行全因素刃口钝化试验,研究了微喷砂工艺参数对刃口半径的影响以及微喷砂处理对刃口质量的影响,分析了微喷砂处理的材料去除机理。研究结果表明:微喷砂处理可有效钝化硬质合金刀片YT15刃口,改善刃口质量。     

硬质合金刀具磨料电解刃口钝化工艺试验

本文将磨料电解加工工艺应用到硬质合金刀具的刃口钝化中,并对钝化工艺方法做可行性实验研究。结果显示,新工艺可以实现刀具的刃口钝化,获得光滑的圆弧形刃口,切削刃得到明显改善。对于硬质合金刀具,磨料电解工艺的去除效率高于毛刷式钝化机2.3倍。     

硬质合金可转位刀片刃口振动钝化的研究

本文建立了振动钝化的力学模型。分析了振动体质点变振幅的李萨如图形[Lissajou's Figure]椭圆振动、圆周振动和相应质点速度分布,以及它们对钝化的影响。并从磨损方式和实验出发,讨论了控制电机转速、振幅、刀片装夹方式、磨料特性等因素来实现均匀性,完整性和高效率的硬质合金可转位刀片的刃口振动钝化方法。     

磨粒对刀具刃口钝化影响

为了研究磨粒对刃口钝化影响,介绍了钝化的实质及磨损的理论,然后用ABAQUS软件对单磨粒与刃口材料的作用进行仿真,结果表明刀具刃口的钝化是固体磨料以一定速度对刃口冲击所造成的材料损耗,影响刃口钝化的主要因素有磨料粒度、硬度、质量和速度等方面。     

YT15硬质合金刀片刃口电化学钝化实验研究

刀具是切削加工工艺系统的核心部分,刀具的耐用性和可靠性直接决定加工精度、表面质量和切削效率。为了改善硬质合金刀具切削性能,常需要对刀具进行刃口钝化。由于刀具为消耗品,其钝化技术需要具有加工一致性、高效率和良好的工艺适应性。本文采用电化学加工方法进行硬质合金刀片刃口钝化,实验结果发现,电化学钝化硬质合金刀片刃口可在短时间内获得接近30μm的钝圆半径,刃口均匀性良好,钝化后的刀片几何参数具有良好的一致性,对实际生产具有指导意义。     

硬质合金刀片刃口钝化及检测技术综述

阐述了硬质合金刀片刃口缺陷的产生原因和主要的刃口处理形式及其使用工况,总结当前主流刃口钝化技术及刃口检测的技术手段,提出刃口钝化检测技术薄弱是目前国内企业普遍存在的问题。由于对该技术重视程度普遍偏低,制约了我国工具行业品质提升,也制约了刃口钝化技术装备及工艺技术的发展。     

刃口钝化处理——可转位刀片自动化生产中的重要工艺环节

由于对可转位刀具不断提出更高的要求,所以可转位刀片切削刃的钝化工艺日益受到重视。为了经济地制造高质量的硬质合金可转位刀片,要求刃口钝化机在工件上下料和自动化程度方面,达到工业经济水平,并能采用优化的工艺参数,保证加工过程和钝化结果具有良好的置复性精度。本文介绍了能满足上述要求的新结构的刃口钝化机,提出了硬质合金可转位刀片集成制造的构想。     

硬质合金可转位刀片刃口钝化方法及刃口圆弧半径的测量

本文介绍了硬质合金可转位刀片刃口钝化方法——毛刷法,喷砂法,研磨和振动式钝化法。同时对刃口圆弧半径的测量进行了探讨。根据仪器设备条件分别采用投影放大法,光切法及轮廓放大法等几种方法对刃口圆弧半径进行测量。     

湿喷砂钝化技术对硬质合金刀片刃口K值影响规律性研究

硬质合金刀片需要通过刃口钝化来调整刀片刃口的微观形貌及切削强度,使用湿喷砂处理技术能有效地去除刃口存在的不同程度的氧化、微观缺陷并能形成一定的刃口形貌。文中分析了湿喷砂处理技术对硬质合金刀片刃口K值的影响规律,有利于控制K值的精度。选用未涂层的硬质合金刀片,设定湿喷砂的压力、角度和时间的三水平进行对比。通过对K值的变化情况分析得出:刃口K值随着湿喷砂的时间和湿喷砂的压力的增加先迅速增大后较缓慢减小;喷砂角度在湿喷砂压力小于0.3 MPa的范围内,随着喷砂角度的增加,刀片刃口K值呈不断增大的趋势;湿喷砂处理可通过裂纹延展而导致的脆性去除有效改善硬质合金刀片的刃口质量,消除微观锯齿或崩口。     

毛刷式数控钝化机在重型铣削刀片刃口钝化中的应用

简要介绍了可转位刀片刃口钝化的作用及型式.通过在BP-MX型毛刷式数控钝化机上进行钝化试验,确定了两种重型铣削刀片刃口的合理钝化参数,并分析了该机床的加工效率.     

硬质合金刀具刃口钝化方式对比试验研究

通过硬质合金刀具刃口钝化方式的试验研究,从钝化效率、钝化质量（刃口的均匀性）两个方面分析对比三种钝化方式（手工钝化、刀具在研磨粉中钝化、电解机械复合方式钝化）。从综合钝化效率以及钝化质量来看,钝化直线型刃VI的刀具采用电解机械复合方式钝化较好,解决了目前刃口钝化存在的均匀性不好的问题,对实际生产具有指导意义。     

三相射流去毛刺工艺的试验研究

金属切削毛刺是影响精密零件棱边质量及使用性能的主要因素之一。三相射流去毛刺技术是一种柔性工艺方法。三相射流去毛刺的作用过程和机理非常复杂,不仅与射流及作用条件有关,而且与材料的性质及毛刺的形状密切相关。通过正交试验,分析了三相射流工作条件对材料去除量和冲蚀深度的影响,讨论了磨料粒度与加工表面粗糙度的关系。     

船用螺旋桨砂带磨削研究

为改善船用螺旋桨叶片的磨削效果,采用两种不同磨料砂带对螺旋桨叶片进行了磨削试验。讨论了砂带线速度、法向磨削压力、磨料种类对材料去除率的影响;分析了砂带粒度和接触轮硬度对表面粗糙度的影响。试验表明:使用砂带磨削螺旋桨不仅可行,并且具有较高的材料去除率,可获得较小的加工表面粗糙度。该研究为确定合理的螺旋桨砂带磨削工艺参数提供了依据。     

磨料水射流对金属材料去除力和去除模型的研究

磨料水射流抛光技术作为一种新型技术,广泛应用于表面抛光加工作业中,利用含有细小磨料粒子的抛光液在高压作用下,与工件表面发生冲击、冲蚀而去除材料,以达到抛光目的。采用单颗粒磨料粒子使材料产生塑性变形模型来研究磨料水射流对金属材料的去除力,通过对纯水射流冲击材料的作用力和射流中磨料射流对材料的作用力以及接触应力的理论推导,得出磨料射流中轴线上磨料颗粒去除金属材料最大打击力和最大剪应力以及最大拉应力;通过建立伯努利方程,得到射流压力与金属材料的剪切力和拉应力的直接关系,为工程上磨料水射流抛光喷嘴设计和泵压选择提供了理论参考依据。     

磨料水射流抛光技术进展综述

磨料水射流抛光技术具有加工材料范围广、无热加工影响、能满足非线性与复杂曲面零件需要的高形状精度和高表面粗糙度要求等优势,在精密加工领域具有良好的研究价值和应用前景。首先对加工质量高敏感的工艺参数,如射流动能、喷嘴结构、磨料类型、加工路径等研究进行综述,总结了不同材料加工的工艺参数,分析了不同形状的去除函数加工的适用性;然后对磨料水射流与其他技术结合而衍生出的一系列新技术进行了总结,比较各种新技术的特点;最后对磨料水射流加工及其材料去除函数模型研究的发展趋势进行预测。     

PENETRATION ABILITY OF ABRASIVE WATERJETS IN CUTTING OF ALUMINUM-SILICON CARBIDE PARTICULATE METAL MATRIX COMPOSITES

This article presents a set of studies performed on aluminum-silicon carbide particulate metal matrix composites prepared by adding 5, 10, 15 and 20% of SiC in aluminum alloy and processed with abrasive water jets that are formed with garnet and silicon carbide abrasives of 80 mesh size. These studies are essentially meant to assess the penetration ability of abrasive water jets on different compositions of Al-SiC _p MMCs produced by stir casting method. Abrasive waterjet cutting experiments were conducted on trapezoidal shaped specimens of different composites as well on the constituent materials i.e., 100% aluminum alloy and 100% SiC specimens by varying water pressure, jet traverse speed and abrasive mass flow rate, each at three different levels. The percentage contribution of individual and combined effects of process parameters on penetration ability was analyzed by means of analysis of variance. Contribution of waterjet pressure and traverse speed on jet penetration in these meaterials are found to be more than abrasive flow rate. Among the interaction effects, waterjet pressure and jet traverse speed combinations contribute more to jet penetration. The results presented in this study can be used to build statistical models that can predict the depth of penetration of jet in different MMCs. This study also highlights the need to choose suitable abrasive mass flow rates and jet traverse speeds for effective processing of MMCs with abrasive water jets.     

The optimal cutting times of multipass abrasive water jet cutting

Cutting is one of the most important applications of abrasive water jet. However, there are always some quality defects in the cross section cut by abrasive water jet. It is found that multipass abrasive water jet cutting can effectively improve the cutting quality. In this paper, two types of multipass water jet cutting were summarized and redefined clearly first. Then, taking AISI 304 stainless steel as the workpiece, the cross sections after cutting with different cutting times were analyzed and compared with that after single cutting. The overall roughness and the overall taper of the section were obtained by a reasonable method. Besides, in order to give consideration to both the cutting quality and the processing time, the concept of quality improvement rate was put forward. On this basis, with the improvement rate as the index, the optimal cutting times for cutting AISI 304 stainless steel with multipass abrasive water jet were analyzed from two aspects of surface quality and kerf taper, and the optimal cutting times of cutting other materials by multipass abrasive water jet can be studied according to the same idea. The study of this paper provides important reference for the application of multipass abrasive water jet cutting.     

磨料液体射流抛光技术研究进展

论述了磨料液体射流抛光过程中的材料去除机理,介绍了磨料液体射流加工系统平台的国内外研究成果。从速度变化、材料去除、表面演化、表面粗糙度、数值模拟五个方面阐述了磨料液体射流数学模型的构建状况。系统分析了主要工艺参数如磨粒动能、射流压力、磨料、喷射角度、喷射距离、添加剂对加工结果的影响规律,并总结了磨料液体射流抛光技术发展历程。最后针对其将来的研究方向与内容给出了进一步的建议与展望。     

Experimental study of lapping and electropolishing of tungsten carbides

Lapping and electropolishing (EP) experiments for tungsten carbide blocks were executed. The effectiveness of the lapping experiment is evaluated in terms of the material removal rate, the surface roughness, and wear of the workpiece. The material removal rate describes the thickness removal of the workpiece under a fixed surface area. Wear describes a microscopic study of the wear track. The results show that the material removal and surface roughness increase as the grain size of the abrasive increases. Four main wear mechanisms -- abrasive wear, fracture, adhesive wear and scratch -- are observed during the lapping of tungsten carbide using silicon carbide abrasive. In the electropolishing experiment, four different machining characteristics -- sub-electropolishing, crack, electropolishing, and pitting -- can be analyzed as the applied current is increased. Although material removal is close to Faraday’s law during electropolishing, it disagrees with Faraday’s law after 400 s of sub-electropolishing.     

Numerical simulation for abrasive water jet machining based on ALE algorithm

In dealing with fluid impact and large deformation problems by traditional Lagrange grid, calculation failure often happens due to grid distortion. An abrasive water jet machining model is created to simulate the whole stage by software LS-DYNA from the jet into the nozzle to the workpiece material removal process using ALE (Arbitrary Lagrange–Euler) algorithm. The mesh for the abrasive and water is based on the ALE formulation, while the target mesh applies the Lagrange formulation. The effect of jet penetration is implemented by coupling the grids of ALE and Lagrange. The jet traverse speed is achieved by definition of the movement of ALE grid to reduce the mesh domain. The abrasive constitutive equations are also presented in this paper. The uniform mixture for abrasive and water is achieved by definition of volume percentage of the two materials in the initial ALE elements. Simulation results give the relationships between processing parameters and the cutting depth. The good agreement between simulation results and experimental data verifies the correctness of the simulation.