硬质合金枪钻毛坯的制造

硬质合金枪钻毛坯的制造李秀莲（陕西渭河精密工模具总厂,岐山７２２４０５）硬质合金枪钻是加工深孔用的切削工具,目前有着很好的销售市场。硬质合金枪钻由硬质合金毛坯和钢柄焊接后经机械加工制成。其规格多,形状复杂,毛坯的成形难度比较大。本文主要介绍规格从４５...     

YG6硬质合金电火花线切割加工工艺参数研究

采用高速走丝电火花线切割机床对YG6硬质合金进行切割加工实验,研究各电参数(脉冲宽度、脉冲间隙、峰值电流、间隙电压)对硬质合金切割加工速度和表面粗糙度的影响。硬质合金加工表面有许多凹坑,且随脉冲宽度和间隙电压的增加,凹坑更加明显。     

不同电极材料对电火花成型加工特性的实验研究

电火花成型加工过程中,不同的电极材料对成型工件的表面质量及加工时间均有影响,本文在相同的电参数与非电参数下分别以石墨、钨铜、紫铜3种工具电极材料来加工不锈钢工件并对实验的结果进行分析.实验结果发现:钨铜电极成型的工件表面质量最好,可以达到0.841um的高精度水平,满足航空航天精密零件的加工要求,同时加工时间为12.6...     

WC—20（Fe／Co／Ni）硬质合金断裂韧性的一种测定方法和断裂模式研究

用电火花加工的单边缺口试样，外推得到ＷＣ－２０（Ｆｅ／Ｃｏ／Ｎｉ）硬质合金的平面应变断裂韧性ＫＩＣ，发现表观裂纹扩展能量释放率ＣＱ（ρ）与试样缺口根部曲率半径ρ呈线性关系，即ＧＱ（ρ）＝ＧＩＣ＋Ａρ。在扫描电镜下观察断口形貌，认为有４种断裂模式：粘结相撕裂、ＷＣ晶闰解理断裂、ＷＣ－ＷＣ晶界开裂和ＷＣ－粘结相边界开裂，讨论了各种断裂模式的断裂过程。     

WC－20（Fe／Co／Ni）硬质合金断裂韧性的一种测定方法和断裂模式研究

用电火花加工的单边缺口试样，外推得到ＷＣ－２０（Ｆｅ／Ｃｏ／Ｎｉ）硬质合金的平面应变断裂韧性ＫＩｃ，发现表观裂纹扩展能量释放率ＧＱ（ρ）与试样缺口根部曲率半径ρ呈线性关系，即ＧＱ（ρ）＝ＧＩｃ＋Ａρ。在扫描电镜下观察断口形貌，认为有４种断裂模式：粘结相撕裂、ＷＣ晶粒解理断裂、ＷＣ－ＷＣ晶界开裂和ＷＣ－粘结相边界开裂，讨论了各种断裂模式的断裂过程。     

电火花强化技术应用

电火花强化技术是利用脉冲放电产生高温原理，将硬质合金材料熔渗到工模具及易损件的工作面上，形成一层高硬度、高强度、耐磨和耐温，又不剥离的硬质合金强化层。是一种新技术、新方法，有着广泛应用价值。据此，对其技术的应用进行了概述。     

硬质合金表面处理技术及其研究现状

硬质合金在相关行业中有着广泛的应用,常用作汽车、航空航天工业中加工金属部件的切削工具（车削、铣削、钻孔）,采矿领域中钻头和掘进机的部件,拉丝模具或冲床工具中的耐磨部件。硬质合金零件的失效主要在于其表面磨损,表面处理技术是解决硬质合金零件磨损问题的最有效方法之一。本文综述了近20年来硬质合金表面处理技术的研究进展,并从物理处理技术和化学处理技术两方面展开论述,系统地介绍了各种表面处理技术的定义、作用机理和效果,对不同表面技术进行了比较,并就硬质合金表面处理技术的发展进行了展望。     

浅谈加工模具中刀具材料的选用

分析了焊接切削用刀具在切削性能和加工精度方面的不足,比较了新型模具材料的优缺点,认为氮化硅系陶瓷刀具和碳化钛基硬质合金刀具。适合加工小型模具,而大型模具使用涂层硬质合金刀具较为合适。     

超声波对Ti-6AI-4V合金电火花加工特性的影响

钛合金是比强度高、耐蚀性、耐热性具佳的轻金属材料。在航空、汽车、深海潜水艇、生物体用材等方面有广泛应用。 然而,钛合金的导热率仅为铜的六十分之一,切削加工时易产生热量集中,导致工具磨损加剧,是典型的难切削加工材。 电火花加工时,工具电极与被加工物体不接触,故对材料的机械性能几乎没有影响。可作为难切削加工材料钛合金的加工     

一种基于参数绘图的H630楔横轧机模具CAD方法

介绍一种用ＡｕｔｏＣＡＤ二次开发工具进行Ｈ６３０楔横轧机模具设计的方法．这种模具ＣＡＤ（ＣｏｍｐｕｔｅｒＡｉｄｅｄＤｅｓｉｇｎ，计算机辅助设计）方法是一种基于参数绘图的方法，在输入主参数后，由计算机完成其他设计参数计算和参数自动绘图，并可根据需要选择模具不同的设计内容输出．     

Experimental Investigation and Optimization of Machining Process Parameters in AISI D2 Steel Under Conventional EDM and Cryogenically Cooled EDM Process

Electrical discharge machining (EDM) is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. In this research work, investigations were carried out on the machining of AISI D2 tool steel under conventional EDM and cryogenically cooled EDM process (CCEDM). The input process parameter such as current (I_p), pulse on time (T_on) and gap voltage (V) were investigated and the output responses like electrode wear ratio, metal removal rate and surface roughness were explored. Experiments were conducted using L₁₈ orthogonal array in EDM machine. Experimental results showed reductions in the electrode wear of 16% over CCEDM process. A grey relational analysis was used to solve the EDM process with multi performance characteristics to optimize EDM parameters.     

Hot Forging of C45 using PVD (Ti,Al)N/γ‐Al2O3 Coated Dies

The process of hot forging with permanent moulds is a challenge in respect to the very high thermal, mechanical and tribological loads on tools. Ensuring sufficient lifetime application of protective films can be beneficial. Initial screening experiments using PVD coated compression plates show that one of the metastable phases of alumina, the γ‐phase, exhibits high strength and toughness and fulfils the requirements for a protective coating. The next important step in the development towards an industrial application is the implementation on complex tool shapes and verification in real forming experiments. After coating deposition using an industrial coating unit, coated dies were tested in forming experiments under industrial conditions. The forming experiments show an improvement of the wear resistance after 1000 forming cycles for the coated dies compared to the uncoated dies.     

纳米氧化镧对电铸电极材料抗电蚀性的影响

增强工具电极材料的耐电蚀能力,降低电极损耗是微细电火花加工技术可靠、稳定且高效制造高深宽比微结构和器件的研究关键之一。选用纳米量级稀土氧化物-氧化镧为电铸基液添加剂制备了微工具铜电极材料,探讨了它的作用机理,分析了电铸铸层的微观形貌,并实验研究了纳米氧化镧添加剂对电铸电极材料抗电蚀性能的影响,优选了电沉积工艺参数。结果表明:添加适量纳米氧化镧添加剂并在适当电沉积条件下,电铸铜电极材料表现出较强的抗电蚀能力,且综合机械性能优异。     

两连式辊模拔制合金钢棒材理论与实践

通过实验分析了辊拔合金钢棒材的优缺点及其变形特点，运动学特点和力参数，指出辊模拔制合金钢棒材比辊拔丝更能发挥其优越性，并提出了辊模和固定模串联组合的新工艺。     

二连式辊模拔制合金钢棒线材实验研究

实验分析了辊拔合金钢棒材的优缺点及其变形特点，运动学特点与力参数。指出滚模拔制合金钢棒线材比滚模拔丝更能发挥出它的优越性，并提出了滚模和固定模串联组合的新工艺。     

A comparative study on the surface integrity of plastic mold steel due to electric discharge machining

The violent nature of the electric discharge machining (EDM) process leads to a unique structure on the surface of a machined part. In this study, the influence of electrode material and type of dielectric liquid on the surface integrity of plastic mold steel samples is investigated. The results have shown that regardless of the tool electrode and the dielectric liquid, the white layer is formed on machined surfaces. This layer is composed of cementite (Fe₃C) and martensite distributed in retained austenite matrix forming dendritic structures, due to rapid solidification of the molten metal, if carbon-based dielectric liquid is used. The intensity of cracking increases at high pulse durations and low pulse currents. Cracks on the EDM surfaces have been found to follow the pitting arrangements with closed loops and to cross perpendicularly with radial cracks and continue to propagate when another discharge takes place in the neighborhood. The amount of retained austenite phase and the intensity of microcracks have found to be much less in the white layer of the samples machined in de-ionized water dielectric liquid. The number of globule appendages attached to the surface increased when a carbon-based tool electrode material or a dielectric liquid was used during machining.     

Thermomechanical fatigue of dies for hot stamping

A method is proposed for calculating the fatigue life of dies used in hot stamping. Failure is assessed in terms of the strain and kinematic factors. Thermocyclic weakening is taken into account in determining the accumulated plastic strain. A special subprogram permits prediction of the number of cycles to die failure on the basis of finite-element modeling of tool–blank deformation.     

烧结高速钢及其应用

烧结致密法是制取高性能粉末冶金工具钢制品的一个途径。应用该工艺可获得基本致密,性能较高的粉末冶金工具钢材料。本文简述烧结高速钢制品的基本生产工艺及其性能。初步应用表明,它在切削工具、模具及耐磨件中的应用前景良好。     

Upsetting of a cylindrical blank by conical and flat dies. Part 1

The plastic flows of metal for the light stages in the upsetting of a cylindrical blank by conical and flat dies are considered. The position of the flows division is established at the boundary of two free surfaces at the end of the blank: the internal (conical) surface; and the external (lateral) surface. We may identify phenomenological aspects of the upsetting of a cylindrical blank by conical and flat dies: the direction of the displaced-metal flows; the curvature of the trajectory; the transition from sections that have no contact with the tool to end sections of the blank’s surface; the alternating rotation of the primary axes of the coordinate-grid cells; and the deformational rotation and shear near the end. The deformation due to the conical and flat dies is found to be superior to that associated with decrease in the contact friction and with the conversion of braking frictional forces to active forces. The theoretical conclusions are based on analysis of the same coordinate grid within the billet on the basis of nine photographs in step-by-step upsetting.