用于陶瓷加工的金刚石磨具

介绍了金刚石磨具的结构，详细阐述了在陶瓷砖用烧结金属结合剂和树脂结合剂金刚石磨具制备中金刚石磨料的选择和应用，以及结合荆的种类和结合荆对金刚石磨轮性能的影响。     

普通磨具用陶瓷结合剂研究进展

本文简单介绍了烧结磨具用陶瓷结合剂:烧结结合剂、烧熔结合剂、低熔结合剂和磨具的低温烧成技术,对相关普通磨具陶瓷结合剂的研究文献进行了分析,阐明普通磨具陶瓷结合剂的发展方向在于促成磨具的低温绿色烧成和高强度高速砂轮技术。     

陶瓷结合剂cBN磨具的研究现状及发展趋势

陶瓷结合剂立方氮化硼(cBN)磨具的近年来研究越来越受到重视。简要介绍了国内外在陶瓷结合剂cBN磨具方面的最新成果。提出陶瓷结合剂目前研究的主要结构体系。讨论了陶瓷结合剂cBN磨具性能研究的方法和研究中存在的问题。最后指出陶瓷结合剂cBN磨具的发展方向。     

陶瓷结合剂对金刚石磨具把持力的影响及其研究进展

磨具主要由磨料、结合剂、气孔组成,其在使用过程中,磨料单位面积上受到的结合剂阻止磨料从磨具中脱落的作用力称之为把持力。如果结合剂对磨料的把持力不足,则会使磨料过早地脱落,导致磨具的寿命不足;如果结合剂对磨料的把持力过大,则造成磨具的自锐性较差。把持力在磨具磨削过程中具有非常重要的作用,其主要与结合剂的性能、磨料的表面状态等有关。对把持力的定义、分类以及影响因素进行了介绍,从陶瓷结合剂的性能、磨料的表面处理等方面综述了陶瓷结合剂对磨粒把持力的影响及其研究现状,介绍了把持力的表征方法并对未来的研究方向做了展望。     

陶瓷结合剂CBN磨具强度的影响因素研究

通过陶瓷结合剂本身强度、热膨胀系数与CBN(立方氮化硼)磨料的匹配性以及陶瓷结合剂CBN磨具的烧成温度等几方面对影响陶瓷结合剂CBN磨具强度的主要因素进行了探讨.研究结果表明:陶瓷结合剂的强度是影响CBN磨具强度的一个因素,但陶瓷结合剂本身强度的高低不是CBN磨具强度的唯一保证;结合剂与CBN磨料热膨胀系数的匹配性是影响CBN磨具强度的一个重要因素.通过实验发现,结合剂与CBN磨料的热膨胀系数之差应不大于5.2×10-6/℃;在一定烧结温度范围内,适当提高烧结温度,有利于提高结合剂桥相本身强度及结合剂与CBN磨料的结合强度.     

多孔陶瓷磨具的性能特点及研究进展

多孔陶瓷磨具是一类磨削效率高、磨削用途广泛的加工工具,通过详细介绍多孔陶瓷磨具的组成和微观结构,阐述了造孔剂的特点、不同造孔原理及造孔工艺对陶瓷多孔结合剂磨具性能的影响,分析了多孔陶瓷磨具的应用及国内外研究进展状况,并对多孔陶瓷磨具的未来发展做了展望。     

磨料表面镀覆对陶瓷结合剂超硬磨具强度的影响

在陶瓷结合剂超硬磨具的烧结过程中，超硬磨料易受到陶瓷结合剂中某些成分的腐蚀或受到热损伤，在超硬磨料表面涂覆一层保护层，既可减轻或避免腐蚀和热损伤，还可改善磨料与结合剂之间的结合状况。文章主要对各种镀层的金刚石、CBN磨料与陶瓷结合剂按一定的比例热压烧结进行了分析说明，并测定了其抗折强度，研究了各镀层对磨具抗折强度的影响。     

纳米陶瓷结合剂超硬磨具的制造工艺

纳米陶瓷结合剂是一种新型的超硬磨具结合剂,采用它能显著降低磨具烧结温度,大幅度提高制品的强度、韧性和耐磨性,且气孔可控,为陶瓷结合剂的应用开拓了一个崭新的领域.文章阐述了纳米陶瓷的性能及应用.结果表明:纳米陶瓷结合剂抗折强度高于100MPa,经过烧结,纳米陶瓷结合剂与金刚石和cBN超硬磨料润湿性良好、结合力大,在烧结过程中与超硬磨料不发生反应、不腐蚀损伤超硬磨料.成功用于磨削PCD复合片的金刚石陶瓷砂轮.     

碱金属氧化物Na2 O对陶瓷结合剂金刚石磨具性能的影响

通过调整陶瓷结合剂中碱金属氧化物Na₂O含量,来探究碱金属氧化物Na₂O对陶瓷结合剂金刚石磨具性能的影响。当n(Na₂O)/n(SiO₂)=0.1时,磨具试样的强度(57.7 MPa)和硬度(117 HRB)达到最大值。随着碱金属氧化物Na₂O添加量的增加,结合剂的耐火度随之显著降低,流动性显著增加。磨具试样断口SEM照片表明,适量的碱金属氧化物Na₂O能够使磨具断面空隙减少,孔隙度降低,结合剂与磨料分布更加均匀,结合剂与磨料结合界面更加紧密。XRD分析表明,磨具试样在720 ℃下烧结,结合剂中除了玻璃相还产生了一种晶相,结合剂中碱金属氧化物Na₂O的含量对烧结后产生的晶相种类无影响。     

PbO对陶瓷结合剂性能的影响研究

与其他结合剂相比,陶瓷结合剂具有散热好、易于排屑、成本低等优点,陶瓷结合剂在超硬材料磨具行业应用广泛。本文研究PbO对陶瓷结合剂性能的影响,通过向基础陶瓷结合剂中加入不同百分含量的PbO,对其耐火度进行了测定,利用微机差热膨胀仪、洛氏硬度计、微机控制电子万能试验机对加入不同量PbO结合剂的热膨胀系数和加入磨料后磨具的洛氏硬度和抗折强度进行了研究测试,再用体视显微镜对测过抗折强度的磨具试样进行断面观测分析。实验所得结果显示:适当加入少量添加剂PbO能显著降低结合剂的耐火度,加入超过10%或更多对其耐火度影响不大。与不加和加其它量相比,当添加剂添加量为5%时,加磨料后烧成的磨具具有较高的抗折强度和洛氏硬度;结合剂中加入添加剂PbO后,其热膨胀系数有所增大。通过体视显微镜断面观测可观察到,当加入PbO量过多时会有发泡产生。综合以上因素,PbO为陶瓷结合剂添加剂时,其添加量应控制在5%左右。     

微波烧结陶瓷结合剂金刚石砂轮研究

为了提高陶瓷结合剂金刚石砂轮的性能,采用微波烧结技术,通过一系列试验,分析了陶瓷结合剂金刚石砂轮的微波烧结温度、陶瓷结合剂含量和金刚石磨料粒度对其性能的影响。结果表明:微波烧结温度是影响陶瓷结合剂金刚石砂轮性能的最主要因素,远超其余二者;陶瓷结合剂金刚石砂轮试样的洛氏硬度和抗弯强度在740 ℃时达到极大值且气孔率较小,此时洛氏硬度为66 HRB,抗弯强度为76.5 MPa,气孔率为17.8%;由微观组织观察可知陶瓷结合剂金刚石砂轮在740 ℃时可以实现陶瓷结合剂对金刚石磨料的均匀包裹,并且气孔较少。     

Fabrication of New Porous Metal-Bonded Grinding Wheels by Hip Method and Machining Electronic Ceramics

Grinding wheels with different abrasive grains and different bonding materials were fabricated using hot isostatic press (HIP) sintering. Poly-crystal diamond powder of #1000 mesh size, single-crystal diamond powder of #1000 mesh size, and synthetic single-crystal diamond abrasive grains of #325 mesh size were used as abrasive grains. Cast-iron, and two different particle sizes of iron powders were used for the bonding material. The grinding capacity of these grinding wheels as well as conventional grinding wheels was evaluated by constant-pressure-grinding method to grind Al₂O₃-TiC component ceramics, which are typical electronic ceramics used for magnetic memory devices. The hardness of the bonding materials, the adhesion strength between abrasive diamond grains and the bonding materials, and the porosity of sintered body strongly relate to the grinding capacity. The porous bonded grinding wheels showed higher grinding capacity than the conventional wheels. The HIP method enables to fabricate excellent porous metal-bonded grinding wheels.     

Grinding of alumina ceramic with microtextured brazed diamond end grinding wheels

Brazed monolayer diamond grinding wheels have advantages of a high abrasive bonding strength, high protrusion, and a large chip disposal space. However, it is difficult to prepare ordered and fine-grained brazed diamond grinding wheels. This study presents a new method for grain-arranged, brazed diamond grinding wheels with microtextures with similar performance to ordered and fine-grained brazed diamond grinding wheels. First, coarse diamond grains (18/20 mesh) were orderly brazed to fabricate the end grinding wheels. Next, a series of microtextures were ablated on the diamond grains using a pulsed laser, and two types of textured end grinding wheels—TG-G (ablated microgrooves only) and TG-GH (ablated microgrooves and microholes)—were prepared. Then, an experiment involving the grinding of alumina ceramics was performed, and the grinding characteristics and grinding mechanism were analyzed. The results indicated that compared with untextured diamond end grinding wheels (TG), the textured diamond grinding wheels (TG-G and TG-GH) significantly reduced the grinding force and the roughness of the machined surface. The local stress concentration at the microtextures promoted the formation of microcracks in the diamond grains of TG-G and TG-GH, and the self-sharpness of the grinding wheel was significantly improved. The brittle fracture mode of ceramic materials in grinding included intergranular fracture and transgranular fracture. Ironing pressure action was a key material-removal mechanism. It had an important influence on the cutting force and plasticity characteristics of the TG machined surface. For the surfaces processed by TG-G and TG-GH, the effect of ironing was weakened, while shearing played a more important role. The TG-GH grinding wheel ablated with microgrooves and microholes was superior to the TG-G grinding wheel ablated with only microgrooves, with regard to the grinding force, roughness, and self-sharpening.     

聚酰亚胺与金刚石复合研磨膜的研制

根据软基体研磨膜的使用特点和聚酰亚胺的特性，研究聚酰亚胺与金刚石制作复合研磨的可能性。经试验确认，所制作的复合研磨膜符合使用要求，聚酰亚胺可以与金刚石磨料通过机械混合制作性能优良的复合研磨膜。这种复合膜的研制成功开拓了聚酰亚胺的又一应用领域。     

Fabrication of porous structure vitrified bond diamond grinding wheel via direct ink writing

Porous vitrified bond grinding wheels with complex structure, high porosity, controllable pore size have fundamental application in high efficiency and precision grinding of hard and brittle materials. In this paper, direct ink writing (DIW) is proposed to fabricate three kinds of grinding wheels, including solid structure, triangle structure, and lattice structure. Moreover, the rheological property of ceramic ink with different doses of xanthan gum (XG) solution was investigated to ensure printability, demonstrating 3% XG solution can meet requirements. Additionally, the effect of sintering temperature and pore former (PMMA) contents on size shrinkage rate, morphology, mechanical strength, and porosity et al. were studied. The results indicate that the diamond grinding wheel with 30 vol% PMMA and sintered at 670 °C possess the best comprehensive performance. Besides, grinding performance was evaluated by surface morphology, surface roughness, and material removal rate. Among the DIW-fabricated wheels, triangle structure grinding wheel and lattice structure grinding wheel possess a higher material removal rate than solid structure grinding wheel. Therefore, the porous structure grinding wheels fabricated by DIW present the advantage of controllable porosity, excellent self-sharpening ability, and higher bond strength, which may pave the way for designing a new generation vitrified bond diamond grinding wheel.     

砂轮用聚酰亚胺胶粘剂的研究现状

聚酰亚胺树脂是一种耐高温、高强度的工程塑料,它可用于制造金刚石砂轮,使砂轮的耐热性得到改善。本文从耐高温性、可加工性、高粘结性、耐磨性等方面概述了聚酰亚胺作为金刚石砂轮结合剂的优越性,实践证明,聚酰亚胺胶粘剂具有优异的耐热和高温粘接性能,用其制造的金刚石砂轮耐磨性优于酚醛砂轮。     

Effect of porosity on the grinding performance of vitrified bond diamond wheels for grinding PCD blades

In this paper, the preparation of nano-AlN modified Na₂O–B₂O₃–SiO₂ vitrified bond diamond tools with various porosities is reported. The effects of porosity on the impact strength and grinding properties of the wheels for grinding PCD blades are also discussed. The results show that the porosity not only affects the impact strength of the wheels but also the grinding properties, such as the grinding efficiency, the self-dressing, the service life and the surface roughness of the work pieces. The optimum porosity for nano-AlN modified Na₂O–B₂O₃–SiO₂ vitrified bond diamond wheels for grinding PCD tools is approximately 40.5 vol%.     

Grinding Temperature Measurements in Magnesia-Partially-Stabilized Zirconia Using Infrared Spectrometry

Results of temperature measurements by analysis of the thermal emission spectra generated during grinding and subsequently transmitted through partially stabilized zirconia workpieces are presented. Portions of emitted visible and near-infrared spectra were collected with spectrometers. Source temperatures were determined by fitting the scaled spectrometer output spectra to blackbody curves. Simulations showed that the effective temperatures determined by this method will be strongly biased toward hot-spot (flash) temperatures, which are expected to occur at the grinding grit–workpiece interface. Hot-spot temperatures on the order of 3000 K were obtained for grinding with both SiC and diamond wheels. These high temperatures modify the grinding process and the phase content of grinding chips.     

高岭土干粉磨过程的机械力化学变化

本文较全面系统地介绍了高岭土干粉磨过程中发生的机械力化学变化。采用粒度分析、SEM、XRD、IR、DTA和TG、反气相色谱(IGC)和BET多层吸附等测试方法对干粉磨高岭土进行分析测定。结合高岭石晶体结构特点,从机械力化学角度阐述了在高岭土干粉磨过程中发生的晶格无序化,脱羟基反应、表面性质改变以及团聚作用的机理。     

纳米陶瓷结合剂cBN砂轮的研究进展

文章综合论述了纳米陶瓷结合剂的性能特点、增强增韧机理以及研究进展,并探讨了纳米陶瓷结合剂cBN砂轮制备过程中存在的问题及对策,指出纳米陶瓷结合剂不仅可以解决目前陶瓷结合剂低熔点与高强度之间的矛盾,而且对于拓宽cBN砂轮的应用范围、适应超高速磨削技术具有十分重要的意义。