多孔金属结合剂金刚石砂轮的制备及磨削机理的研究

发布时间：2018-01-03 22:33

本文关键词：多孔金属结合剂金刚石砂轮的制备及磨削机理的研究　出处：《河南工业大学》2016年硕士论文　论文类型：学位论文

【摘要】：金属结合剂金刚石砂轮强度高、耐磨性好、使用寿命长,广泛地应用于硬脆难加工材料如硬质合金、石材、陶瓷、玻璃等的磨削加工。但采用粉末冶金法制备的金属结合剂金刚石砂轮致密度高,磨削加工时自锐性较差、易堵塞、整形修锐困难,导致磨削效率下降。本文在金属结合剂金刚石砂轮中引入了孔隙结构,制备出多孔金属结合剂金刚石砂轮,使这类砂轮具有自锐性好、磨削力小、磨削温度低等优点。本文采用真空热压烧结法制备了铜基多孔金刚石砂轮。研究了低熔点Sn、Zn元素添加量对金属结合剂胎体的性能影响,当锡和锌含量总量固定为10%时,随着锡含量的增加,铜基结合剂胎体的抗弯强度从479.85MPa增加到701.82MPa,硬度从64.8HRB增加到99.8HRB,耐磨性逐渐增强。比较了两种造孔剂的造孔效果,在金相显微镜下观察了气孔的大小及分布状况,碳酸氢铵的造孔效果优于硬脂酸。制备出的金刚石节块的孔隙率在5.6%~39.99%之间变化,对应的抗弯强度在401.99MPa~58.7MPa之间变化。在扫描电镜下观察多孔金刚石节块断口微观组织形貌,建立了金刚石节块的断裂模型。在孔隙率低于20%时,金刚石与结合剂的结合界面是影响金刚石节块强度的主要因素,孔隙率超过30%后,孔隙成为金刚石节块强度的主要因素。对金刚石的预钎焊工艺作了初步探究,采用预钎焊金刚石做磨料能提高金刚石节块的强度。对硬脆材料磨削加工塑性去除和脆性断裂去除机理进行理论分析,指出采用多孔金属结合剂金刚石砂轮在硬脆材料延性域内磨削时的优势。在万能摩擦磨损试验机上磨削YG8硬质合金材料,多孔金属结合剂金刚石节块表现出了良好的自锐性,摩擦系数较低。当孔隙率在20%左右时,金刚石节块的磨削比达到最大。
[Abstract]:Metal bonded diamond grinding wheel with high strength, good abrasion resistance, long service life, widely used in machining hard brittle materials such as hard alloy, stone, ceramic, glass and other grinding. But the metal bonded diamond grinding wheel by the method of powder metallurgy high density, grinding self sharpening is poor, easy to plug, plastic dressing is difficult, resulting in grinding efficiency decreased. This paper introduces the pore structure in metal bonded diamond grinding wheel, preparation of porous metal bonded diamond grinding wheel, the grinding wheel has good self sharpening, grinding force, grinding temperature is low. The copper based porous diamond grinding wheel was fabricated by vacuum hot pressing sintering method. Study on the low melting point Sn, Zn element effect of addition on properties of metal bond matrix, when the total amount of tin and zinc content is fixed at 10%, with the increase of Sn content, the bending copper based bond matrix Strength increased from 479.85MPa to 701.82MPa, the hardness increases from 64.8HRB to 99.8HRB, the wear resistance increased gradually. Compared with two kinds of pore pore size distribution and porosity effect was observed under the microscope, the pore is better than stearic acid and ammonium hydrogen carbonate. The prepared diamond porosity changes in the range of 5.6%~39.99%, the flexural strength of the corresponding changes in the range of 401.99MPa~58.7MPa. To observe the porous diamond fracture microstructure under the scanning electron microscope, a fracture model of diamond segments. The porosity is lower than 20%, with the interface of diamond and matrix are the main factors influencing the strength of diamond segments, the porosity is more than 30% after the pore becomes the main factor of diamond segments. The strength of diamond pre ofbrazing operations made a preliminary inquiry, the pre brazed diamond abrasive can improve the diamond Festival The strength of hard and brittle materials grinding plastic removal and brittle fracture removal mechanism are analyzed in theory, it is pointed out that the porous metal bonded diamond grinding wheel in hard brittle ductile domain. The advantages of the friction and wear of grinding YG8 hard alloy material testing machine, porous metal bonded diamond segments showed self good sharp, low friction coefficient. When the porosity is about 20%, the grinding of diamond segments than the maximum.

【学位授予单位】：河南工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG743;TF125.6

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