陶瓷结合剂金刚石砂轮组织结构对其性能的影响

研究单晶硅片磨削用陶瓷结合剂金刚石砂轮的组织结构对砂轮性能的影响,评估砂轮组织结构对砂轮磨损速率、磨床主轴电流、磨削后的单晶硅片表面粗糙度及其表面形貌的影响。试验结果显示:主轴电流随着砂轮组织中孔隙率的增加呈现下降趋势,从最高的7.0 A降低至6.3 A;砂轮的磨损速率则表现出相反的规律,气孔率最大的砂轮的磨损速率是最小的砂轮的近2倍,分别为2.525 2 μm/片和1.423 8 μm/片;砂轮组织结构对磨削后工件的表面粗糙度影响不大,工件的表面粗糙度R_a值分别为7.67、7.47和7.37 nm;但当气孔孔径过大、孔壁变薄时,会造成磨削工件表面出现深划痕,导致硅片磨削质量恶化。      

特殊结构金刚石砂轮热压烧结工艺研究

本文设计了一种磨玻璃用新型特殊结构金刚石砂轮。采用正交设计和方差分析的方法研究了热压烧结温度、压力、时间对该砂轮性能的影响，并指出了在本实验条件下的最佳工艺参数。     

多气孔金刚石砂轮

本文报导了金属结合剂多气孔金刚石砂轮的研究成果，列出了砂轮配料组成、压制和烧结规范，研究了发泡荆对砂轮气孔尺寸的影响，还研究了通过气孔进给的润滑-冷却液的量对降低磨削区域温度的影响。     

特殊结构金刚石砂轮热压烧结工艺研究

本文设计了一种磨玻璃用新型特殊结构金刚石砂轮。采用正交设计和方差分析的方法研究了热压烧结温度、压力、时间对该砂轮性能的影响。并指出了在本实验条件下的最佳工艺参数。     

Na20含量对金刚石砂轮陶瓷结合剂性能的影响

研究了陶瓷结合剂中Na20的含量对陶瓷结合剂性能的影响。发现结合剂的耐火度随Na20含量的增加而降低；结合剂中Na20含量对由结合剂和金刚石磨料制得的力学试条的强度有很大影响，结合剂Na20含量较低时，随Na20含量的增加，力学试样抗弯强度提高。Na20／（B203＋Al203）的摩尔比为0．5时，试样的抗折强度最高为70MPa。同时，随Na20含量提高结合剂的膨胀系数增长，但Na20含量较低时膨胀系数增长较慢。实验结果表明通过改变Na20含量可以有效的调节金刚石用陶瓷结合剂的性能。     

树脂结合剂金刚石砂轮回收装置的研制

本文利用新研制的回收装置对树脂结合剂金刚石砂轮进行了回收试验，试验表明：此回收装置不仅可回收金刚石，而且也可同时回收铝基体，此项成果已被应用到几家企业的生产之中，并且得到了良好的经济效益，回收装置的研制使树脂结合剂金刚石砂轮的回收技术上升了一个新的台阶。     

不同无机铵盐对陶瓷结合剂CBN砂轮造孔的应用研究

分别研究了无机铵盐NH4F、NH4Cl、（NH4）2SO4和NH4HCO3的不同添加量对低温陶瓷结合剂CBN砂轮造孔的影响,采用气孔率、抗折强度以及试样SEM断口形貌对造孔效果进行了评价。结果表明：NH4Cl使砂轮开裂,不能作为低温陶瓷结合剂CBN造孔剂。NH4F造孔效果不明显,不适合造孔。（NH4）2SO4造孔剂的质量分数应控制在5％以内,质量分数达到5％时,砂轮孔隙率为36．14％,抗折强度为29．03MPa,气孔皆为小孔,气孔可调性差。NH。HCO,造孔剂质量分数应控制在15％以内,质量分数为5％时,砂轮孔隙率为34．19％,抗折强度为40．32MPa;质量分数增加到15％时,孔隙率达到42．5％,抗折强度为29．16MPa,且大孔径气孔比例随质量分数的提高而提高,气孔可调性好。     

Study on the grinding of advanced ceramics with slotted diamond wheels

Slotted diamond wheel grinding is a new machining technology. In this paper, an experimental study on the cutting force and the grinding temperature for ceramic face grinding using slotted diamond wheels is presented. Moreover, the empirical relationships related with the material removal rate, the surface roughness, the depth of cut, the wheel speed and the grain size are discussed. With these relationships, a temperature field for face grinding has been built. The work contributes to the fundamental theories for optimal design of slotted diamond wheels.     

MgO/SiO_2摩尔比对金刚石砂轮用陶瓷结合剂性能的影响

研究了Na-B-Al-Si-O系陶瓷结合剂中MgO/SiO2摩尔比对其性能的影响。研究表明,随着MgO/SiO2摩尔比从0.09增加到0.35,结合剂的耐火度从800℃降低到725℃,热膨胀系数先减小后增大,但MgO的加入能有效控制结合剂热膨胀系数只在小范围内变化。制备的砂轮试样抗折强度最高值达到95MPa,利用所研究的结合剂制备的砂轮比市售砂轮使用寿命提高25%。研究结果证明:减少碱金属氧化物含量、增大碱土金属氧化物含量是获得低耐火度、低热膨胀系数结合剂的一种有效方法。     

烧结方式对陶瓷结合剂金刚石磨具性能影响的研究

本文采用低熔点的陶瓷结合剂制备金刚石磨具,研究不同烧结方式及烧成温度对磨具的弯曲强度、硬度及磨削性能等的影响,同时研究不同温度下不被包裹金刚石及被玻璃粉包裹金刚石的热失重率.通过研究发现:725℃时,不被包裹金刚石的热失重率为5.47%,玻璃粉包裹后金刚石的热失重率仅为1.27%;制备的陶瓷结合剂金刚石磨具在725℃下烧成时,埋砂烧成磨具试样的弯曲强度和洛氏硬度值比不埋砂烧成时分别提高了2.7%和1.5%;埋砂烧成比不埋砂烧成磨具的使用寿命延长10.4%～15.9%,但磨具加工一片刀具用时延长约20%,磨削过程需要砂轮修整.     

磨PCD刀具陶瓷结合剂金刚石砂轮的研究

本文研究制备Na2O-B203-Si02-Al203多元系基玻璃料,并配制成低温陶瓷结合剂,研究发现:耐火度为685℃,流动性为110%～130%,线膨胀系数为5.35×10-6℃-1的低温陶瓷结合剂具有优异的性能.制备的陶瓷结合剂金刚石砂轮在725℃烧成后,磨具的抗弯强度和洛氏硬度达到最佳值,分别58.61 MPa和77.9.用其磨削PCD刀片时锋利性好,磨削中间不需修整,砂轮耐用度高.运用扫描电子显微镜(SEM)分析了陶瓷结合剂金刚石磨具的断面形貌、磨削后磨削面形貌,表明结合剂对磨粒黏结牢固,断面组织均匀.     

Wear of diamond dresser in laser assisted truing and dressing of vitrified CBN wheels

The rapid wear of diamond dressers in truing and dressing of vitrified CBN wheels remains an unsolved problem, and significantly affects the grinding performance of dressed wheels. Through combining laser-induced thermal effects into the process, laser assisted truing and dressing opened a new avenue for reducing the wear rates of diamond dressers. In this study a systematical investigation on the wear properties of diamond dressers in the novel laser assisted truing and dressing has been conducted, including (1) a theoretical analysis of some underlying items in the process of laser irradiation, (2) an experimental investigation of wear rates in the laser assisted truing and dressing, and (3) influences of the HAZ (heat affected zone) left by the last pass of laser assisted dressing. Experimental results show that the wear ratios of diamond dressers in the laser assisted dressing depend on laser power, depth of cut, and feed rate. Moreover, the heating history also has some impact on the wear ratios of diamond dressers.     

磨PCD刀具用陶瓷结合剂金刚石砂轮的研制

以Li2O-Al2O3-SiO2-B2O3系作为基础玻璃,设计了两种不同化学组成的结合剂(V1和V2)。采用三点弯曲法,考察了两种结合剂试样的抗折强度随烧结温度的变化规律,以及结合剂引入量对含金刚石试样抗折强度的影响;借助XRD衍射分析技术测试了结合剂试样条的物相构成;分别用两种结合剂制作了陶瓷结合剂金刚石砂轮,考察了在不同磨削条件下的磨削效果。实验结果表明:V1结合剂为玻璃质结合剂,V2结合剂为微晶玻璃质结合剂;采用V1结合剂制作的金刚石砂轮比采用V2结合剂制作的金刚石砂轮性能更佳,可用于PCD/PCBN复合片的粗磨加工。     

Comparison between vitrified bond and resin bond diamond grinding wheel in grinding PDC

In this research, the advantages and disadvantages of the cylindrical grinding process of Polycrystalline Diamond Compacts (short for PDC) with vitrified and resin bond diamond grinding wheel are compared. The research results show that the vitrified bond diamond grinding wheels, which use Ti-coated diamond grains as abrasive and glass ceramic as bond, have many advantages in grinding PDC . Compared with resin diamond grinding wheel,vitrified bond wheels lead to 35% grinding cost reduced, 40% grinding time of each PDC saved, and the size precision of PDC improved (from ±0.03mm to ±0.01mm). When grinding feed is ＜0.10 mm, the grinding ratio increases with increased grinding feed. However, when the grinding feed exceeds 0.10 mm, the grinding radio decreases rapidly with the increasing of grinding feed. The disadvantage of this kind of grinding wheel is that the brightness of the ground PDC cylinder is not as shining as that processed by resin bond diamond grinding wheel.     

Laser surface preparation of vitrified grinding wheels

A new method for surface cleaning loaded grinding wheels is introduced by applying CO₂ laser irradiation onto the grinding wheel surface. It was demonstrated that effective cleaning can be achieved by selection of the laser power flux and the duration of the irradiation. Fusion and evaporation of clogged metal chips play important roles in the laser cleaning process. It is suggested that high laser power irradiance and short irradiation duration are essential for effective grinding wheel cleaning. This paper was presented at the fourth International Surface Engineering Congress and Exposition held August 1–3, 2005 in St. Paul, MN.