Papers by Keyword: Metal Bond

Abstract: There is the grade as one of the selection criteria of a grinding wheel like WA whetstone or GC whetstone. The grade of grinding wheel is defined as an index which shows the strength of connection of a grain and a grain, and is usually estimated by bending strength. There are many papers about the relationship between the grade of a grinding wheel and the grinding performance. And, the relationship between the grade of a grinding wheel and the grinding performance is almost clear. Also, the relationship between mechanical properties of a grinding wheel and the grade is also clear. On the other hand, since the grain layer of a super abrasive grinding wheel is thin, it is difficult to apply the conventional evaluation test of the grade. And, the evaluation method of the grade which can be adapted the super abrasive grinding wheel is not established. In addition, since the grade of a super abrasive grinding wheel is a manufacture manufacturer's original standard, there is a minute difference by manufacturer. The super abrasive grinding wheel as well as the grinding wheel is conjectured that the grade influences the grinding performance. Namely, it is important to relate the grade and the mechanical properties of a grain layer. However, researches which relate the grade, the grinding performance and the mechanical properties of a super abrasive grinding wheel are not done so far. Therefore, this study examined the relationship between the mechanical properties of a grain layer of a super abrasive grinding wheel and the grade, the grinding performance. The final objective of this study is to evaluate the grinding performance from mechanical properties of a grain layer of a super abrasive grinding wheel. The purpose of this report is to clarify relationship between the grade and the grinding force in a resinoid bond diamond wheel. The specific experiment procedure is as follows. When carrying out surface grinding of the diamond sticks using a grinding wheel, the relationship of the grade and the grinding force was clarified. And based on the knowledge acquired in this experiment, relationship between the grade of a super abrasive grinding wheel and the grinding force was considered. As the results, it confirmed that the grade of a resinoid bond diamond wheel could be evaluated by the grinding force.

Abstract: The article considers the problem of diamond disk efficiency when processing hard-alloy materials. Special attention is paid to the composition of greasy layer and mechanism of protective membrane formation on the surface of diamond disks. It is known that there are possibilities for blocking greasy layer and increasing cutting properties of metal-bonded diamond disks when polishing hard alloys.

Abstract: Effect of the pore size and volume fraction of alumina bubbles on the mechanical properties and microstructure of metal bond for superabrasive grinding wheels were studied by means of single factor test. The results showed that the mechanical strength reduced with the increase of bubble size and volume fraction of alumina bubbles. The morphology of the center section of the binder matrix showed that the higher the volume fraction of alumina bubbles was the less the effective area rate of the matrix was. Additionally, the bigger the bubble size was the more inhomogeneous the bubbles distributed. The pores generated after the fracture of the alumina bubbles had a regular shape and size which satisfied the chip space requirement of the wheels. At last, the failure condition of the bond matrix was established, which indicated that the strength of the bond matrix is mainly related to the effective area rate and the homogeneity of the bubble distribution.

Abstract: The results of investigation in order to increase the efficiency of using diamond-abrasive and edge tool made of superhard materials (SHM) on the basis of 3D methodology of complex research of the interrelated processes of their manufacturing and operation are presented. Creation of 3D simulation methodology of processes of sintering of abrasive-diamond tools and processes of grinding of edge SHM tools with their application allows us to increase considerably the reliability of obtained results, to reduce the extent of experimental studies for determination of optimum conditions for grinding and to develop new technologies, tools and equipment. The scientific hypothesis about the expediency of using diamond powders with thick metal coatings in diamond-abrasive tools on metal bonds are proposed and proved on the basis of theoretical research. The research results are implemented as a number of grinding techniques with controllable cutting relief of the wheels and devices which realize them. Using the results of the research makes it possible to increase the reliability of the edged tool made of SHM as far back as at the stage of its sharpening.

Abstract: As demand for high-quality machined tools considerably grows, ELID, a new and efficient technology, has been successfully brought into the precise manufacturing industry of hard and brittle materials with mirror surface finish. Hence, besides conventional functions like lubrication, fluid solutions in this grinding process are required to serve more functions, especially as electrolyte. Writers of this paper mainly work on the methodology to optimize this kind of fluid by adding various related chemical additives. By varying the pH, the accretion of additives is controlled and consequential effects are studied which is the metallic oxide layer variation before and after each test. Corresponding experiments have been carried out with procedures and results analysis included in the paper.

Abstract: Laser processing of super-abrasive grinding wheel is paying a role in a truing/dressing technique to complement mechanical methods recently. However, normal dressing/truing is difficult owing to the toughness of metal-bond materials and high hardness of diamond abrasive. Both geometric and mathematic models were developed to improve laser processing quality and predict various processing parameters, such as focal offset, and incident power, and power density to perform material removal during laser processing a metal-bond diamond grinding wheel. Various trends of the geometrical features of dressing zone in terms of the varying focal offsets were analyzed. Discussions were also given on dressing-zone geometry control. Experimental studies were carried out using different processing parameters to test the effects of laser poweres on dressing quality. Further grinding-force measurement determined the laser dressing parameters with respect to the wheel surface conditions. The normal force FN reduces up to 20%, while tangential force FT decreases to 7% too.The outcomes were shown well agreement with predicted results.

Abstract: The present study was undertaken to examine the effects of rare earth (RE) in hot pressing of Cu-Sn-TiH2-bonded diamond composites. Two kinds of composite specimens – with RE and without RE – were fabricated. As an additive to the Cu-Sn-TiH2 bond matrix, the RE was used in the form of misch-metal. The hardness and transverse rupture strength (TRS) of the specimens were measured. SEM and EDS were used to analyze the fracture surfaces of the specimens. Both hardness and TRS of the specimens with RE were found to be higher than the specimens without RE. SEM observations indicated that the pop-outs of diamonds on the fracture surface of the segments without RE are more than the specimens with RE. But more diamonds were fractured on the fracture surface of the segments with RE.

Abstract: In V-groove ELID grinding process, to achieve optimal grinding performance and satisfactory surface quality and profile accuracy, metal bonded diamond grinding wheels need to be carefully sharpened. In this paper, we applied the proposed new micro-truing method consisting of electro-discharge truing and electrolysis-assisted mechanical truing to sharpen the edge of large grinding wheels. The minimum wheel tip radiuses of 6.3 and 8.5µm were achieved for the #4000 and #20000 grinding wheels. The truing mechanisms and sharpening performance are also discussed.

Abstract: Metal bonded diamond grinding wheels are widely used in the grinding process, especial in ELID grinding. However, truing is difficult owing to the high toughness of metal bond materials and high hardness of diamond abrasives. To realize high precision and high-efficiency truing, we propose a new micro-truing method consisting of electro-discharge truing and electrolysis-assisted mechanical truing in this paper. The process principle and fundamental experimental results are introduced, and the truing performance is discussed. Research results show that the proposed new method is effective for truing metal bonded diamond grinding wheels.