Papers by Keyword: Grinding Process

Abstract: For optimization and control of the grinding process, it is necessary to monitor the process state. Fluid selection for grinding process is also considered as key factor for surface quality. This study focuses on the effects of different fluids in grinding process using Acoustic Emission technology. The analysis is carried out grouping the tests according to the main measured: Acoustic Emission (AE) signals, Normal and Tangential Forces on the workpiece surface, Grinding Temperature and Surface Roughness. The potential of real-time monitoring grinding process using Acoustic Emission technology is also tested. The results of this research show that selections of grinding fluids do have a significant influence on response factors such as surface roughness and AE signals. Further, prediction of surface roughness during the grinding process using AE signal monitoring is demonstrated in this work.

Abstract: This paper indicates the occurrence of high thermal energy in the surface layer of workpiece material during the process of grinding. To help identify the share of heat which affects the workpiece, firstly the analysis of past research in the field of heat transfer during grinding was conducted. Further there is a proposition of analytical expression for heat distribution factor to the workpiece in the grinding process. Goal of this analytical dependence is to achieve more efficient production of mechanical parts without thermal defects in the surface layer of the part. Presented equation for energy partition has a characteristic of widespread practical use.

Abstract: In recent development of dental restoration, zirconia has been used as a prosthetic material due to their enhanced properties of fracture strength and toughness compared to other ceramic materials. Zirconia based ceramic materials are used in structural application in engineering, such as in the manufacture of cutting tools, gas sensors, refractories. Grinding was used as the efficient technique to finish ceramic materials. Due to the hard and brittle nature of a ceramic material, the grounded components were left with surface and subsurface damages. In this paper, the influence of the grinding parameters on the grindability of yttrium partially stabilized zirconia was carried out using a diamond grinding wheel. The resin bonded grinding wheel was used to analyze the grinding behavior of the material. The grinding force and surface roughness were measured during the grinding process and the experiments were conducted under conventional flooded conditions. The relationship between the surface finish and grinding parameters such as depth of cut, wheel speed were analyzed.

Abstract: In grinding process, the grinding wheel profiles are copied to workpiece surface. Therefore, the finished workpiece surface can be estimated by the grinding wheel surfaces. In this paper, new measuring method of the distribution of cutting edge in grinding wheel surface by two AE sensors is proposed. From experimental results, it is confirmed that the distribution of cutting edges in wheel surface can be measured easily by the proposed method compared to another measuring method.

Abstract: In a series of processes which occur in various processing industries, it is necessary that the raw materials, finished products or intermediate products to be grind to accelerate the technological phase, to obtain a product from raw materials or even only for commercialization the products [1]. Modeling program can be used to study and understand the behavior of an individual grain under compression stress. The results from previous studies have shown that the modeling program can be used [2] for predicting the grain deformation, the compression stress and the energy consumption obtained as a consequence of the grain compression process. This paper presents a comparison of a modeling and experimental study on the influence of the physical properties of a single corn seed on compression grinding process. The mathematical model by finite element method for the corn compression process is made in order to establish the forces that appear to the first cracks of the grain, to determine the maximum force of the corn compression, the deformations of the grain resulted after the compression and the energy consumption during the compression process. For this simulation it was used the mechanical structural module in 3D space of the COMSOL Multiphysics software. The experimental researches were carried out on an individual corn seed, using the materials testing machine Zwick / Roell 5 kN, to which was adapted the compression device [3]. In the experimental researches have been followed the same properties as at the mathematical modeling.

Abstract: This paper deals with an intelligent multi-sensor monitoring system, which focus on the characteristic of transient occurrence in high speed grinding and its application to the machining of brittle and hard materials. Different sensors are used to collect workpiece vibration, acoustic emission, force and displacement signals, which are used to define the stability of grinding process and monitoring the fault in high speed machining. Although there is a lot of methods have been reported in recent literature for monitoring grinding process, they have not a systematic method which can totally reflect the characteristic of high speed grinding. On the other hand，no single sensor or feature has been shown to be successfully and precisely all grinding faults. This paper combined different feature selection including time-frequency domain or wavelet methods and sensor fusion based on clustering method to deal with the stability condition test in high-speed grinding. The validity of the proposed method and the excellent detection accuracy is demonstrated through tests with SiC machining in high-speed grinding.

Abstract: The change of the specific surface area, particle size and activity index of ground granulated blast furnace slag under different grinding conditions is researched based on closed-circuit mill in the paper. The research shows that the grinding effect is greatly different with the different grinding body, and proper pre-grinding time can help to improve the grinding effect. The optimum plan in this paper is as follow: pre-grinding 15 min at steel bar then grinding 30 min at ball grinding, and it will getting the maximum specific surface area, the smallest powder particle size and the the maximum activity index.

Abstract: In order to improve the efficiency and reduce the cost of sapphire crystal machined by loose abrasive lapping, the fixed-abrasive diamond grinding tools for sapphire grinding were investigated in this paper. Four vitrified-resin composite bond diamond grinding tools with different grain sizes (40μm, 20μm, 7μm, 2.5μm) were developed. The grinding experiments were performed with the developed diamond grinding tools and the grinding performance of four grinding tools were evaluated by comparing the surface roughness and the material removal rate (MRR) of sapphire. The experiment results show that with the increase in grain size, both the MRR and the surface roughness increase. A high-efficiency and high-quality ultra-precision grinding process using diamond grinding tools with different grain sizes was proposed.

Abstract: In non-circular contour grinding process, a theoretical model of constant linear velocity grinding has been established based on the X-C Axis linkage motion principle of grinding machine. Based on this theoretical model, a numerical calculation model, which can be used for practical grinding process and can optimize and regulate the grinding speed, has be built by way of cubic spline fitting interpolation method. The calculated numerical result of this model can switch into NC code of some NC system. According to the motion principle of grinding machine, the geometry information of specific non-circle contour part and the real parameter of the grinding processing plan, the corresponding NC Programming function also has been modularized. An experiment has been done on the NC high speed camshaft grinding machine type of CNC8312A, and obtained the ideal processing effect.At the same time ,it also shows that the proposed method has strong practical feasibility and great practical value.

Abstract: Grinding process is a critical procedure of mineral process, and its running character is extremely important for the productivity and quality improvement. It is of comprehensive and complicated characteristics of nonlinearity, large time-delay, slow time-varying and so many key engineering parameters which can not be detected online. It is dramatically significant and difficult to study the control algorithms, the optimization algorithms and the soft censor techniques for grinding process. In order to decrease the cost and risk of practical debugging, how to establish a control simulation system of grinding process for engineering is an issue which has greatly practical value. The simulation experiment platform for grinding process control is designed and developed. The general structure of the platform including real control system and virtual production plant is proposed. Thus, a kind of engineering experiment environment is provided for control and optimization algorithms.