Advances in Abrasive Technology XII

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Authors: Thai Nguyen, Liang Chi Zhang
Abstract: This paper presents a temperature-dependent finite element heat transfer model, incorporating a triangular moving heat source and various cooling conditions, to predict the three-dimensional temperature field in plunge surface grinding. The model was applied to analyse the grinding-hardening of quenchable steel 1045 using dry air and liquid nitrogen as the cooling media. The temperature field variation under such grinding conditions was also measured experimentally. It was found that the temperature history predicted by the model agrees well with the measured results. The model provides a fundamental study as a first step in optimisation and control of the hardened layer thickness and its compositions in grinding-hardening technology.
Authors: Xue Kun Li, Lan Yan, Waleed Bin Rashid, Yi Ming Rong
Abstract: Grinding is regarded as a special multiple edge cutting process, which can be decomposed into grain-workpiece interface, chip-workpiece/bond interface, and bond-workpiece interface at microscopic level. The grain-workpiece interface, which resembles a micro-cutting process, directly modifies the workpiece surface and dominates all the output measures of a grinding process. Therefore, the study of the grain-workpiece interaction through micro-cutting analysis becomes necessary. As the emergence of the packaged FEM software for micro-cutting simulation, apart from single grit cutting test, it enables another qualitative and quantitative investigation method on grain-workpiece interface mechanism in an efficiency and effective manner. In this paper, the efficacy of the commercialized cutting simulation software Third Wave AdvantEdgeTM is evaluated, and the possibility of using AdvantEdgeTM for in-depth understanding of grain-workpiece interface as well as grinding process modeling is studied, too.
Authors: Lan Yan, Xue Kun Li, Feng Jiang, Zhi Xiong Zhou, Yi Ming Rong
Abstract: The grinding process can be considered as micro-cutting processes with irregular abrasive grains on the surface of grinding wheel. Single grain cutting simulation of AISI D2 steel with a wide range of cutting parameters is carried out with AdvantEdgeTM. The effect of cutting parameters on cutting force, chip formation, material removal rate, and derived parameters such as the specific cutting force, critical depth of cut and shear angle is analyzed. The formation of chip, side burr and side flow is observed in the cutting zone. Material removal rate increases with the increase of depth of cut and cutting speed. Specific cutting force decreases with the increase of depth of cut resulting in size effect. The shear angle increases as the depth of cut and cutting speed increase. This factorial analysis of single grain cutting is adopted to facilitate the calculation of force consumption for each single abrasive grain in the grinding zone.
Authors: Taghi Tawakoli, Engelbert Westkämper, Bahman Azarhoushang
Abstract: The total removal of grinding wheel material includes two main parts. The larger of the two is the result of dressing and truing operation and the other relatively small part is due to the wheel wear which takes place during the actual grinding process. The frequency of dressing and truing operations depends on the cutting conditions, wheel characteristic, etc. However in dry grinding as there is no cutting fluid to transfer the heat from the contact zone, the wheel wear during grinding and the frequency of dressing is much higher due to the higher grinding forces and temperatures. Vibration grinding reduces wear of the grinding wheel during the process considerably and decreases the frequency of dressing operation significantly. Hence it increases the efficiency of the process and reduces the cost. The investigation carried out in the KSF institute shows the improvement on the surface roughness, reduction of the grinding forces, thermal damage of the ground surface and radial wear of the grinding wheel in case of using vibration grinding comparing to conventional grinding. The designed and developed ultrasonically vibrated workpiece holder and the experimental investigation show a decrease of up to 80% of radial wear of the grinding wheel.
Authors: C.S. Leo, T.L. Blackburn, David Lee Butler, Sum Huan Ng, C. Yang, Steven Danyluk
Abstract: With the demand for precise nanometric material removal with minimal defects, several non-contact ultraprecision machining techniques were developed over recent decades. The electrokinetic material removal technique [1] is one such method that allows material to be removed without any physical contact between the tool and the workpiece. In this work, the influence of the slurry mixture on the material removal rate for the electrokinetic material removal process is studied. During the process, it was observed experimentally that the mixture of the slurry affected the material removal rate. The parameters varied in the slurry mixture experiments were the size and concentration of the particles. Explanations for the behaviour of the material removal rate were also suggested during the study to further understand the electrokinetic material removal technique.
Authors: Berend Denkena, Marijke van der Meer
Abstract: Until now, the complex kinematics and geometries as well as high quality requirements have prevented the use of all-ceramic prostheses for the medical treatment of knee joints. High-precision grinding and polishing processes for free-formed ceramic surfaces are essential for this purpose. Constantly changing contact conditions have to be considered to ensure a constant material removal. Within this work, appropriate tools are introduced which are able to adjust to the form variation of the component contour.
Authors: Xavier Kennedy, S. Gowri
Abstract: Advanced structural ceramics have been increasingly used in automotive, aerospace, military, medical and other applications due to their high temperature strength, low density, thermal and chemical stability. However, the Grinding of advanced ceramics such as alumina is difficult due to its low fracture toughness and sensitivity to cracking, high hardness and brittleness. In this paper, surface integrity and material removal mechanisms of Alumina ceramics ground with SiC abrasive belts, have been investigated. The surface damage have been studied with scanning electron microscope (SEM). The significance of grinding parameters on the responses was evaluated using Signal to Noise ratios.This research links the surface roughness and surface damages to grinding parameters. The optimum levels for maximum material removal and surface roughness been discussed.
Authors: Y.G. Zheng, W.G. Liu, Bin Jiang, Hang Gao, S.G. Zheng
Abstract: According to the demand for internal grinding machine in precise machining of air-conditioner compressor piston hole, a kind of high precise CNC internal grinding machine with CBN wheel is developed by adopting self-adaptive control for grinding process. Meanwhile, grinding precision and stability are achieved by overcoming many problems emerging from high-speed grinding process with CBN wheel. More than 100000 times’ grinding experimental results show that the whole performance of grinding machine developed is the same as that of the same kind of international machine. In order to study grinding mechanism with CBN wheels and then improve machine’s capability, grinding data in several machining cycles is analyzed.

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