Papers by Keyword: Grinding Burn

Abstract: This study was performed to develop a non-destructive inspection system to detect grinding burn, which is capable of quantitative 100% inspection inside a production line. An eddy current sensor, which has advantages of short inspection time and low cost, was used. It was shown that the grinding burn detection technique had been developed and is possible to detect grinding burn by using this technique, in the 1st report¹⁾ and the 2nd report²⁾. In this report, an experiment of in-process detection of grinding burn was conducted, by applying the grinding burn detection technique which we have developed. The eddy current sensor has been combined with an in-process gauge in order to keep the clearance between the sensor probe and the work piece constant. It was shown that grinding burn can be detected successfully during cylindrical machining.

Abstract: The relationship between heat treatment processes and grinding performance of cold die steel 9Mn2V had been built in this paper. Serious meshy segregation of carbide, excessive amounts of retained austenite, coarse and inhomogeneous distribution of material structure were significant causes of grinding burn and grinding crack. In order to improve the abrasion-resistance and mechanical properties of workpiece material, cryogenic and tempering treatment were added. Disappear of meshy segregation of carbide, network carbide was within second grade, retained austenite content was within 4%, martensite became much more fine and homogeneous, all of these advantages could be obtained by adopting cryogenic and tempering treatment in twice. The grinding experiment results indicated that workpiece material 9Mn2V which using this process could provide superior grinding performance.

Abstract: As inner cooling grinding can break the closure of grinding area and solve practical engineering problems resulting from too high grinding temperature, it can be used to realize the grinding of difficult-to-machine materials, such as Titanium alloy, in a general machine such as M7130. An inner cooling grinding wheel, a grinding carriage and cutting fluid system are the key parts of a inner cooling grinding system, and an inner cooling grinding wheel must be fixed on a plain grinder by a grinding carriage, so this paper mainly studies how to design and manufacture a tooling for an inner cooling grinding wheel, which has simple construction and reliable performance. Grinding experiment shows it can dramatically reduce cutting temperature and effectively avoid grinding burn, thus grinding quality is improved.

Abstract: This study was performed to develop a non-destructive inspection system to detect grinding burn, which is capable of quantitative 100% inspection inside a production line. An eddy current sensor, which has advantages of short inspection time and low cost, was used. It was shown that the grinding burn detection technique had been developed and is possible to detect grinding burn by using this technique, in the 1st report¹⁾ and the 2nd report²⁾. In this report, we have attempted to apply the grinding burn detection technique to evaluate the residual stress of work piece surface. Residual stress of work piece surface is affected by both thermal and mechanical effects. It is shown that the residual stress is possibly evaluated in the case of the thermal effect is dominant.

Abstract: Thermal influences, introduced intentionally or unintentionally do have significant effects on surfaces of steel components. Materials properties are reduced by annealing effects or even re-hardening zones can occur. Grinding, one of the most important technological processes for preci-sion manufacturing of hardened steel components, is an important source of thermal influences to steel surfaces. In pronounced cases, these influences are referred to as grinding burn. They are known as possible reasons for gray stains as well as development of cracks and pittings on heavy-duty gears and on roller bearings. The basic effect of thermal influences on the material is a change of the macro- and micro-residual stress states. Therefore, the knowledge of these residual stress states is of fundamental importance. The paper treats the mechanisms of grinding which can lead to thermal influences. Some characteristic appearances of grinding burn are shown and characterized by X-ray macro- and micro residual stress determinations. It is shown that defined laser treatments can be used to create reproducible thermal influences similar to grinding burn. Their effects are also characterized by X-ray residual stress measurements. The sensitivities of X-ray and metallographical investigations are compared. Defined laser traces are proposed as calibration samples for magnetic and eddy current measurements which allow to determine threshold values for the actual apparatus and measuring problem.

Abstract: The high efficiency deep grinding is widely used in manufacturing. The experiments were carried out to study on the high speed deep grinding force and grinding burn and cracks in grinding 40Cr steel specimen with Al₂O₃ wheel. The experimental studies demonstrate that the grinding force increases with the grinding layer depth. The trail of grinding on space surface is blurred progressively, the surface topography deteriorates gradually. When the depth of grinding increases to the certain value, grinding burn appears, and micro-cracks emerge. Selecting the optimization parameter in high speed deep grinding can avoid the grinding burn and grinding cracks.

Abstract: In the grinding of high speed steel, the high temperature grinding zone often leads to poor surface quality such as grinding burn, micro-cracks and tensile residual stresses. In the paper, the cooling-air technology was adopted to study the grinding of high speed steel. The experimental results show that cooling-air grinding can effectively restrain the grinding burns, reduce the surface roughness value and improve the surface quality in comparison with dry grinding.

Abstract: Grinding is often used as the final manufacturing method which is an important processing method. Its’ quality of parts surface will directly affect the life and strength of mechanical parts. Therefore, the quality of parts surface in grinding is particularly important to mechanical parts. In this paper, after the simplification of theoretical model of the parts, we can use software such as WORKBENCH and MATLAB to obtain the temperature field of grinding and numerical simulation in case of 45# steel. Subsequently, it also makes use of LS-DYNA to carry out micro-morphology’s simulation in the process of grinding. Then it can significantly verify the previous simulation’s results. We preliminarily obtain the mechanism of the grinding burn on parts surface. It also shows the concrete impact on temperature field with the changing of grinding parameters. Finally we can receive the method to minimize the grinding burn.

Abstract: The chip removal process in grinding is characterized by intensive friction and plastic deformation leading to the risk of thermal damage of the surface-layer of the machined part. Thus productive and reliable grinding processes need effective monitoring. The difficult to access contact zone between the grinding wheel and the workpiece led to extensive research work on the temperature measurement in the grinding arc. In order to develop a tool integrated temperature monitoring system a new approach was undertaken which makes use of the measurement of infrared-radiation to monitor the temperatures in the grinding arc. The presented research work shows promising results suitable for an industrial applicable system for temperature measurement in grinding. The optical transmission of the infrared temperature information in combination with a fast detecting infrared sensor bares the potential to establish a highly miniaturized measuring system which is easy to integrate in any grinding wheel at comparably low production costs.

Abstract: This paper looks at the multiple characteristics and investigations of two grinding anomalies: grinding burn and grinding chatter. A genetic programming (GP) of multiple classifications was investigated for different machining strategies and associated anomaly phenomena. Such a GP paradigm could evolve rules to provide the correlation between monitored signals and grinding phenomena. The investigation also looks at both Short-Time Fourier Transforms (STFT) and Wavelet Packet Transforms (WPT) to convert the raw acoustic emission (AE) signal into a time based frequency signal, segmented into different frequency bands. A set of encouraging results is presented.