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Spindle rotation error affects the machining accuracy of turning workpieces. Through analyses and studies of the spindle rotation error， a 2-D surface topography detection method was proposed for turning workpieces based on the rotation error， and the turning process model was established. The MATLAB simulation results showed that the spindle radial rotation error affects the turning radius and surface topography of the workpiece， resulting in the coaxiality error， roundness error and surface roughness. To verify the effectiveness of the proposed method， the 2-D surface topography detection platform for data collection was built， and the rotation error value of the spindle in the depth direction and average radius error of turning workpieces were obtained. The experimental results showed that the experiment and simulation results are consistent in characteristics， which verify the feasibility of the method and have reference value for the performance debugging of the machine tool and improving the processing quality of the workpieces. [ABSTRACT FROM AUTHOR]

In order to explore the evolution mechanism of surface corrosion of pre-stress grinding and the influence of grinding parameters on the corrosion resistance of stainless steel, 304 stainless steel was taken as the research object, a numerical model considering the influence of pre-stress grinding surface topography on the corrosion resistance of stainless steel was established. Firstly, the phase field equation for the corrosion field of rough surfaces was derived. Secondly, the surface topography model of the workpiece of pre-stress grinding was established. Finally, an auto-correlation wheel surface model with non-Gaussian distribution characteristics was built. With all the built models, the corrosion resistance of pre-stressed grinding surfaces was explored. Compared with the existing research results, the conclusions obtained conform to the general law, which verifies the rationality of the proposed method. The results showed that the pre-stress grinding surface has the "polishing effect" in the corrosive environment. As the corrosion time extends, the surface corrosion resistance is enhanced. In the condition of using coolant, appropriately increasing the pre-stress, wheel speed, and reducing feed speed can improve the corrosion resistance of the machined surface. When the pre-stress is a fixed value, the method of optimizing the linear speed and feed speed of the grinding wheel could also be used to further improve the corrosion resistance of the stainless steel workpiece. [ABSTRACT FROM AUTHOR]

Ｔｏ ｓｔｕｄｙ ｔｈｅ ｇｒｉｎｄｉｎｇ ｐｒｏｃｅｓｓ ｐｅｒｆｏｒｍａｎｃｅ ｏｆ ２.５Ｄ Ｃｆ / ＳｉＣ ｃｏｍｐｏｓｉｔｅｓꎬ ｓｉｎｇｌｅ ｆａｃｔｏｒ ｔｅｓｔｓ ｗｅｒｅ ｄｅｓｉｇｎｅｄ ａｎｄ ｅｘｅｃｕｔｅｄ. Ｔｈｅ ｒｅｓｕｌｔｓ ｓｈｏｗ ｔｈａｔ ｇｒｉｎｄｉｎｇ ｄｅｐｔｈꎬ ｗｈｅｅｌ ｓｐｅｅｄ ａｎｄ ｆｅｅｄ ｓｐｅｅｄ ｈａｖｅ ｐｒｏｍｉｎｅｎｔ ｉｎｆｌｕｅｎｃｅ ｏｎ ｔｈｅ ｐｒｏｃｅｓｓｉｎｇ ｐｅｒｆｏｒｍａｎｃｅ ｅｖａｌｕａｔｉｏｎ ｐａｒａｍｅｔｅｒｓꎬ ｉｎｃｌｕｄｉｎｇ ｓｕｒｆａｃｅ ｔｏｐｏｇｒａｐｈｙꎬ ｓｕｒｆａｃｅ ｒｏｕｇｈｎｅｓｓ ａｎｄ ｇｒｉｎｄｉｎｇ ｆｏｒｃｅ. Ｉｔ ａｌｓｏ ｉｍｐｌｉｅｓ ｔｈａｔ ｔｈｅ ｇｒｉｎｄｉｎｇ ｄｅｐｔｈ ｉｓ ｔｈｅ ｍａｘｉｍａｌ ｉｎｆｌｕｅｎｃｅ ｆａｃｔｏｒꎬ ｗｈｉｌｅ ｆｅｅｄ ｓｐｅｅｄ ｉｓ ｔｈｅ ｍｉｎｉｍａｌ ｏｎｅ. Ｄｕｅ ｔｏ ｄｉｆｆｅｒｅｎｃｅ ｏｆ ｓｕｐｐｏｒｔｉｎｇ ｅｆｆｅｃｔｓ ｏｆ ｔｈｅ ｗａｒｐ ｆｉｂｅｒ ａｎｄ ｗｅｆｔ ｆｉｂｅｒꎬ ｔｈｅ ｄｅｆｅｃｔ ｆｏｒｍｓ ｏｎ ｔｈｅ ｍａｃｈｉｎｅｄ ｓｕｒｆａｃｅ ａｒｅ ｄｉｆｆｅｒｅｎｔ. Ｔｈｅ ｍａｉｎｌｙ ｓｕｒｆａｃｅ ｄｅｆｅｃｔｓ ｏｆ ２.５Ｄ Ｃｆ / ＳｉＣ ｃｏｎｔａｉｎ ｉｎｔｅｒｆａｃｉａｌ ｄｅｂｏｎｄｉｎｇꎬ ｃｒａｃｋꎬ ｆｉｂｅｒ ｏｕｔｃｒｏｐ ａｎｄ ｐｕｌｌｏｕｔ. Ｉｎ ａｄｄｉｔｉｏｎꎬ ｄｉｆｆｅｒｅｎｔ ｇｒｉｎｄｉｎｇ ｃｈｉｐｓ ｗｏｕｌｄ ｂｅ ｐｒｏｄｕｃｅｄ ｗｉｔｈ ｄｉｆｆｅｒｅｎｔ ｇｒｉｎｄｉｎｇ ｐａｒａｍｅｔｅｒｓ ａｎｄ ｆｉｂｅｒ ｏｒｉｅｎｔａｔｉｏｎｓ. Ａｃｃｏｒｄｉｎｇ ｔｏ ｔｈｅ ｅｘｐｅｒｉｍｅｎｔａｌ ｒｅｓｕｌｔｓꎬ ｔｈｅ ｇｒｉｎｄｉｎｇ ｍｅｃｈａｎｉｓｍ ｏｆ ２.５Ｄ Ｃｆ / ＳｉＣ ｗａｓ ｒｅｓｅａｒｃｈｅｄ ｉｎ ｄｅｔａｉｌꎬ ｗｈｉｃｈ ｓｕｐｐｌｉｅｓ ｓｉｇｎｉｆｉｃａｎｔｌｙ ｔｅｃｈｎｉｃａｌ ｓｕｐｐｏｒｔ ｆｏｒ ｉｎｖｅｓｔｉｇａｔｉｏｎ ｏｎ ｔｈｅ ｇｒｉｎｄｉｎｇ ｔｈｅｏｒｙ ｏｆ ２.５Ｄ Ｃｆ / ＳｉＣ. [ABSTRACT FROM AUTHOR]

The specific rate of breakage(S○1)and primary breakage distribution(Bi,j)of untreated and microwave-treated vanadium titano-magnetite(VTM) with different particle size were investigated using grinding kinetics， and the variations of surface topography and phase composition of ground products were analyzed. The results show that the breakages of both untreated and microwave-treated VTM obey the first-order grinding kinetics. The S○1 of microwave-treated VTM is higher than that of untreated ore and the S1 increment increases with increasing particle size. The primary breakage distribution parameters(γ) are dependent upon the feed particle size. The γ value of Bi,j of microwave-treated VTM is less than that of untreated ore. The SEM analysis shows that the ground products have smaller particle size and rougher surface after microwave treatment. The XRD analysis shows that microwave-treated VTM has stronger diffraction peaks and larger amounts of gangue phases after ball mill， compared to those of untreated ore， which indicates that the degree of dissociation of ore is improved. [ABSTRACT FROM AUTHOR]

At present， most studies about the seal are based on the assumption that the seal surface topography and friction conditions are changeless. The influence of the seal surface topography on the leakage is mostly ignored as well as the effect of the microscopic perspective. Based on the fractal theory， the contact between surfaces of dynamic and static rings was simplified to the contact between rough surface and the ideal rigid plane， and a mechanical seal leakage model was established. The effects of fractal parameters， the surface unit load and material parameters on leakage rate were studied to obtain that the mechanical seal fractal dimension D and the end face specific load p○g were inversely proportional to the leakage amount Q. The characteristic length scale parameter G and the comprehensive elastic modulus E were proportional to its leakage amount Q. The calculated leakage rate and experimental data verify the accuracy of the model. [ABSTRACT FROM AUTHOR]

For the machinability difficulty of GH4169 Ni-based superalloy and 5A06 Al-Mg alloy as well as the high demands of machined surface quality and machining precision, the ultrasonic vibration assisted turning machining system was designed utilizing the method of ultrasonic vibration, which proceeded with cutting principle and machining technology. The contrast test was conducted to compare ultrasonic vibration assisted turning with conventional turning for these two alloy materials. The results indicate that the technological parameters have obvious effect on the surface roughness, surface topography and chip morphology of machined workpiece when ultrasonic vibration assisted turning of Ni-based superalloy and Al-Mg alloy is conducted. Choosing reasonable technological parameters can promote efficiently the processing quality, and enable the machining effects of ultrasonic vibration assisted turning to be superior to that of conventional turning. [ABSTRACT FROM AUTHOR]