Applied Mechanics and Materials Vols. 633-634

Abstract: Keeping the water-repellent stability of superhydrophobic surface is necessary in application. Based on the total reflection of Cassie interface and vacuum technique, the superhydrophobic stability of the lotus leaf and an artificial material was investigated. The results show that during the Cassie-Wenzel transition, primary wetting transition occurs at a certain pressure that in accordance with theoretical prediction. However, when the air film is entrapped between microstructures, stability of water-repellency was greatly enhanced, and part of the wetting transition can be recovered when the pressure was released. Due to the micro-and nanoscale hierarchical structures, the lotus leaf shows better water-repellent stability and dewetting property than the artificial superhydrophobic surface when the hydrostatic pressure was applied and released.

Abstract: Graphite chip formation is important for the understanding of high speed milling of brittle graphite. This paper is aimed to reveal the influence of cutting conditions on the graphite chip formation in high speed milling. The relationship between the maximum undeformed chip thickness and cutting parameters was analyzed, and the influence of cutting parameters, tool geometry and milling patterns on the chip formation of brittle graphite was studied. It is concluded that the transitions of graphite chip formations were highly dependent on the undeformed chip thickness which is decided by the combination setting of feed per tooth and radial depth of cut. Big fractured block chip occurs more easily in up milling than down milling. Tool rake angle influences the chip formation according to the maximum undeformed chip thickness.

Abstract: The new method of laser prestressed bending of Titanium alloy sheet is put forward in this paper. Titanium alloy sheet is produced pre-deformation by a clamp, the laser beam with some certain intensity scans its surface along the given path, and it is formed due to the thermal effect of the laser to reduce the yield strength of the scanning area and enhance its plastic deformation ability. A feasibility experiment for Ti-6Al-4V sheet is done and the bending effect is remarkable. Laser prestressed bending mechanism is described and the main influence factors are analyzed.

Abstract: In order to enhance efficiency of laser engraving technology in fabric manufacture, a laser engraving experiment was conducted on 30 kinds of jeans with CO₂ laser engraving machine, and meanwhile the performance parameters of fabric was tested. Then five performance parameters of fabric were chosen through correlation analysis, with each showing a significant correlation with carving levels; a prediction model of carving level was constructed based on GRNN, with a prediction error of less than 3%.The study improves the efficiency of laser engraving and lays foundation for bridging the performance parameters of fabric and sculpture levels .

Abstract: Laser cladding on K418 substrate using NiCrWMo powder by Nb:YAG laser was carried out for the repair of aero blades. The microstructure and microhardness of cladding layers were investigated. The result showed that using the correct nickel based alloy powder, at the craft parameter of electric current 160 A, pulse width 8mses, the frequency 4 Hz, the surface is balanced and continuous; the microstructure is close and uniformity; the cladding is well combined with the substrate without flaw; the rigidity of the cladding is higher than the substrate .

Abstract: In order to improve the corrosion resistance of Ni-nanoZrO₂ composite coatings. By orthogonal test method,the process for composite electroplating of Ni-ZrO₂ was optimized involved current density、bath temperature、the ZrO₂ particle concentration. Corrosion resistance and the hardness were tested, microstructure was observed with a scanning electron microscope. The optimized technological conditions are:current density i4A/dm²,bath temperature 45°C, nanoZrO₂ addition 7g/L. In this optimum process condition, corrosion current density is 6.186×10^-6 A/cm², corrosion resistance is good, and its hardness is much better than pure nickel plating, also a flat morphology and compact microstructure Ni-ZrO₂ nanocomposite coating is get.

Abstract: The rolling force calculation procedure of strip cold rolling is developed based on influence function method, with consideration of the couple of roll flattening model and rolling force model. With the procedure total rolling force and the distribution of rolling force per width of each pass for HC mill are calculated using sampling data obtained from actual strip rolling. Comparing the calculation results with actual measured value, it is shown that the calculated total rolling forces are similar to actual data, and the distribution of rolling force per width is consistent with the actual status. It proved that the calculation method introduced in this paper is an effective method to calculate rolling force, and it can be used in the process control of strip cold rolling mill.

Abstract: The purpose of this article is to select the most appropriate sensor for the crane structural health monitoring. We used three kinds of sensors to do an equal strength beam test: The original sensor R₂ and R₄ which have been calibrated, American MOI FBG sensor and wireless strain sensor. After derived the formula of maximum normal strain, we have done equal strength beam test for 3 times. Then calculated their average and contrasted their linearity to see the accuracy of MOI FBG os3110 and wireless sensor. Compared with the experimental value theoretical value, the wireless sensor has the highest accuracy, it is even more accuracy than the original sensor R₂ and R₄ which have been calibrated; Departure from linearity aspect, the wireless sensor, the original sensor R₂ and R₄,all of them have small relative error rate, it is less than 10%, but MOI FBG os3110 has very large relative error rate; In order to compare the overall performance of the sensor, we can also compare the sensors from the sensitivity aspect, zero drift, detection range, and so on.

Abstract: In this paper, for the original target flatness curves of flatness control system of a 1450 cold rolling mill can't satisfy the actual production, parameter setting method is adopted to the supplementary setting of target flatness curves. Based on the analysis of the several common forms of orthogonal polynomials, Legendre orthogonal polynomials are selected in supplementary setting according to the actual flatness. Considering temperature compensation, recoiling compensation, edge compensation, and comprehensive control of flatness and crown, 18 supplementary setting target flatness curves is determined aimed at typical product of the mill. Actual production shows that after the supplementary setting target flatness curves put into use, the flatness quality of the product has improved significantly.

Abstract: Experimental investigation of adsorbent was conducted about the anti-corrosion additives on the surface of simulating axletree, testified the existence of physical sorption on the axletree surface through the molar consistency changes of anti-corrosion additives in lubricating oil before and after adsorbent experiments which represented by ultraviolet absorbance. Did adsorbing experiments using the cosmoline dashed with different content of anti-wear additives, found that anti-wear additives could affect the adsorbability between the axletree and anti-corrosion additives through ultraviolet absorbance measurements, the results reflect that the interacting sorption between the two additives on surface of axletree.