Abstract: Be and HR-I stainless steel with AgCu28 as an interlayer was diffusion bonded by hot pressing，The microstructure，distribution of composition and phase，mechanical properties of the joints were analyzed using scanning electron microscopy(SEM)，scanning auger microspectroy(SAM)，x-ray diffraction(XRD) and material testing machine，and the relationship between composition and structure and properties，and the effect of interlayer materials AgCu28 alloy were also discussed．The results show that good joint can be obtained using AgCu28 alloy as an interlayer material，because it can reduce the mutual diffusion between beryllium and stainless steel elements，the formation of brittle intermetallic compounds between beryllium and stainless steel elements are avoided effectively to improve the diffusion bonding strength and properties．
Abstract: This paper reports on experimental test and numerical simulation methods that investigate the stress concentration factor and node deformation performance parameters for tubular KK-joints. The numerical analysis can give reference for design schemes of model test, and the bearing characteristics are studied by the model test. Moreover, by comparing the experimental analysis and the finite element simulation results, we discuss the accuracy of numerical analysis method in analyzing the tubular joints stress concentration factor. These can provide a useful reference for the engineering design.
Abstract: The orthogonal experimental design was conducted for linear friction welding of Ti-6Al-4V titanium alloy (TC4). The friction power and joint temperature were collected during the welding process. The influence of process parameters on the axial shortening was analyzed. The suitable process parameters were determined by investigating the joint appearance, the requirement of axial shortening and welding variables during welding. The results provide important reference for establishing process parameters of linear friction welding in practice.
Abstract: The swelling effect is an important factor to affect surface generation in SPDT. Face cutting experiments are conducted for copper, aluminum alloy and electroless nickel phosphorus to analyze the swelling effect including the relationship between it and cutting parameters as well as effect of material property. How the material swelling affects surface roughness is also studied in this paper. The results indicate that the swelling effect is influenced by spindle speed and material property more remarkably when compared to feed rate and depth of cut. In addition, a softer and more ductile material will lead to a stronger material recovery, a lower swelling proportion, a lower tool mark height and a smoother machined surface. The result reveals that the swelling effect must be considered when predicting surface roughness in SPDT
Abstract: Preloading the high strength bolt using hydraulic extension method is a fast and efficient method for bolt installation. Hydraulic bolt tension device can guarantee the initial tension of bolt well. However, if the relation of initial tension and the final remaining preload of bolt cannot be determined, the preload on the bolts still cannot be guaranteed. This paper uses theoretical analysis method to research the relation between the eventual preload and the initial tension of high strength bolts on Heavy-duty Gantry beams. Then we proposes a set of calculation method of bolt installation preload and the initial tension and provides theoretical basis for the installation of heavy-duty segmented beam.
Abstract: The basic hypothesis of this article focuses on the study of cutting tool wear with regard to the elimination of occurrence of poor-quality holes when drilling into new austenitic stainless steel. The problem of drilling holes with diameter D=3 to 10 mm resides in the fact that 20 to 30% of these holes do not comply with prescribed requested requirements. This article presents the results of experiments focusing on the study of the damage process in screw drills with diameter d=6.0 mm when drilling into new austenitic stainless steel X02Cr18Ni10MoTiN. This study also includes an analysis of accompanying phenomena in the cutting zone by measuring some selected parameters. The results of the experiments were compared with Cr18Ni8 steel and then verified when drilling holes into specific products.
Abstract: Maximum thickness reduction ratio is used to predict sheet metal forming limit in the numerical simulation of forming process. The maximum thickness reduction ratio under different stain path is not a constant for the same material. The effect of strain path and strain hardening exponent on forming limit is considered. The relationship between the maximum thickness reduction ratio that the material can obtained and the strain path between tensile to equi-biaxial is established. The parameter in the criterion can be determined by tensile experiment combined with numerical simulation of the same forming process. Then the limit strains under other linear strain paths between tensile to equi-biaxial can be determined by the criterion combined with numerical simulation of corresponding forming process. Forming limits of three kinds of sheet metals are predicted with the modified maximum thickness reduction ratio criterion. Good agreement is achieved between the predicted data and the experimental data.
Abstract: Welding seam tracking precision is a key factor influencing welding quality for master-slave robot remote welding system. However, it does not satisfy the welding requirement due to significant noises. To eliminate the influence of noises upon the seam tracking precision and improve the seam tracking precision, a master-slave robot remote welding system was built and Kalman filtering (KF) was applied to the seam tracking process. The experimental results show that the KF eliminated the influence of noises upon the seam tracking precision and improved the seam tracking precision.
Abstract: Abstract. In order to study the plastic flow during linear friction welding (LFW), copper particles were added as tracers on the surface of lead block. The flowing state of interior metal in LFW was simulated by the home-made simulator. Results show that the upset speed promotes the plastic flow of metal and the oscillation frequency restrains it. The upset speed influences the plastic flow of metal more significantly than the oscillation frequency. Only when the pressure reaches 800N and the increasing rate reaches 100N/s, can obvious plastic flow of lead happen in the direction perpendicular to the compression. But the plastic flow of lead in the compression direction is visible even if the pressure and its increasing rate are small.
Abstract: In view of major problems for the current metal cutting technology, a combined sand coated wire electrochemical machining technology is introduced. This method uses porous silicon carbide coated in metal wire electrode for grinding and electrolytic machining, which has both wire electrolytic and sand wire grinding characteristics, and greatly improves the cutting efficiency. The composite wire electrochemical cutting technology principle is analyzed. The method for determining the main process parameters is presented, and the effectiveness of its application in thin-walled metal pipe cutting is validated.