Based on a modified form of Archard’s wear theory, significant data were obtained using the finite element analysis code DEFORM during the process of warm extrusion, including instantaneous interface temperature, sliding velocity, and interface pressure distribution of every node. From the acquired data, the wear of the punch, the temperature–wear coefficient curve, temperature–wear depth curve, and temperature–hardness curve were acquired. The results show that the maximum wear occurred in the front working tape of the punch. The results are in agreement with actual conditions, and therefore, lay a foundation for forecasting die life and optimizing die cavity profiles using this method.

In order to improve the stress corrosion resistance of 316 stainless steel, a new technology was proposed and studied. The 316 stainless steel sample was treated by laser shock processing (LSP). The residual stress and microstructures of 316 stainless steel with and without LSP were measured and compared by the methods of X-ray, transmission electron microscopy (TEM) and Electron Back-ScatteredDiffraction (EBSD), and the strengthening mechanism was discussed. It showed that the high residual compressive stress introduced by laser shock processing was about-112 MPa. The TEM and EBSD results showed that severe plastic deformation and nanocrystals layer were formed by LSP, and the orientation of the grains had evident rotation in the process of plastic deformation. These helped to enhance the stress corrosion resistance of 316 stainless steel.

The CuCl-catalyzed reaction of aryl boronic acid with carbon dioxide to form carboxylate ester after treatment with CH 3 I has been developed. The procedure featured mild conditions and good functional group tolerances. A diverse range of aryl boronic acids were effectively converted into carboxylate esters. Even those bearing sensitive groups such as carbonyl, ester, and amide could produce the desired products in good yields.

In this paper, the microstructure and hardness of Ti-5Al-2Sn-2Zr-4Mo-4Cr titanium alloy with and without laser shock peening (LSP) were examined and compared. The titanium alloy samples were laser shock peened with different layers at the same power density. The microscopic structure after LSP are tested and analyzed by SEM and TEM. The results indicated that LSP changed the microstructure evidently. After 3 layers laser shock peening, there are nanocrystallization in the LSP zone. The shock wave provided high strain rate deformation and generated high-density dislocations in the material. Multiple severe plastic deformation caused by 3 to 5 LSP layers helped to rearrange the resultant dislocation, to form dislocation networks, leading to the formation of nanocrystallites. On the other hand, the microhardness across the polished surfaces of the titanium materials with and without LSP was measured. It is obvious that the laser shock peening improved the microhardness of the Ti-5Al-2Sn-2Zr-4Mo-4Cr for about 16% at the surface, and the affected depth is about 300 microns from the surface.

The goal of this work was to determine effects of laser shock peening (LSP) on the fatigue life of the nickel-based superalloy, as well as the mechanism including the residual stress-depth profile (both depth of compression and magnitude) and the microstructure. The vibration fatigue performance of the standard test coupons made by Ni-based superalloy K417 with and without laser shock peening is researched. The residual stress distribution and microscopic structure after LSP are tested and analyzed by X-ray diffraction, SEM and TEM. The results indicated that the compress residual stress is up to 1.0mm in the test coupons after LSP, and the maximum residual compressive stress is about 660MPa under the surface. At the same time, the high pressure shock wave caused by laser propagate into the material which formed high density dislocation in the surface of the samples, and the γ' is divided leading to increase the sub-grain. Because of the deep residual compressive stress, high density dislocation and much more sub-grains, the vibration fatigue strength is improved about 180MPa by LSP. It is very instructive in the structure design and applying LSP to Ni-based superalloy.