Applied Mechanics and Materials Vols. 556-562

Abstract: Successful synthesis of room-temperature ferromagnetic semiconductors, (Cu, Co) co-doped ZnO film is obtained by sol-gel method. It is found that the essential ingredient in achieving room-temperature ferromagnetism is Cu co-doping. By Hall-effect measurement a p-type conductivity was observed for the Cu co-doped films, which induced the room-temperature ferromagnetism.

Abstract: Abandoned cellulose was treated with acid to prepare Micro-Crystalline Cellulose (MCC) holding affirmative polymerization, which was then treated with 1,4–butanesultone (BS) to synthesize water-soluble Sulfo-Butylated Cellulose ether (SBC). The structure of the SBC was characterized by means of FT-IR, ¹H NMR, SEM, and XRD, and its relationship to function was investigated based on the polymerization of MCC and Degree of Substitution (DS). SEM images of hardened cement were also studied. The results indicated that when the polymerization of the MCC was smaller than 96 and the DS greater than 0.375, SBC exhibited water-reduction. When sulfonated cellulose was mixed into the cement paste, its retarding effect slowed hydration early in the aging process, so that later the structure of hardened cement paste became more uniform and compact than that of control.

Abstract: The influence of molecular structure of polycarbonate on performance was systematically investigated by both experiment and molecular simulation. Different types of polycarbonate molecular chain models were built and analyzed by molecular simulation method. By combining experimental and simulation results, it is concluded that the polycarbonate-OQ2720 has better thermal stability, mechanical properties and optical performance, which is a better choice for aviation materials and manufacturing process.

Abstract: The cause of welding cracks in thermal sprayed water wall tubes was analyzed, the choice of nondestructive testing method was discussed, and a welding procedure for the water wall tube with thermal sprayed coatings was established successfully.

Abstract: This document explains and demonstrates how to prepare your camera-ready manuscript for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. The text area for your manuscript must be 17 cm wide and 25 cm high (6.7 and 9.8 inches, resp.). Do not place any text outside this area. Use good quality, white paper of approximately 21 x 29 cm or 8 x 11 inches (please do not change the document setting from A4 to letter). Your manuscript will be reduced by approximately 20% by the publisher. Please keep this in mind when designing your figures and tables etc.

Abstract: Through the composite electrodeposition process of preparation of Ni - TiN nanocomposite plating, laser processing on its surface strengthening processing, using SEM, XRD, scratches on the surface morphology and composition were analyzed. Amount of nanoparticles suspension in plating solution is studied for nanocomposite coating under dry friction condition wear resistance; After laser hardening on the surface of a coating the hardness, wear resistance test, and optimize the electrical parameters. Ultrasonic electric sediments compared with ordinary mechanical stirring electric sediments, the surface is more meticulous, uniform, less pinhole; Laser assisted processing, makes up the defect of the general nickel plating adhesion strength is poorer, to some extent, to expand the application range of nickel plating.

Abstract: In many industries, such as chemical industry, food industry and cement industry, rolling drum are widely used for the mixing of solids which in many cases is the mixture of particles of different sizes. The quality of product is directly determined by the mixing uniformity, thus it is desired to guarantee the stability of mixing extent of rolling drum. This paper describes a new structure design for the mixture of different sizes of particles, and an image-analysis-based experimental method to verify the effectiveness of this new structure. Results of the experiment showed that using the new structure would enable a faster mixing rate, and obtaia higher mixing extent relative to the traditional structure.

Abstract: To solve the problem of low material utilization in traditional stretch forming process, a flexible stretch forming method was proposed, which can be realized by interaction of the multi-point stretch forming die with discrete-gripper stretch forming machine. The principle and characteristics of sheet metal flexible stretch forming technology was introduced, structural composition and working principle of the multi-point stretch forming die and discrete-gripper stretch forming machine were expounded, and the technology experiments was carried out with a self-designed flexible stretch forming technology equipment for sheet metal. The experimental results indicate that structure of multi-point stretch forming die and discrete-gripper stretch forming machine are reasonable, and flexible stretch forming technology can be realized by above-mentioned die and machine, stretch forming parts has a good quality and its shape error can satisfy requirements of production.

Abstract: Based on the SSRT, by simulating different forms of applied loads, the paper conducts the research on the influence and mechanism of action from different waveforms upon the stress corrosion of pipeline steel. Results show that under the given F - SSRT testing condition, and when the fluctuation frequency and fluctuation amplitude are same, the sensitivity of the stress corrosion produced upon X70 pipeline steel is the weakest under the F-SSRT testing condition of superimposed square wave, and is the strongest under the F-SSRT testing condition of superimposed sine wave, which shows that the sensitivity degree of stress corrosion of materials under the F-SSRT with different load waveforms is obviously different.

Abstract: The continuous cooling transformation (CCT) curve of 12Cr2Mo1R pressure vessel steel was measured on Gleeble-1500 hot simulator. The transformation and structures were observed and analyzed. Test results show that with the addition of Cr and Mo, ferrite and perlite transformation temperature increases while bainite transformation temperature decreases, resulting in bainite zone separating from ferrite and pearlite zone. The critical cooling rate for martensite is 30 °C/s.