Advanced Materials Research Vols. 602-604

Abstract: The hot deformation behavior of CL60 rail wheel steel has been studied by employing both processing maps and microstructural observations. Tests are performed at temperatures of 800—1100°C and strain rates of 0.1s-1—5s-1 and the flow stress data obtained from the tests are used to develop processing maps. The microstructural evolution of deformed samples is also examined on the basis of optical microscopic observations. The result indicates that under experimental conditions this alloy shows dynamic recrystallization(RDX) characteristics during hot compression deformation. Both deformation temperatures and strain rates have obvious influence on flow stress and its corresponding peak strain, which increase gradually with decreasing temperature and increasing strain rate. RDX occurred at higher temperature and lower strain rate.

Abstract: In the finishing machining, processing parameters directly affects the quality of machined surface. While the micro topography of the surface maps with the fractal dimensions. The paper researched the relation between processing parameters and fractal dimensions through the experiments in order to obtain the relationship. Through the design of orthogonal rotation experiment, determine the experimental parameters. Then measure the experimental sample for the surface and calculate the fractal dimensions using the box counting method. In the end, obtain the functional relation of processing parameters and fractal dimensions by regression method. The results show that the specific processing parameters of the surface can predict the fractal dimension by this formula. And this provides reference for selection of processing parameters.

Abstract: This paper includes the result about the traditional preparation process on the basis of improved powder metallurgy method by using the hot press molding process. The aim of the process is to enhance the preparation of 5,7,10 body size of SiCp / Al functional graded composites. Moreover, the performance of impact toughness has been addressed and analyzed through solid study. The result can be concluded as following: The preparation via vacuum hot pressing process of SiCp / Al FGM has been performed good enough to reduce the cost of secondary processing; 5 SiCp/Al FGM shows better impact toughness properties in the test.

Abstract: Size effect is a critical factor that needs to be considered when conducting micro mechanical machining processes. In this paper, a cutting process simulation technology is used to simulate a single tooth’s engagement with workpiece from the entry point to the exit point in a slot milling operation. The obtained specific cutting forces from simulation are employed to analyze the size effect and the minimum chip thickness with variable radii of tool edges. Micro machining experiments with different machining conditions are implemented by use of a high speed and high precision machining spindle to investigate the size effect on machined surface integrity and burr width. The optimal cutting parameters have been analyzed based on the simulation and cutting test results.

Abstract: In this paper, the factors affecting the surface roughness by flank milling are selected, and the blade machining experiments are implemented according to the orthogonal table designed, Then, the blade surface roughness are measured using TR200 instrument, and the surface roughness of the blade results are analyzed using visual analysis method and variance analysis method. Finally, the impact of various factors on the blade roughness is obtained, and the optimal process parameters of flank milling aluminum alloy blade are given.

Abstract: Enamel jewelry is carefully manufactured using glaze and gold, silver, copper and other precious metals. The processing technologies refer to multidisciplinary knowledge, such as painting, engraving, padding, inlaying, metallurgy and glass melting. The history of enamel was reviewed and the current challenges of enamel jewelry industry were investigated. The key challenges of the enamel jewelry industry are listed as follows: the counterfeit products dominate the enamel market, high performance enamel glaze is currently unviable, the industry standards have not been proposed, and the manufacturing technique is too complicated to be implemented by machine at this stage.

Abstract: Internal oxidation Cu-Al alloy sheet processing has been used to prepare dispersion-strengthened Al₂O₃/Cu composites. A new technique has been developed that successfully avoids mixed Cu-Al powder preparation, H₂-reduction, and sintering processes. The microstructure and phase were investigated by metallurgical microscope, SEM, and TEM. Holding-time, internal oxidation temperature and thickness of Cu-Al alloy sheet were the three key factors with regard to preparing Al₂O₃/Cu composites by internal oxidation in Cu-Al alloy sheet. The mechanical characteristics and electric properties of Al₂O₃/Cu composites sheet and hot-extruded rod were examined. The results show hot extrusion process enhances microhardness and ultimate tensile strength to a higher level with and exerts a little influence on high electrical conductivity.

Abstract: Red copper is difficult to process with laser for its high reflection rate and high density. On the contrary, with the development of Modern Laser Micro-Jet processing, the new Laser Micro-jet with 30μm and 130μm are utilized to process new area like red copper plate etc., new Laser Micro-jet with 30μm nozzle is redesigned as well as working experiment on red copper is carried out. Red copper is machining with the Laser Micro-Jet The experiment shows the methods can improve the red copper‘s machining quality, on the contrary, the result of experiment shows the new laser processing methods can machine red copper efficiently.

Abstract: On the foundation of taking equipment and production technology into consideration,we present a set of combined setting technology of the parameter of the strip suit to cold reduction mill of roll four and framework five。Then the parameter of the strip was controlled combined and coordinated of framework 1-5. On the one hand,it ensures the function of the force of the bending roll not cancel out mutually,and enhances the controlled effect of the force of the bending roll in the strip,on the other hand, there will not be new extra and partial shape wave under the complex effect of the force of the bending roll.Meanwhile there will not be the problem that the force of the bending roll in some parts get too high even overall loading while the other parts get get too low in the setting procedure.While improving the lifespan of the fluid cylinder, the adjusting rest of the force of the bending roll get increased. While the related technology has been adopted by field engineering, we have achieved excellent result, and there is the value for more expanding.

Abstract: According to the status of rolling middling stock without crown control on the single rough stand in semi-continuous hot strip rolling in domestic, the advantages and the working mode of middle plate rolling with proportional crown are introduced. Finally, the ways to improve the existing rough mill with CVC technology are discussed.