Advanced Materials Research Vols. 154-155

Abstract: With the development of photoelectron technology, optical glass and glass ceramic has been used in many different fields. The final machining of this kind of material has very important effect to its future application. In the present study, optical glass and glass ceramic is finished using laser polishing. Laser polishing could eliminate subsurface damage, smooth micro roughness. In certain cases a preheating system should be needed to increase optical glass’ surface integrity. The result shows that laser polishing of optical glass and glass ceramic has higher efficiency compared to conventional optical machining. The flexibility of laser polishing makes it ideal as an enabling technology for the final manufacturing of optical glass and glass ceramic.

Abstract: The researches of surface enhanced Raman scattering spectrum enhancement factor are based on low concentration of the solution, while the selection of solution concentration on the enhancement factor is ignored. In this paper, the substrate of nano-pillar forest structure whose density is controllable was fabricated. Using the high ability of enhancement, Raman scattering enhancement under different concentration (10g / L ~ 10-5 g / L) was tested and researched .The results indicate that the enhancement factor has close relationship with concentration, that is to say the enhancement factor will arise with the concentration decreasing. The main element, which affects the variation of the enhancement factor, is due to the change of efficiency polarization of CV molecule adsorbed on the Au nano- pillar.

Abstract: Metal transfer mode of the lime titania type structural steel covered electrode is a mixed one that coexists as the globular short-circuiting transfer, the flux-wall guided transfer, the explosive transfer and the spray transfer. Constitute of the metal transfer modes has a direct effect on usability of the covered electrode. Using the Analysator Hannover, the welding electric parameters are measured and analyzed. Four characteristic information values correlated with usability of the covered electrode are extracted, such as the sum of probability density of the short-circuiting voltage, variation coefficient of the arc voltage, the sum of probability density of the big short-circuiting current and the short-circuiting frequency, and then method of the principal component analysis is applied to determining evaluation index of usability of the covered electrode. Usability of the covered electrode is quantitatively evaluated. It offers a new method for scientifically evaluating usability of the lime titania type structural steel covered electrode.

Abstract: In sheet metal forming process, the input process parameters scatter and considerably result in unreliablity in practical production. Optimization for sheet metal forming process is often considered as a multi-objective problem. An optimizition strategy for high strength steel (HSS) sheet metal forming process was suggested based on response surface methodology (RSM). Latin Hypercube Sampling (LHS) method was introduced to design the rational experimental samples; the objective function was defined based on cracking factor wrinkle factor and severe thinning factor; the accurate response surface for sheet metal forming problem was built by Least Square Method; Multi-objective Genetic Algorithm(MOGA) was adoped in optimization and Pareto solution was selected. The strategy was applied to analyze a HSS auto-part, the result has proved this method suitable for optimization design of HSS sheet metal forming process.

Abstract: Based on the mechanism of vibrating stress relief and standard of JB/T5926-2005, vibrating stress relief method is used to eliminate residual stress of crane beam flange with butt weld. The welding residual stress of measured points is obtained by using blind-hole method. Experimental results show that the peak value of residual stress is reduced significantly, and the stress decline rate of residual stress is greater than the minimum requirement value of JB/T5926-2005. The effect of VSR method is remarkable.

Abstract: This paper discusses the artistic processing techniques of Chinese traditional architectural stone carving, and describes the classification of stones, procedures of processing technology, transformations of artistic style in the development of the society, as well as comparisons of the style of the architectural stone carving between central plains and Guangdong Chaozhou and Shantou areas, formations of local characteristics and evolutions of each historical period. This paper also probes into the artistic processing techniques and esthetics of Chinese architectural stone carving, and initiates people to have profound understanding to the artistic values of Chinese traditional architectural stone carving, in order to provide references in modernization strategy, and enable new development of artistic processing of modern architectural stone carving.

Abstract: In order to solve the problem of the alloy can not achieve the low surface roughness value in high-temperature, when it is grinded by abrasive disk, so that it can not meet the requirement of the craft. It uses abrasive belt grinding technology,adopts the method of fixed precise belt vibration grinding head on the CA6140 lathe and makes experiment of the impact on roughness of work piece surface from rotational speed of work piece , sand size of abrasive belt, horizontal amount of feed and process time. The result shows that the roughness value can achieve the requirement. It generalized the method of using abrasive belt grinding high- temperature alloy to make the roughness meet the requirement of craft, when guaranteed efficiency.

Abstract: In this paper, mechanical properties of unidirectional hot tensile tests of 3mm thick AZ31 magnesium alloy sheet metal are researched at elevated temperatures and under different tensile speeds. In this basis, thermal deep drawing of cylinders tests for 3mm thick AZ31 magnesium alloy sheet are investigated at elevated drawing temperatures, different drawing speeds and so on. Thermal deep drawing performance showed that set pieces better when elevated temperature and drawing speed range are appropriate to deep drawing.

Abstract: In this paper, a mathematical model of the process of bubble dissolution is built .In this model , the DeWitt constitutive equation reflect is used, it can reflect the performance of non-Newtonian fluid and calculation is relatively simple. The model was solved by finite difference method, and the results show that the initial bubble radius and the outside pressure is the main factor affecting the bubble dissolution.

Abstract: Based on “physical field coupling” finite element method, the generation of residual stress and interactive coupling effect were analyzed during the forming process of aluminum alloy thick-plate. Therefore, comprehensive residual stress generated from rolling, quenching and stretching was obtained. The finite element model was proved effective by comparing the results of simulation and experiment. Results show that percent reduction has significant influence to the distribution and magnitude of rolling stress; There is a coupling effect between rolling stress and quenching stress, which represents a basic state; Furthermore, after stretching the distribution of coupling stress remains, but the value reduces greatly; The residual stress has got the minimum, when stretching is near 3%.