The ancient Chinese casting techniques

In the course of Chinese civilization,which lasted more than 5,000 years,casting production has made a huge contribution.In this paper,some representative metal castings were presented.According to their forming techniques,they can be grouped into stone mould casting,clay mould casting,ablation casting,lost wax casting,stack casting,permanent mould casting,sand casting,etc.According to their materials,they can be categorized into tin bronze,bimetallic bronze,malleable cast iron,ductile cast iron,brass,cupronickel alloy (Packtong),etc.According to their surface decorative techniques they can be devided into gem inlay,gilding,gold and silver inlay,copper inlay,engraved decoration,surface tin-enrichment,mother-of-pearl inlay,burnished works with gold or silver inlay,surface coloring and cloisonné enamel,etc.

Influence of Casting Technique on the Mechanical Properties of Bimetal Composites

According to the characteristic of two liquid and bimetal composite interface,the influence of the casting techniques on the interface microstructure,wear and comprehensive properties were researched by using scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDAX).The results show that the casting technique has an effect on the surface quality and the stress state of the composites,but also has great effect on the interface microstructure,morphology and constitute phase.In this paper,a special casting technology was used to prepare the bimetal composites.No two-metal mixture layer was observed at the interface.On the contrary,a metallurgy interface was found,which provides high working security.A product rate of 95% was achieved by this special casting process.The service life is 50% higher than that of the commercial products.

Development of CAD software package of intellectualized casting technology

Based on the numerical simulation of solidification, a computer aid design(CAD) software package of casting technique was developed to design the rising system intelligently. The software can calculate the size and locate the situations of the isolated melts. According to the liquid shrinkage of each isolated melts and the standard parameters of risers in the database, the riser’s situation and the size can be identified intelligently as long as the riser’s shape is selected. 3-D software and simulation analysis of CAST soft/computer aid engineering(CAE) software show that the design of the riser and the running system is feasible.

Development of Strip Casting Technology in Rare Earth Permanent Magnet Alloys and Hydrogen Storage Alloys in China

The SC technique is now being applied widely in material preparation, especially in rare earth functional materials in virtue of its advanced process and high performance product. The applications of SC technique in rare earth permanent magnet alloys and hydrogen storage alloys were analyzed integrative, on the basis of summary of SC technique development in this paper. The paper mainly includes development history of SC technology, effect of SC technology on alloy microstructure, application of SC technology in RE storage hydrogen alloy and sintered Nd-Fe-B alloy, development of SC equipment and SC product industry. At the same time, the paper points out the existing problem of SC products.

Microstructure of Ni /WC Surface Composite Layer on Gray Iron Substrate

The surface infiltrated composite （Ni/WC） layers on gray iron substrate were fabricated through a vacuum infiltration casting technique （VICT） using Ni-based composite powder with different WC particles content as raw materials.The microstructures of surface infiltrated composite layer,the interface structures between surface composite layer and the substrate,the changes of macro-hardness with the increasing of WC content and the micro-hardness distribution are investigated.The infiltrated composite layer includes a surface composite layer and a transition layer,and the thickness of the transition layer decreases with the increasing content of WC.The thickness of transition layer with 20%WC content in the surface infiltrated composite layer was 170 μm which was the thickest for all transition layers with different WC content.The surface composite layer was mainly composed of WC,W2C,FeB and NiB,along with Ni-Cr-Fe,Ni （Cr） solid solution,Ni （Si） solid solution and Ni （Fe） solid solution.The transition layer was composed of Ni （Cr） solid solution,Ni （Fe） solid solution,Ni （Si） solid solution,Fe （Ni） solid solution and eutectic.The surface macro-hardness and micro-hardness of the infiltrated layer had been evaluated.The macro-hardness of the surface composite layer decreases with the WC content increasing,and the average macro-hardness is HRC60.The distribution of micro-hardness presents gradient change.The average micro-hardness of the infiltrated layer is about HV1000.

GPU Accelerated Marine Data Visualization Method

The study of marine data visualization is of great value. Marine data, due to its large scale, random variation and multiresolution in nature, are hard to be visualized and analyzed. Nowadays, constructing an ocean model and visualizing model results have become some of the most important research topics of ‘Digital Ocean'. In this paper, a spherical ray casting method is developed to improve the traditional ray-casting algorithm and to make efficient use of GPUs. Aiming at the ocean current data, a 3D view-dependent line integral convolution method is used, in which the spatial frequency is adapted according to the distance from a camera. The study is based on a 3D virtual reality and visualization engine, namely the VV-Ocean. Some interactive operations are also provided to highlight the interesting structures and the characteristics of volumetric data. Finally, the marine data gathered in the East China Sea are displayed and analyzed. The results show that the method meets the requirements of real-time and interactive rendering.