The effect of stirring during solidification on the microstructure of Al-2 mass%Si alloys was investigated. Stirring was carried out by two methods.
1) Stirred just after pouring until 50 % solidified, then water-quenched.
2) Stirred just after pouring until 50 % solidified and stirred for 30, 60, 180, 300, 500 and 1000 seconds, then water-quenched.
  In experiment 1), the primary grains at higher cooling rates were finer than those of lower cooling rates. In addition. the roundness factor of primary grains increased in accordance with the stirring time.
  In experiment 2). the size of primary grains increased in accordance with stirring speed.

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  Critical length and diameter of riser neck experimentally determined by G. Sciama for a cylindrical sand casting of three different alloys were successfully reproduced by numerical solidification simulation. As shown by Sciama, the critical diameter is dependent on the neck length and on the cast alloy. Numerical simulation indicated the presence of a critical neck length below which directional solidification is realized with a neck of a minimum diameter. Effects of riser size, casting size and superheat were also examined. A more or less reasonable neck size can also be obtained by conventional design rules. But there is a room for further effort by pursuing the optimum size.

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  Solidification structures and frictional wear characteristics of high P cast iron containing 3.3 mass%C, 1.7 mass%Si, 1.4 mass%Mn, 0.3-3.0 mass%P, 0.37 mass%Cr, 0.20 mass%V were examined with an image analyzer and original braking test machine. High P cast iron consists of steadite, eutectic cementite and flaky graphite distributed in pearlitic matrix. The addition of higher levels of P increases the steadite, which raises frictional wear resistance against the wheel steel.The wear resistance effectively improved with the addition of about 0.6 mass%P. The braking ability also improved with the addition of more than 1 mass%P at the initial braking speed of above 15 m/s. The contact surface was heated above 990 K at the initial braking speed of 25 m/s and the steadite partially melted or softened, which enhanced the braking ability of cast iron.

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  Special knowledge is needed in foundry shops. Especially, know-how on the diagnostics of casting defects is very important. Usually many companies have considerable documents on casting defects but it is still not clear now to use them effectively. The recent IT environment enables accumulation of such dicuments as electronic data naturally. In this study, a method to analyze and categorize document data on casting defects was developed using text-mining technology and knowledge map. Namely, delegate words for each casting characteristic are grouped and located on a two-dimensional map. Words related to the documents are highlighted on the map. This method enables visualization of the results of document classification, and has been found to be useful for classifying and retrieving documents to casting engineers.

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  In this research, the effects of steel can scrap use rate in spheroidal graphite cast iron were investlgated. Used steel cans were made by two kinds of processes ; one consisting of only pressing, and another which removes the Al-Mg alloy of the can-top to some extent by magnetic-selection treatment after the shredder process. The research results were as follows.
  At a steel can use rate of 80%, the Al content of pressed cans was 4.25%, and that of shredder-processed cans was 1.72%. Cr and Sn increased with the use of the pressed cans and shredder-processed cans, but Ti increased only with pressed cans. Tensile strength and hardness increased with the increment in the use rate of steel cans. When the use rate of pressed cans exceeded 10%, elongation decreased abruptly. And when that of shredder-processed cans exceeded 40%, elongation decreased abruptly. It was also found that compacted vermicular graphite appeared at a use rate of 20% for pressed cans, and 80% for shredder-processed cans. On the other hand, Al-Fe-C ternary compound generate appeared from a use rate of 40% for pressed cans, and 80% for shredder-processed cans.
  The above results showed that pressed cans could be used to 10% as the dissolution material of electric furnaces and shredder-processed cans to 40%.

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