標題: | THE CAST STRUCTURE OF A 7075 ALLOY PRODUCED BY A WATER-COOLING CENTRIFUGAL CASTING METHOD |
作者: | YEH, JW JONG, SH 交大名義發表 材料科學與工程學系 National Chiao Tung University Department of Materials Science and Engineering |
公開日期: | 1-三月-1994 |
摘要: | A water-cooling centrifugal casting method was applied to cast the 7075 Al alloy to generate a much finer cast structure than that produced by conventional ingot casting methods. The effects of casting parameters, i.e., rotation speed, pouring temperature, water flow, and grain refiner, on casting structure were systematically studied so that the optimum casting condition and the solidification mechanism could be established. The typical cast structure along the thickness direction of a cast ring could be divided into four equiaxed zones, including the chill zone which is in contact with the mold wall. All zones have their characteristic grain size, morphology, and relative thickness, which are all dependent on the casting condition. The optimum casting condition yielding the finest structure available was found to be 3000 rpm, 650-degrees-C, and sufficient water cooling. A uniform portion occupying 90 pct of the whole thickness and having a grain size of 17 mum could be achieved under such a casting condition. When a grain refiner was added, the whole ring became further concentrated with grains of fine structure. A mechanism concerning the overall effects of rapid solidification, turbulent flow, and centrifugal force has been proposed for the present casting method and might explain the zone-structure formation and the effects of the casting parameters on microstructural features. |
URI: | http://dx.doi.org/10.1007/BF02651606 http://hdl.handle.net/11536/2595 |
ISSN: | 1073-5623 |
DOI: | 10.1007/BF02651606 |
期刊: | METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE |
Volume: | 25 |
Issue: | 3 |
起始頁: | 643 |
結束頁: | 650 |
顯示於類別: | 期刊論文 |