摘要
电磁约束成型中感应圈的约束行为研究＊沈军①李金山①李建国②傅恒志②如何将许多合金、诸如高温合金、钛合金、金属间化合物等化学活性很强的材料熔化为高纯净、高质量的熔体并成型成表面光洁性能优越具有复杂截面形状部件的电磁约束成型技术越来越引起人们的关注［１］...
Large induction coil (100～200 cm in diameter) has been employed in the U.S. and Switzerland for quantity production of high quality casting, using the electromagnetic confinement process. Blades of aircraft jet engines are however small in size. We now present our findings on the behaviour of small induction coil necessary for producing high quality engine blades, using the electromagnetic confinement process. The distributions of magnetic flux densities of two kinds of induction coil with a trumpet inside wall(coil 1 in Fig.2) and with a vertical inside wall(coil 2 in Fig.2) have been measured precisely by means of a detection coil and a position system. The shaping process was observed carefully during experiments. The shape and size of liquid metal meniscus were determined by measuring the quenched metal meniscus under electromagnetic pressure. In both kinds of induction coils the shapes of cross section of meniscus were determined mainly by the isograph of magnetic flux density, but at some points on surface where the curvature radii were quite small, due to the influence of surface tension, the shape of cross section always deviated from the isograph of magnetic flux density, especially for some metals that can form strong oxide film(as shown in Fig.1). By comparing the induction coil with a vertical inside wall(as shown in Fig.2) with the induction coil with a trumpet inside wall (as shown in Fig.2), we found that the latter had a steeper distribution of magnetic flux density along axis. The electromagnetic pressure acting on the surface of liquid metal meniscus with a vertical periphery was nearer to the static pressure produced by liquid metal column at every point, so the vertical periphery of liquid metal could be maintained. The vertical periphery of meniscus ensured the following advantages:uniform cross section, smooth surface, good coupling with temperature field and steady processing. In this kind of coil the maximum magnetic flux density was at the bottom; thus it was easier for the inductio
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
1997年第1期156-158,共3页
Journal of Northwestern Polytechnical University
基金
国防科工委95重点项目资助
关键词
电磁约束成型
感应圈
约束行为
金属材料
electromagnetic confinement, electromagnetic pressure, magnetic flux density
