性能的影响
( 1. 清华大学机械工程系， 北京 100084；
2. 中国一汽 铸造有限公司，长春 130011；
3. Toyo Machinery & Metal Co Ltd, Fukusato, Futami-cho, Akashi-shi,Hyogo-ken, 674-0091, Japan)
摘 要: 以镁合金发动机缸盖罩盖为研究实例，对镁合金压铸过程中减速减压工艺对型腔内压力变化、 铸件外观质量、 铸件性能、 铸件内孔洞的影响进行了研究。 结果表明： 镁合金压铸充型过程中采用减速或减压工艺会造成型腔内充填压力降低，导致铸件表观质量下降； 分别采用减速或减压工艺， 型腔内的增压压力稍有降低， 铸件内孔洞数量和尺寸稍有增加， 铸件强度和密度随之降低； 同时采用减速和减压工艺，型腔内充填压力和增压压力显著下降， 铸件内孔洞数量和尺寸明显增加， 铸件强度和密度随之显著下降。
关键字: 镁合金； 压铸； 减速； 减压； 表观质量；性能
（ 1. Department of Mechanical Engineering,
Tsinghua University, Beijing 100084, China;
2. Foundry Ltd. of the First Automotive Works, Changchun 130011, China;
3. Toyo Machinery & Metal Co Ltd, Fukusato, Futami-cho, Akashi-shi,Hyogo-ken, 674-0091, Japan）
Abstract: A magnesium cylinder head cover was used to experimentally study the influence of application of decreasing speed technology(denoted as DST) and decreasing pressure technology(denoted as DPT) on pressure variations in the die cavity, the surface quality, properties and gas porosity of magnesium alloy die castings. The results show that the application of DST and DPT during mold filling of magnesium die casting leads to the decrease of filling pressure and the decrease of surface quality of the castings. Application of DST or DPT respectively causes the decrease of the pressure during pressure intensification stage and a little increase of the number and size of gas porosity in the castings. As a result, the tensile strength and density of the castings decrease. Application of DST and DPT simultaneously causes a great decrease of filling pressure and the pressure during pressure intensification stage and a sharp increase of the number and size of gas porosity in the castings. Accordingly, the tensile strength and density of the castings decrease greatly.
Key words: magnesium alloy; die casting; decreasing speed; decreasing pressure; surface quality; property
