(哈爾濱理工大學 材料科學與工程學院，哈爾濱 150080)
摘 要: 利用自行研制的交替變向電磁場凝固裝置， 采用對比實驗方法研究了交替變向電磁場對Al-5%Cu合金晶粒度、 集中縮孔、 分散縮孔和縮松以及致密度的影響規(guī)律及機理。 結果表明： 交變電磁場對Al-5%Cu合金晶粒形貌和晶粒尺寸產(chǎn)生明顯的影響； 隨著磁場強度的增加， 合金晶粒形貌由粗大的柱狀晶轉變?yōu)榧毿〉牡容S晶，晶粒尺寸由30.2 mm降低到0.2 mm； 在0.2 T強場下試樣集中縮孔相對深度縮小了10倍左右， 分散縮孔和縮松數(shù)量明顯減少，鑄件的致密度提高了2.9％。
關鍵字: Al-5％Cu合金; 交替電磁場; 集中縮孔; 縮松
in Al-5%Cu alloy
（ School of Materials Science and Engineering,
Harbin University of Science and Technology,Harbin 150080, China）
Abstract: Effects of alternating electromagnetic field on the grain size, concentrating shrinkage cavity, dispersing shrinkage porosity and density of Al-5%Cu alloy were investigated by comparative methods using self-made alternating electromagnetic field apparatus. The results show that the alternating electromagnetic field has a significant effect on the grain morphology and grain size of Al-5%Cu. The grain morphology is changed from a very big columnar structure to a fine equiaxed one and the grain size is decreased from 30.2 mm to 0.2 mm with the increase in alternating electromagnetic field intensity. The depth of concentrating shrinkage cavity is decreased about ten times when magnetic intensity is 0.2 T. The volumes of both dispersing shrinkage cavity and shrinkage porosity are reduced, leading to the increase in alloy density about 2.9%.
Key words: Al-5%Cu alloy; electromagnetic field; concentrating shrinkage cavity; shrinkage porosity
