定向凝固Fe83Ga15Al2合金的结构及磁致伸缩性能

Structure and magnetostriction performance of directionally solidified alloy Fe_(83)Ga_(15)Al_2

系统研究不同定向凝固速率下Fe83Ga15Al2合金的相组成和磁致伸缩性能.结果表明,经过区熔定向凝固后,Fe83Ga15Al2合金的晶粒尺寸与铸态相比要大得多.当凝固速率较高时,晶粒没有明显的取向性,而当速率较低时,显示出沿轴向的取向性,同时也存在很多横向亚晶界.铸态的Fe83Ga15Al2合金在经过区熔定向凝固之后,磁性能有大幅度提高,低场响应快,且磁致伸缩值增大,凝固速率v=10μm/s时,磁致伸缩系数达到最大值53×10-6;当v=300μm/s时,λ值略低,为50×10-6,但其低场响应迅速,在50kA/m时就达到最大值.

Structure and magnetostriction of alloy Fe83Ga15Al2 were systematically studied by means of directional solidification with various solidification rate.The result indicated that,after directional solidification,the crystalline grains of alloys were greatly coarser than in as-cast.When the solidification rate was higher,the grains would not show noticeable trendency to orienting;when the rate became lower,the trendency to orienting would be in the longitudinal direction and meantime,many crosswise subgrain boundary would appear.The magnetostriction of as-cast alloy Fe83Ga15Al2 would be increased to a great extent after directional solidification and its low-field response was fast.The magnetostriction value would also be increased.The magnetostriction coefficient（λ） would reach its maximum as 53×10-6.When the solidification rate was 10 μm/s;When the solidification rate was 300 μm/s,the value of λ was lower a little bit as 50×10-6.But its low-field response was fast,reaching its the maximum as 50 kA/m.