微观组织结构对铂钴永磁合金磁性能的影响

Effect of microstructure on the magnetic properties of Pt-Co permanent magnetic alloy

系统研究了Pt-Co合金磁性能与其微观组织结构间的关系.合金铸锭的X射线衍射结果表明:熔炼后的Pt-Co合金铸锭沿冷却方向存在明显的织构;扫描电镜照片显示合金的组织结构为柱状晶结构,柱状晶的生长方向平行于冷却方向;合金铸锭经塑性变形和再结晶处理后柱状晶组织消失,电镜照片显示处理后的合金晶粒尺寸变小且均匀;对不同组织结构的Pt-Co合金磁性能的测试结果表明,经塑性变形及再结晶处理后合金的磁性能有了明显提高,说明该合金中晶粒尺寸和取向是影响其矫顽力的重要因素.

The relationship between the magnetic properties and the microstructure of Pt-Co permanent magnetic alloys was studied. X-ray diffraction （XRD） results indicated that the as-cast Pt-Co alloy has a texture microstructure. According to the scan electron spectrum （SEM） results,the as-cast alloy has a columnar structure and the columnar crystal grows along the cooling direction. After plastic deformation and recrystallization,the texture was disappeared and the grains became smaller and more uniform. Compared with the columnar structure of Pt-Co alloys,the magnetic properties of the recrystallized alloys were improved obviously. So the grain size and direction may be the main factors which can affect the coerivity of Pt-Co alloys.