论文部分内容阅读
利用一种改良的Bridgman技术的定向结晶制备了Co-Fe-Cu-Ce永磁合金。在低的过热温度(△T～高于熔点(1100℃左右)20℃)熔化的和以合适的速度(2. 3厘米/小时)凝固的样品产生一种相当均匀的具有择优结晶取向的柱状晶结构。C轴与长大轴之间的角度通常在15°之内。增加凝固速度得到无织构的细粒结构,降低其速度则产生不规则取向的粗大柱状晶。高的过热温度(△T～300～400℃)引起液态金属与氧化铝坩埚壁的反应并导致面心立方的富钴枝晶的形成。利用改良的Bridgman技术,已制备出具有良好磁特性的,长8厘米、直径2. 54厘米的取向样品。Co_(3. 5)Fe_(0. 5)CuCe合金于1000℃退火后再于400℃时效,其性能为:_iH_c=7000奥斯特、Br=6100高斯、(BH)_(max)=9. 2×10~5高·奥。一种Co_(3. 6)Fe_(0. 5)Cu_(0. 9)Ce合金经过类似的处理之后,其性能为:_iH_c=6000奥斯特、Br=6250高斯、(BH)(max)=9. 5×10~6高·奥。
Co-Fe-Cu-Ce permanent magnetic alloys were prepared by directional crystallization using a modified Bridgman technique. The samples which melted at a low superheating temperature (ΔT ~ 20 ° C above the melting point (about 1100 ° C) and solidified at a suitable speed (2.3 cm / h) produced a rather uniform columnar shape with a preferred crystallographic orientation Crystal structure. The angle between the C axis and the long axis is usually within 15 °. Increasing the solidification rate results in a texture-free fine-grained structure, and decreasing its velocity produces irregularly oriented coarse columnar crystals. High overheating temperatures (ΔT ~ 300-400 ° C) cause the reaction of the liquid metal with the alumina crucible wall and lead to the formation of face-centered cubic cobalt-rich dendrites. Using the modified Bridgman technique, oriented samples having a length of 8 cm and a diameter of 2.54 cm have been prepared with good magnetic properties. Co_ (3.5) Fe_ (0.5) CuCe alloy annealed at 1000 ℃ and then aged at 400 ℃, the properties are: _iH_c = 7000 Oe, Br = 6100 Gauss, (BH) _ (max) = 9 2 × 10 ~ 5 high · Austria. After a similar treatment, a Co_ (3.6) Fe_ (0.5) Cu_ (0.9) Ce alloy has the following properties: _iH_c = 6000 Oe, Br = 6250 Gauss, (BH) (max) = 9. 5 × 10 ~ 6 high · Austria.