Correlation of magnetic and mechanical properties with microstructure in Fe/Co/2-3 pct V alloys

Remendur is an alloy of approximately equal proportions of iron and cobalt with two to four wt pct vanadium. In previous articles by the authors, various aspects of the ternary phase equilibrium and the influence of processing variations on microstructure were described. This paper reports on the more complete correlation among microstructure, mechanical properties, magnetic properties, and resistivity. For strand annealed (900 to 950°C) material, the mechanical properties are only a weak function of annealing temperature but a strong function of vanadium content. Subsequent annealing at 600°C significantly increases the yield and tensile strengths but the mode of fracture becomes brittle cleavage, in contrast to the ductile failure of strand annealed material. Coercivity in the strand annealed (900 to 950°C) and quenched condition is primarily determined by grain size and transformation strains produced during the quench. Coercivity in 600°C annealed material is due to the fine dispersion of stable γ particles in the α′1 matrix which are impediments to domain wall motion. In general, resistivity is relatively independent of processing temperature.     

粉末特性对Sm2(Co,Cu,Fe,Zr)17永磁材料及性能的影响

在粉末冶金工艺生产Sm2(Co,Cu,Fe,Zr)17的过程中,粉末特性对材料的性能存在较大影响.本研究对气流磨和滚动球磨两种工艺所制备的粉末进行比较,通过粒度分析及显微镜观察,研究了粉末的粒径与形状对材料性能的影响.分析结果表明,气流磨所制备的粉末平均粒径为4.53μm,尺寸分布范围较窄,粉末颗粒成近似球状,所得材料磁性能参数中Br,(BH)max优于滚动球磨.