Welding for permalloy is potentially applied in forming of permalloy devices in large volume and complex shape. The key point for permalloy welding is to guarantee the soft magnetic properties of joint. The new method of directionally solidified electron beam welding is conducted to optimize soft magnetic properties of 1J85 welded joint achieved by changing the direction of temperature gradient. The growth orientation of columnar crystalline clusters deflects from the original direction perpendicular to the fusion line to that towards weld center, corresponding to the direction of external magnetic field. The initial permeability is consequently increased from 3.54 mH/m (67% of the annealed 1J85) of the ordinary welded joint to 5.86 mH/m (higher than that of annealed 1J85) with the 14% decreased coercivity. The cooling rate of the weld is decreased from 12.5 * 10³ ℃/s to 9.7 * 10³ ℃/s, favorable for the growth of cellular grains and the consequently easier movement of magnetic domain boundary during magnetization process. The cellular grain boundary is proved to be element segregation instead of the conventional dislocation-walls in view of the distribution of low-angle grain boundaries. The alleviated distortion deriving from the decrease in stress is the underlying cause of the optimization of magnetic properties.

坡莫合金焊接在大体积和复杂形状坡莫合金器件的成型中具有潜在的应用价值。坡莫合金焊接的关键是保证接头的软磁性能。采用定向凝固电子束焊接新方法，通过改变温度梯度方向来优化1J85焊接接头的软磁性能。柱状晶簇的生长方向由原来垂直于熔合线的方向向焊缝中心方向偏转，对应于外磁场的方向。因此，初始磁导率从普通焊接接头的 3.54 mH/m（退火 1J85 的 67%）增加到 5.86 mH/m（高于退火 1J85），矫顽力降低了 14%。³ ℃/s 至 9.7 * 10 ³ ℃/s，有利于细胞晶粒的生长，磁化过程中磁畴边界更容易移动。从小角度晶界的分布来看，蜂窝晶界被证明是元素偏析，而不是传统的位错壁。应力降低导致的变形减轻是磁性能优化的根本原因。