回火处理对<110>取向TbDyFe超磁致伸缩材料冲击韧性的影响

EFFECT OF TEMPERING TREATMENT ON IMPACT TOUGHNESS OF<110> ORIENTED TbDyFe GIANT MAGNETOSTRICTIVE MATERIAL

采用区熔定向凝固的方法制备了<110>取向的TbDyFe超磁致伸缩合金,在800—1080℃分别进行2h的回火处理,研究了回火处理对TbDyFe合金冲击韧性、断口形貌的影响.结果表明:在800和1080℃回火处理时合金的冲击韧性最好;高于共晶温度的回火处理,冲击韧性随着回火温度的提高而增加.回火处理引起富稀土相形态、尺寸、分布的变化是导致冲击韧性变化的主要原因,TbDyFe材料的断裂为解理断裂.

The （110） oriented rods of TbDyFe giant magnetostrictive alloy have been prepared by zone melting directional solidification method. A tempering treatment for 2 h at 800-1080℃ has been carried out in an argon atmosphere. The effect of tempering on mechanical property and fractography of the rod has been studied. It was found that the largest impact toughness was achieved when tempered at 800 and 1080℃, when the tempering temperature was higher than the eutectic temperature, the impact toughness was improved with tempering temperature increasing. The change of mechanical property is due to the alternation of morphology, size and distribution of rare earth-rich phase during tempering, and the fracture of the rod is cleavage fracture.