(上海交通大學(xué) 材料科學(xué)與工程學(xué)院, 上海 200030)
摘 要: 研究了在遠(yuǎn)高于居里點(diǎn)的高溫凝固過程中磁場(chǎng)對(duì)TbFey和TbxDy1-xFey(x=0.3, y=1.9~2.0)合金取向的影響。 結(jié)果表明： 對(duì)凝固速率、 熔體溫度和材料成分的控制是在磁場(chǎng)中獲得沿易軸取向所應(yīng)考慮的； 在高于100 mT的靜磁場(chǎng)中， 直徑為16 mm的TbFe1.9和Tb0.3Dy0.7Fe1.9樣品被加熱至略高于熔點(diǎn)的溫度；當(dāng)冷卻速率低于50 ℃/h時(shí)， 可以獲得［111］的擇優(yōu)取向； 但隨著合金中Fe含量的增加， 合金中的RFe3相將出現(xiàn)， 過多的RFe3相將在包晶反應(yīng)結(jié)束后仍然留在固液相中， 從而影響晶體的取向； 當(dāng)Fe含量y≥2時(shí)， TbFey和TbxDy1-xFey在磁場(chǎng)中的慢冷條件下很難獲得［111］擇優(yōu)取向的織構(gòu)。
關(guān)鍵字: R-Fe合金； RFe3相; 凝固; 冷卻速率; 易軸; 磁場(chǎng)
（School of Materials Science and Engineering,
Shanghai Jiao Tong University, Shanghai 200030, China）
Abstract: The effect of magnetic field on the orientation of TbFey and TbxDy1-xFey(x=0.3, y=1.9-2.0) alloy during the solidification course at high temperature far above Curie point was studied. The results show that the control of solidification rate, melt temperature and chemical composition is necessary for achieving crystal alignment with orientation along the easy magnetic axis in a magnetic field. In a static magnetic field of above 100 mT, TbFe1.9 and Tb0.3Dy0.7Fe1.9 alloy were heated to the temperature of slightly above their melting point, and then solidified at cooling rate of below 50 ℃/h， the［111］ orientation would be dominant in samples. However, with increasing the content of Fe in alloy from 1.93, RFe3 phases would precipitate in alloy, excessive RFe3 phases would still exist in liquid-solid phase after peritectic reaction, then degrade the orientation degree in sample. It is difficult to obtain the preferred orientation of ［111］ direction for TbFey and TbxDy1-xFey alloy by slow cooling in magnetic field at Fe content y≥2 in alloy.
Key words: R-Fe alloy; RFe3 phase; solidification; cooling rate; easy magnetic axis; magnetic field
