(上海大學(xué) 材料科學(xué)與工程學(xué)院， 上海 200072)
摘 要: 根據(jù)物質(zhì)在梯度磁場(chǎng)中的受力與其磁性相關(guān)的原理， 提出了通過(guò)測(cè)定合金在磁場(chǎng)中的受力來(lái)了解其相變的方法。 根據(jù)該方法， 對(duì)Bi-Mn合金在不同磁場(chǎng)強(qiáng)度下包晶相變點(diǎn)進(jìn)行了測(cè)定， 并從熱力學(xué)上分析了強(qiáng)磁場(chǎng)對(duì)相變點(diǎn)的影響。 結(jié)果發(fā)現(xiàn)： 隨磁場(chǎng)強(qiáng)度的提高， 合金的包晶相變點(diǎn)逐漸提高， 在10 T磁場(chǎng)下， 相變點(diǎn)提高20 ℃左右。 同時(shí)， 強(qiáng)磁場(chǎng)的施加促進(jìn)了MnBi相的形態(tài)由塊狀向片狀的轉(zhuǎn)變。
關(guān)鍵字: 強(qiáng)磁場(chǎng); 包晶相變; Bi-Mn合金; 磁化; 磁力
DENG Kang, ZHUANG Yun-qian, XU Kuang-di
（ School of Materials Science and Engineering, Shanghai University,
Shanghai 200072, China）
Abstract: Based on the relationship between the magnetization force of substance in a gradient magnetic field and its magnetic permeability, a method to detect phase transformation of metal by means of measuring the force was proposed. By this method, the 355 ℃ peritectic transformation of Bi-Mn alloys in a high magnetic field was measured, and thermodynamics analysis was carried out to investigate the influence of the magnetic field on the phase transformation. It is found that with the increasing magnetic field the transformation temperature increases significantly, and with 10 T field the increasement of the temperature reaches 20 ℃. The high magnetic field promotes the transformation of the morphology of the MnBi phase from cubic to flake.
Key words: high magnetic field; peritectic transformation; Bi-Mn alloy; magnetization; magnetic force
