與SmCo相比, 釹鐵硼由於性能好、成本相對較低以及對環境的負面影響小, 因此是最被廣泛使用的永磁材料. 然而, 經由3D列印以增加產量而生產的NdFeB仍然需要高溫處理, 這使其在商業上不可行.
在這項研究中, 冷燒結過程將應用於使用不同酸度的添加劑. 燒結過程是由於酸性溶液和壓力的存在而發展的. 為了確定微波輻射是否可以產生磁性並表現出良好的磁性質, 在冷燒結過程之後還進行了微波退火.
密度測量結果顯示, 在室溫下以1 MPa的酸溶液燒結的NdFeB MQP-S-11-9含有 3mL, 5mL, 7mL, 和 9mL 的草酸和 10mL 的硫酸分別顯示出 77.9％, 81.79 ％, 84.07％, 85.47 ％ 相對密度. 用7mL草酸樣品達到的最佳磁性能. 經過兩階段微波退火, 第一階段是200W持續5分鐘, 重複兩次, 而第二階段是400W持續10分鐘, 重複六次後, 剩磁, 矯頑力和能量密度分別增加到 0.836T, 388.7kA/m, 和 101. 1kJ/m$^3$. MQU-F與微波退火的結合也增強了磁性能. 因此, 本研究中使用的低壓和低溫使其有可能用於進一步的3D應用.

NdFeB is the most widely used permanent magnet material because of its good performance, relatively low cost and low negative impact to the environment compared to SmCo. However, producing NdFeB by 3D printing to increase the production still needing high temperature processing which makes it impractical for commercial use.
In this study, cold sintering process will be applied to using different acidity of additive. The sintering is process developed by the existence of acidic solution and pressure. The microwave annealing also performed followed the cold sintering process with the aim of determining if microwave radiation can generate the magnetism and exhibit good magnetic performance.
The density measurement shows that NdFeB MQP-S-11-9 sintered at room temperature with 1 MPa with acid solution contain 3mL, 5mL, 7mL, and 9mL of oxalic acid with 10mL of sulfuric acid exhibit 77.9\%, 81.79\%, 84.07\%, 85.47\% relative density, respectively shows the best magnetic properties reached by sample with 7mL oxalic acid. The remanence, coercivity, and energy density were increased respectively to 0.836T, 388.7kA/m and 101.1 kJ/m$^3$ after two step microwave anneling first step 200W for 5minutes for two times repetition and second step 400W for 10seconds for six times repetition. The combination of MQU-F together with microwave annealing also enhanced the magnetic properties. Therefore, the low pressure and temperature used in this study make it possible to be used for further 3D application.

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