Atsuhito Honda
,
Masaki Kawano
,
Masyoshi Ishida
,
Kejji Sato
,
Michiro Komatsubara
,
Isamu Ohyama
材料科学技术（英文）
The performance of a 3-phase 6-pole 400 W inverter-drive induction motor was investigated using a variety of non-oriented electrical steels for stator core at PWM inverter fundamental wave frequencies of 30 to 300 Hz. There existed an optimum Si content of the material depending on the tooth flux density. Both reduction of material thickness and stress-relief annealing of the stator core improved the motor efficiency. The influence of Si content on the efficiency was small at lower PWM frequencies, while at higher frequencies the motor efficiency increased with increasing Si content. The Cu loss W-c increased and the Fe loss W-i counteractively decreased with increasing Si content at lower frequencies, while at higher frequencies W-i had dominant effect on the efficiency. Newly developed materials RMA, having lower Fe tosses after stress-relief annealing and higher flux densities with lower Si contents, showed motor efficiencies superior to conventional JIS grade materials with comparable Fe losses.
关键词:
田兴
,
张彦生
,
师昌绪
金属学报
在Fe-Mn-Al-Cr系亚稳奥氏体区内,用膨胀法测定了40种合金的γ→ε-马氏体转变温度M_(es)。以多元线性回归方法处理实验结果,建立了M_(es)与合金成分关系的经验公式。经验公式中,1Wt-％的Al,C,Cr分别使Fe-Mn合金的M_(es)降低约51,339,8℃;这个结果与以前研究它们对Fe-Mn合金γ→ε-马氏体转变的影响和Ishida计算它们对Fe-Mn合金γ→ε相变驱动力的影响一致。根据γ→ε-马氏体转变的层错机制,简要讨论了Al,C和Cr对Fe-Mn合金M_(es)的影响。
关键词:
温伟
,
王彪
,
王华平
材料导报
采用原位聚合法制备了碳纳米管/聚丙烯腈(CNT/PAN)复合材料,用MDSC的测试方法研究了复合材料的热性能,并由此推导了复合材料的热导率.应用Cheng-Vachon、Nielsen-Lewis和Okamoto-Ishida 3种导热理论模型对CNT/PAN复合材料的热导率进行估算.对比实验测试与导热理论模型的计算结果,考虑到碳纳米管在聚合物基体中的分散和取向情况,得出Nielsen-Lewis理论在低填充含量及室温条件下可以较准确地估算无规分散的CNT/PAN复合材料体系的热导率.
关键词:
碳纳米管/聚丙烯腈复合材料
,
导热理论模型
,
热导率
,
比热容
陶果
,
杨刚
高分子材料科学与工程
以4-氨基苯基马来酰亚胺、甲醛、苯酚为原料,采用两步法经中间产物三嗪(TMIPT)合成苯并(口恶)嗪(MIPB),并借助红外光谱(FT-IR)、核磁共振(1H-NMR)和元素分析(EA)等手段对产物MIPB进行了表征.通过差示扫描量热(DSC)、FT-IR和热重分析(TGA)对MIPB的热行为进行了研究,结果发现,MIPB化合物的熔点为113.3℃,相比于Ishida报道的MIB化合物147℃的熔点降低了33.7℃,MIPB在150℃的固化率大大增加,固化后的MIPB树脂5%热失重温度T5为348℃,10%热失重温度T10为368℃,800℃残炭率达到55.6%.
关键词:
4-氨基苯基马来酰亚胺
,
苯并(口恶)嗪
,
热固性
,
高性能聚合物
