X.L. Xu
,
Z.W. Yu
,
S.J. Ji
金属学报(英文版)
Decomposition processes of the quenched Zn-Al alloys were studied by differentiai scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the stabilities of supersaturated solid solution (SSS) of Zn-Al alloy and c' phase formed by quenching would reduce with increasing Zn content and precipitating η-Zn phases even when aging at ambient temperature,so that exothermic precipitation peak in DSC curve would disappear. The activation energy of the η-Zn precipitation and their reaction enthalpy were calculated and measured. The kinetics of α' decomposition or η-Zn formation was determined by XRD.The microstructure change during aging was observed by TEM.
关键词:
differential scanning calorimetry (DSC)
,
null
,
null
,
null
曹新鑫
,
罗四海
,
何小芳
,
阎新萍
,
戴亚辉
机械工程材料
以纳米氧化锆(ZrO2)作为成核剂改性线性低密度聚乙烯(LLDPE),采用差示扫描量热仪(DSC)研究了含不同ZrO2质量分数的纳米ZrO2/LLDPE复合材料的非等温结晶行为,并分析了基于Jeziorny理论和莫志深理论的结晶动力学参数,利用Kissinger法和Takhor法计算了结晶活化能.结果表明:纳米ZrO2的加入使结晶速率变慢,阻碍了晶粒的生长;与LLDPE相比,当纳米ZrO2质量分数为10％时,复合材料的活化能降低,纳米ZrO2在结晶过程中起到异相成核的作用;而纳米ZrO2质量分数为5％时,复合材料的活化能增大,纳米ZrO2的异相成核作用不明显.
关键词:
线性低密度聚乙烯
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纳米氧化锆
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差示扫描量热分析
,
非等温结晶动力学
郭菲
,
王静静
,
朱娜琼
,
鲁晓刚
上海金属
为了测定Ni-Nb及Ni-Cu系合金中fcc相的热容,制备了4个合金样品,分别是(原子分数)Ni-4％ Nb、Ni-8％ Nb、Ni-8％ Cu和Ni-15％ Cu,1 200℃保温7天后水淬得到fcc相.采用差示扫描热分析法(DSC)和高温量热仪(96lineMHTC)测得Ni-Nb及Ni-Cu系合金fcc相在100 ～1 250℃的热容.研究表明,试验测得的热客和利用热力学数据库计算得到的热容吻合度很高,但当温度低于400℃时,两者数据相差较大,故在低温区仍需补充试验.
关键词:
Ni-Nb体系
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Ni-Cu体系
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fcc相
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热容
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差示扫描热分析法
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高温量热仪
