Yun-Jong Kim
,
Sang-Bae Kim
,
Hyun-Hye Park
,
Myeong-Deok Seo
,
Byoung-Cheon Lee
,
Man-So Han
,
Taik-Nam Kim
,
Sung-Baek Cho
材料科学技术（英）
Generally the gold investment material consists of cristobalite, quartz and plaster. The physical property of gold investment materials depends on its thermal expansion coefficients, compressive strength, and particles size distribution. Since the thermal expansion coefficient of cristobalite and quartz are 2.6×10-6/℃ and 2.32×10-6/℃ respectively, the composition ratio of each components influence the thermal and physical properties of gold investment materials. For the clinical applications, it is necessary to improve the properties of gold investment materials such as homogeneous size distribution and thermal expansion coefficients. In the present study, effect of inorganic fillers such as cristobalite and quartz on gold alloy investment was investigated to improve the properties of it. The compressive strength and thermal expansion coefficients of the specimens were evaluated. The results showed that cristobalite and quartz were homogeneously distributed by milling. The optimum compressive strength was obtained at the ratio of 42:22 cristobalite and quartz, respectively.
关键词:
Investment
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null
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null
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null
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null
隋普辉
,
陆雷
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2009.06.009
采用DTA、XRD、SEM等分析了锂锌铝硅(LZAS)系微晶玻璃的析晶及热学和力学性能.结果表明:610℃时析出晶体γ_Ⅱ-LZS,为0.2μm的树枝状;650℃时出现直径为0.5μm的球状方石英晶粒,随后晶粒消失;720℃之后开始析出蜂窝状网络结构β-石英固溶体,并且γ_Ⅱ-LZS逐渐转化为γ_0-LZS晶体;8500C时β-石英固溶体转变为均匀的颗粒状β-锂辉石固溶体,直径为1 μm.试样的线胀系数随晶化温度先增大再减小后趋于平稳,而试样的弯曲强度先减小再增大后趋于平稳,其变化规律依赖于晶化过程中产生的晶相的种类以及含量.
关键词:
微晶玻璃
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析晶
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线胀系数
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弯曲强度
袁剑民
,
冯艳荣
,
吴振军
,
王彦军
,
李丝雨
,
孙萍
新型炭材料
利用酚醛树脂粘接短切炭纤维,炭化得到全炭型的稳固炭纤维网络增强体(CFNR),真空浸胶后制得一种低膨胀、高刚性的CFNR/聚丙烯(PP)复合材料.利用扫描电镜和热机械分析仪对CFNR/PP复合材料的微观结构和热机械性能进行表征.结果表明,在相同的载荷条件下,常规短切炭纤维(SCF) /PP复合材料的形变是CFNR /PP复合材料的2.3倍.相同温度下,CFNR/PP复合材料、SCF/PP复合材料和PP的储能模量和弯曲模量都依次下降.在30 ℃和110 ℃时,CFNR/PP复合材料的弯曲模量分别为SCF /PP复合材料的1.8倍和2.5倍.而且,CFNR/PP复合材料具有较高的热尺寸稳定性,其平均热膨胀系数(30~120 ℃)是SCF /PP复合材料的1/4.可见,与松散的短切炭纤维网络增强结构相比,CFNR在提高聚合物复合材料的刚性和热尺寸稳定性方面更有效.
关键词:
炭纤维网络增强体
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热机械性能
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刚性
,
模量
,
热膨胀系数
陈书华
,
韩建平
,
王喜占
,
刘新东
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2016.04.012
利用浸渍法制备连续碳纤维增强聚醚醚酮(CF/PEEK)预浸带,对其成型温度、行进线速度进行研究,并测试了CF/PEEK预浸带的热胀系数、拉伸性能,利用SEM扫描电镜观察CF/PEEK预浸带内部界面结合状态.结果显示,预热区、熔融热压区温度分别控制在110～ 130℃和220～370℃,预浸带行进线速度控制在2 m/min时,制备的预浸带性能较好;在-150 ～+ 150℃范围内,CF/PEEK预浸带线胀系数为0.5×10-6/K,并随着纤维体积分数增大而减小;CF/PEEK预浸带最大拉伸强度达到1.81 GPa;SEM扫描电镜显示碳纤维与PEEK界面结合良好.研究显示,CF/PEEK预浸带制备工艺参数可行,CF/PEEK预浸带性能较好,具有工程应用价值.
关键词:
CF/PEEK
,
预浸带
,
碳纤维
,
线胀系数
