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将氧化镁和氧化铁制成磷酸盐粘结剂自硬砂用复合固化剂,并研究了自硬砂的相关性能.结果表明,使用MgO-Fe2O3复合固化剂可以使磷酸盐粘结剂自硬砂具有较高的硬化强度,较长的可使用时间,较好的硬化特性,以及良好的溃散性.复合固化剂中Fe2O3含量为15%时,硬化强度为0.66MPa,tk/tt值为0.36. 相似文献
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高强钢板热冲压成形工艺参数是影响成形零件质量的关键因素.建立了U形件的热冲压有限元模型,采用热力耦合数值模拟得到了热冲压过程中板料的温度、厚度及应力的分布规律.并在此基础上,利用正交试验,研究了热冲压过程中板料初始温度、模具初始温度、冲压速度、压边力4个工艺参数对U形件成形后的最低温度和最大应力的影响程度.结果表明,板料初始温度的影响最大,随着板料初始温度的下降,U形件成形后的最低温度下降,最大应力值大幅度上升;模具初始温度的变化对U形件成形后的最低温度和最大应力值的变化影响最小;冲压速度的影响较大,随着冲压速度的减小,U形件成形后的最低温度下降,最大应力值上升;压边力的变化不影响板料与模具之间的传热,随着压边力的减小,U形件成形后的最低温度和最大应力值相应减小且变化范围较小. 相似文献
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J.- M. Chiou B.- Y. Wei C.- M. Chen 《Journal of Materials Engineering and Performance》1993,2(3):383-392
The use of binders in fabricating ceramic fiber preforms is essential when producing metal-matrix com-posites via squeeze
casting or liquid metal infiltration. The binder is not only used to stabilize the shape of the preform, but also to increase
its strength. A strong preform is needed to make a net shape or near-net shape casting so that many post-machining processes
can be reduced or eliminated. However, very lit-tle attention has been paid to preform fabrication, subsequent processing,
and its characterization. This work focuses on the relation between preform processing (selection of binder, heat treatment
of the pre-form, etc.) and the properties of the resulting preforms. Silica and phosphate binders were used to make short
alumina fiber preforms. The use of binders and the heat treatments used were correlated to the properties of the resulting
preforms. The results showed that the heat treating temperature, as well as the amount of binder, is relevant to the resulting
properties of the preform. Correlations among the use of binders, heat treatment condition, composition of the binders, and
the properties of the preforms were investigated. 相似文献
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介绍了4 # 复合改性水玻璃粘结剂的配方及特点;通过试验和分析,确定出取代合脂芯砂的配方和性能; 讨论了代替树脂热芯盒法制芯的可能性及芯砂配方;探讨了该粘结剂的改性机理。 相似文献