【作者】 于青玉；

【导师】 袁子洲；

【作者基本信息】 兰州理工大学 ， 材料加工工程， 2014， 硕士

【摘要】 消失模涂料是消失模铸的关键技术,石英基消失模涂料因其价格低廉,原料易得得到了广泛的应用。但是石英基消失模涂料存在烧结性能差的缺点,本文旨在通过在石英基消失模涂料中添加助烧剂的方法,改善石英基涂料的烧结性能,使之具有高耐火度低烧结点的特性。本文通过单因素梯度法,研究了云母粉、滑石粉、钾长石粉、钙长石粉对石英基消失模涂料烧结性能的影响。配制不同助烧剂含量的涂料,并制作成标准试样,将试样在1300℃、1350℃、1400℃、1450℃、15000℃、1550℃下进行烧结。将烧结后的试样进行抗弯强度试样,分析助烧剂含量对涂料烧结后抗弯强的影响。对烧结后试样进行显气孔率、体积密度的测试,分析烧结后试样的烧结程度与助烧剂含量及温度的关系。对烧结后的试样进行SEM分析,观察不同助烧剂含量、不同温度下试样内部的微观形貌,分析助烧剂对涂料烧结性能的影响。对烧结后试样进行XED分析,通过分析涂料烧结后的内部组成,并结合相图分析助烧剂对试样烧结性能的影响。得出如下结论：助烧剂的加入使试样的抗弯强度增加,在试验添加量下,云母粉试样、滑石粉试样、钾长石粉试样、钙长石粉试样的抗弯强度分别从3.2MPa-5.8MPa增加到4.3MPa-10.6MPa、8.4MPa-14.6MPa、9.3MPa-14.3MPa、7.3MPa-14.2MPa。助烧剂的加入使试样的显气孔率减小,在试验添加量下：云母粉试样、滑石粉试样、钾长石粉试样、钙长石粉试样的显气孔率,分别从59.6724%～65.2638%减小到27.1186%～57.2864%、27.1186%～57.2864%、41.3249%～54.9674%、44.5.87%～63.1579%。助烧剂的加入使试样内部组织更加致密,随着助烧剂添加量的增加试样内部的液相量增加,试样内部结构更具整体性。助烧剂的加入降低了试样的熔点,促进了试样在烧结过程中内部的化学反应。随着助烧剂加入量的增加,试样内部成分趋于复杂。所以说助烧剂的加入使涂料的烧结程度得到了明显的改善。虽然各助烧剂的作用效果存在一定的差异,但各助烧剂的加入,均使得涂料具有了高耐火度低烧结点的特性。更多还原

【Abstract】 Lost foam casting coating is the key technology of LFC casting. Quartz based LFC coating due to its low price and easy to get have been widely used. But the quartz based LFC coating have the poor performance in sintering. In this paper we used sintering aids to improve the Sintering Property. In order to make coating have the property of high refractoriness and low sintering temperature.In this paper we study the effect of mica powder, talc, potassium feldspar powder, calcium powder on sintering property through the single factor gradient method. Different content sintering aids were prepared by coating and made into standard samples. The samples were sintered at six different temperature. After sintered the simple was taken test of bending strength, in order to analysis the influence of the sintering aids to bending strength. Mature the apparent porosity, bulk density of the simples to analysis the relationship between sintering degree and sintering aids and temperature. The SEM analysis was taken to make out the influence of aids to the internal microstructure. Do the XED analysis of sintered samples, through the analysis of internal coating after sintering and combined with the phase diagram analysis the effect of sintering agent on sintering properties.Finally obtained the following conclusions:The sintering aids increased the bending strength, at the test additive amount the bending strength of the sample respectively increased from to3.2MPa～5.8MPa to4.3MPa～10.6MPa、8.4MPa～14.6MPa、9.3MPa～14.3MPa、7.3MPa～14.2MPa.The sintering aids decreased the apparent porosity of the sample, the figure decreased from59.6724%～65.2638%to27.1186%～57.2864%、27.1186%～57.2864%、41.3249%～54.9674%、44.5.87%～63.1579%。The aid of sintering aids make the microstructure of the sample more densification. With the increase of the aids there are more liquid phase and more integrity.The sintering aids decreased the melting point of the sample make it more easily to chemical reaction. More aids make the component more complex.So we can say that the aid of the sintering aids improved the sintering property of the coating. Although the different aids have the different effect, but they all make coating have the property of the high refractoriness and low sintering temperature.更多还原