Stress Whitening Quantification of Thermoformed Mineral Filled Acrylics
Stress Whitening Quantification of Thermoformed Mineral Filled Acrylics
复制标题
热成型矿物填充丙烯酸树脂的应力致白定量
DOI：
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发表时间：
2010
期刊：
影响因子：
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通讯作者：
C. Basaran
中科院分区：
文献类型：
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作者：
E. Gunel;C. Basaran
Stress whitening problem in thermoformed alumina trihydrate (ATH) reinforced poly(methyl methacrylate) (PMMA) was studied. In situ heavy-gage thermoforming of acrylics was entirely replicated under laboratory controlled conditions at different operation parameters. Samples were monitored with optical microscope after the completion of the thermoforming operation. For stress whitening quantification, a new index was proposed from image histograms of processed optical micrographs. Results indicated that stress whitening in PMMA/ATH samples increases with level of plastic deformation at all thermoforming conditions. The influence of the forming rate and forming temperature on the degree of stress whitening was explained in terms of change in material behavior and microdeformation mechanisms around two characteristic temperatures of PMMA/ATH. Developed method for stress whitening quantification characterizes different levels of stress whitening with single numeric values. It is shown that stress whitening index and density of microdeformation features display a strong correlation. Higher density of particle cracks at low forming temperatures results in higher stress whitening levels. Increased surface irregularity and large size voids at high forming temperatures produce lower stress whitening.
