金属结合不烧铝碳滑板的中温力学性能研究

Study on Middle Temperature Mechanical Properties of Aluminum Bonded Unburned Al_2O_3-C Slide Gate Plates

模拟不烧铝碳滑板配方,以板状刚玉、金属铝粉、鳞片石墨为主要原料,热固性酚醛树脂为结合剂,经混练、成型、烘干、切割、磨制成规格为25mm×25mm×130mm的试样,检测了200℃×24h烘干、500～1100℃×3h埋碳热处理后试样的高温抗折强度和应力-应变关系。借助XRD、SEM和EDS对试样进行物相组成和显微结构分析,以期对高性能滑板的开发、研制和改进提供理论依据和参考。实验结果表明:金属铝粉的熔化(熔点660℃)导致金属铝结合不烧铝碳滑板的高温抗折强度和弹性模量在700℃左右出现最低值;之后随温度的升高,金属铝发生反应生成六方状氧化铝和纤维状碳化铝,滑板的显微结构和物相组成发生明显变化,高温抗折强度和弹性模量急剧增大,1100℃时达到所测试温度范围内的最大值,并有继续增大的趋势。

Based on the formula of aluminum bonded unburned Al203-C slide gate plates, mixtures of corundum,metal aluminum,flake graphite and thermosetting phenolic resin binder were prepared, and then formed,dried,cut and finally grinded into 25 mm × 25 mm × 130 mm samples. Then the middletemperature properties of specimen after dried at 200 ℃ for 24 h and heated from 500 ℃ to 1100 ℃ buried in carbon for 3 h were determined, such as stress-strain relations, high-temperature modulus of rupture （HMOR） etc. Furthermore,the microstructure and mineral phase of the specimen were studied by scanning electron microscope （SEM） ,energy dispersive X-ray spectroscope （EDS） and X-ray Diffraction （XRD）, with a view to providing some theoretical basis and reference for the development and improvement of high-performance slide gate plates. The results showed that： The hot modulus of rupture （HMOR） and modulus of elasticity of the unburned AI203-Al-C slide gate plates were both the lowest at 700 ℃ caused by the melting of the aluminum;then they sharply increased going with the temperature rising and went to the highest at 1100 ℃ during the test temperature range,because the aluminum acted and formed hex alumina and fibrous aluminum carbide which led to tremendous changes of their microstructures and mineral phases.