Dependence Of Irregularity On Glossiness Of Stone Surface

With the development of economy and the improvement of people's living standards in our country, the interior and exterior decoration tends to be high-grade and luxurious, and the requirement for high-grade stone productions increases widely every year. Therefore, to improve the surface glossiness after fine grinding and polishing is the key to enhance the grade of stone productions.Based on the researches at home and abroad on the forming mechanism of the gloss surface of stones, and combined with the research development on machining technologies of ceramics and glasses, in this thesis two methods, loose abrasive polishing and ELID lap grinding, are applied for stones to achieve high-quality surface, and keep trace of transformation of the surface morphologies by multi-kinds of test technique. Ultimately the formation of surface glossiness and its dependence on surface micro-irregularity are researched by combining with the characteristics of stones. This thesis is separated into six chapters. Some basic characteristics of stones are introduced and current researches at home and abroad on the grinding and polishing mechanism of stones are summarized in chapter one; and the relationship between the micro-appearance and the surface glossiness after polishing is discussed from chapter two to chapter six, which is the main content for this thesis.The main achievements of this thesis are summarized as follows:1. The surface roughness of stone is very discrete, whose value in a place is 3-4 times as large as that in other places. After observation of the stone micro-appearance after polishing, it is found that some flaws, such as craters, cracks, crystal boundaries and pull-out pits, exist on the stone surface which result in the discreteness of surface roughness2. It is found that the degree of surface glossiness depends on that of roughness. The surface glossiness increases with the decrease of surface roughness. Only when the surface roughness decreases to a certain degree, the surface glossiness increases sharply; while the glossiness increases very little when the roughness is much lower.3. The degree of glossiness of stones is also related with material inherent flaws and the remained craters on stone surface. After tracing the changes of surface morphologies of stones, it is found that some of these craters on stone surface are inherent, and others formed in the former coarse grinding are inherited from some craters that can not be removed by polishing.4. On the basis of considering the influences on surface glossiness of material inherent limitations and the remained craters, a new conception------"zero-limitation glossiness" isproposed in this thesis, which provides a reference for evaluating quantitatively the influences on surface glossiness of machining deficiencies and for forecasting the highest glossiness in practical stone machining.