Study On The Properties Of Yellow Loam Coating For Iron Casting

With the development of modern industry, improving the quality of casting by coating on the mold surface has been well used. Recently, casting production has gradually dominated world, increasing demand for sand brings new challenges to the environment. The yellow loam natural clay sand exploited by Donghua University is a new technology which is green and environmental protection. Good results can be achieved when casting from thin walled pieces to middle and thick walled pieces castings. It can be due to the formation of thin sintering skin on the casting surface in the pouring process. This thin sinter skin is attached to casting surface at high temperature, and it can be easily stripped when cooling. Hence, it is possible for the iron castings to be knocked out at high temperature, and the production efficiency has been raised. In addition, there is no coal-dust in the sand, hence the technology is low cost and without any pollution, meeting the requirements of "green cast".To broaden the field of yellow loam which is used in the foundry and popularize the energy saving, environmental protection, high quality, efficient modeling material, a sintered and stripped coating for iron casting is investigated, and the technological properties of the coating are mainly measured. In the coating, yellow loam powder and slag powder are used for refractory powder. Research achievements gained in this work are listed as follows:1. The favorable preparation of yellow loam coating is gained by the analysis of particle characteristics.2. Particle sizes distribution and particle morphology which is altered by the method of abrasive of yellow loam powder and slag powder are gain by laser particle size distribution measurement and scanning electron microscopy; technology of the abrasive is gained. 3. Performance characteristics of compositions are gained by adding different coating compositions, so the compositions of coating are defined further.4. Yellow loam coating is improved by some methods, components of improved yellow loam coating are analyzed and the performances of yellow loam coating are improved.5. The pouring experiments are carried out to verify the coating. The results have indicated that crack-resistance and painting are excellent, and much smoother surface of the coatings can be obtained.