Preparation Of Composite Ceramic Incombustible Coating For Aluminum Alloy Surface

Considering the organic dope is mostly used for the inner decoration in metro systems, whereas Heavy smoke with high temperature will easily be accumulated to cause the severe personnel casualty and the economic loss, thus the requirement for fire protection in metro systems is continuously increasing. Therefore, according to the international standard of the fire protection for the railway train——British fireproofing standard, in the paper the experimental research and finite element simulation under high temperature were carried out. The specific content and results are as follows:In this paper, the preparation of incombustible ceramic coat on Al Alloy plane for interior decoration of metro systems is made up of inorganic binding agent and paintings. The synthetic method and the influence of Al/P mole ratio on inorganic binding agent have been studied; The relationship of coating density and the amount of the binding agent, inorganic flame retardant, addition agent and paint grainsize have been investigated; the microstructure and phases on the coating have been analyzed. The performance tests have been carried out for the prepared ceramic coat, concentrated on the fire-proof according to the British standard.The experiment results show that when the adhesive dosage was in range of 60%~65% and the granularity of additives was1~2μm, the surface of coatings was homogeneous, compact and no shrinkage holes. The analysis for the microstrucre and phases indicates that some new phase were found between the interface of the coating and metal matrix. The transitional layer formed by mutual diffusion on the interface and mechanical interlinkage combine coating with metal material firmly. The tests of thermal-quake resistance and erode resistance indicated that the coatings can make thermal-quake resistance keep adhesive for 35 times, acid resistant for 14 hours, alkali resistant for 24 hours and salt resistant for 42 days. According to the incombustible materials standard of GB12441–1995 and britain BS476–4, the detecting was carried out for the physical and chemical properties of coatings, which showed that the prepared ceramic coating achieved the detecting and facing standard of nation and britain incombustible level for the fire retardant coating. The fireproof duration of coatings could last for 30 min that was uninflammable and did not fall off , smokeless and no irritant gas. The coating shows certain function of fire retardant. The variation on high temperature under the condition of the fire for the coating has been simulated through the finite element numeral simulation, and the relationship of temperature field and stress status between the coat stuff and metal matrix have been obtained. The research results in the paper provide theoretical evidence for the preparation of incombustible ceramic coating with the high level, also can be generalize and applied to fire protection in metro systems.