54results about How to "Good physical and chemical compatibility" patented technology

The invention provides a method for preparing carbon / carbon composite material nanometer silicon carbide-mullite composite external coating. The method comprises the following steps: adding mullite powder and nanometer silicon carbide powder into isopropanol for ultrasonic oscillation, adding iodine into the mixture for another ultrasonic oscillation, and placing the mixture in a hydrothermal reaction kettle; clamping the carbon / carbon composite material test sample with SiC internal coating on a cathode clip in the hydrothermal kettle for hydrothermal electrophoresis reaction, taking out anddrying the test sample to obtain the carbon / carbon composite material nanometer silicon carbide-mullite composite external coating. The mullite adopted as the C / C-SiC external coating has higher thermal stability and oxidation resistance, and has melting point more than 1,800 DEG C. The coefficient of thermal expansion of the mullite is close to that of the SiC, so the mullite cannot generate thermal stress at high temperature. The mullite can generate SiO2 and Al2O3 with low penetration and excellent high-temperature stability with oxygen at high temperature, additionally; nanometer silicon carbide particles can effectively overcome microcrack and other defects of the SiC internal coating, so that the high-temperature oxidation resistance of the coating can be greatly improved.

The invention relates to anti-oxidation coating and a preparation method thereof.The anti-oxidation coating comprises an adhering layer and a ceramic layer which are sequentially prepared on a base, wherein the adhering layer is made of W, the ceramic layer is made of Yb2SiO4, the adhering layer is 0.05-0.15mm in thickness, and the ceramic layer is 0.15-0.3mm in thickness.The preparation method includes the steps of firstly, preheating the base, and controlling the temperature of the base to be 100-200 DEG C; secondly, using a plasma spraying method to sequentially prepare the adhering layer and the ceramic layer on the preheated base.The anti-oxidation coating and the preparation method thereof have the advantages that the coating is prepared by the single plasma spraying process; the preparation method is simple in process, low in cost and high in efficiency; the technical difficulties that traditional coating preparation technologies of carbon-fiber-reinforced ceramic-based composite materials are complex and the prepared coating is weak in steam corrosion resistance.

The present invention relates to one kind of gradient Fe / Al2O3 material coating on steel substrate part and its preparation process. The coating consists of one inner layer, one middle layer and one outer layer, and has Al2O3 content gradually raised from 10-20 wt% in the inner layer to 100 wt% in the outer layer, Fe content gradually lowered from 65-85 wt% in the inner layer to 0 wt% in the outer layer, and Al content gradually lowered from 5-15 wt% in the inner layer to 0 wt% in the outer layer. The coating is prepared through spraying process to form the inner layer and the middle layer, and sol-gel process to form the outer layer with painted Al(OH)3 sol. The coating is wear resistant, corrosion resistant, high in high temperature oxidation resistance and high in high temperature heat stability, may be well matched physically and chemically with steel base in less macrostress and moderated interface combining strength.