AlSi-Polymer powder

       Main components of aluminum-silicon polyphenylester powder: the powder is mixed with aluminum-silicon powder and polyphenylester powder. The ratio of aluminum-silicon powder and polyphenylester powder can be adjusted according to needs. 50%, polyphenylester is used as a soft phase in the coating, and the hardness and bonding strength of the coating will decrease as the proportion increases. A commonly used ratio is 40%.



The silicon content in the aluminum-silicon powder is generally about 12%, and the powder is made by gas atomization.



Polyphenylester powder is an organic substance, also known as polyphenylparaben or aromatic polyester. Polyphenylene ester can be used for a long time at 315 °C, and the short-term use temperature can be as high as 370 ~ 425 °C. It is said that it has the best comprehensive properties of thermal stability, heat capacity, self-lubrication, hardness, electrical insulation and wear resistance among all known polymer materials. At the same time, it has excellent dielectric strength and little dielectric loss, and is insoluble in any organic solvent and general acid.



Commonly used powder particle size: -125 +11 μm.



Production method: mechanical mixing or mechanical cladding.

Powder morphology: irregular shape, mixed powder morphology shown in Figure 1, mechanical coating powder morphology shown in Figure 2.

Fig.1 Morphology of mixed powder

Fig. 2 Morphology of mechanical coating powder



Main use: Due to the good thermal stability and self-lubricating properties of polyphenylene ester, it can be used as an abradable sealant coating in gap control applications when mixed with aluminum and silicon. As a wearable sealing coating, alumino-silicon polyphenyl ester is widely used in aero-engine compressor components. Thousands of engine components have been sprayed with this material, and the coating thickness can reach 8mm (see Figure 3), and the service time is 5000 hours. above.

Figure 3 Plasma sprayed Al-Si-polyphenylene coating



Spraying method: Plasma spraying is usually used.



Coating performance: Usually, nickel-aluminum bottom layer is sprayed, and aluminum-silicon polyphenyl ester is used as the surface layer. The bonding strength of the coating can reach 8-10MPa; the hardness of the coating is 605-80HRY15, and the maximum service temperature is 320℃. The coating structure is shown in Figure 4 and Figure 5. The coating structure is uniform, mainly composed of aluminum-based metal skeleton in the white part and polyphenylester in the black part.

Figure 4 Metallographic structure of aluminum silicon polyphenyl ester coating - 200 times

Figure 5 Metallographic structure of aluminum silicon polyphenyl ester coating - 500 times