The title ZnO-P_(2)O_(5)-H_(2)O reaction system based zinc phosphate antirust pigment is characterized by use of X-ray,FT-IR,TEM and chemical analysis in terms of its constitution,crystal water,particle size distribution,morphology of particle,solubility,wetting angle,specific surface area and its dispersibility in alkyd resin,and its physical and chemical properties.
The addition of SiO_2 can suppress the grain growth of TiO_2 crystal,increase the hydroxyl content of TiO_2 film,decrease the contact angle for water of TiO_2 films and enhance the hydrophilic property of TiO_2 films.
By means of wetting balance method and spreadability method, the wetting time , wetting force and the wetting angles of Sn3.0Ag0.5Cu lead-free solder were tested under the conditions of different temperatures and coatings on substrates.
It was showed that the liquidus and solidus temperatures of the alloy are 491.0℃ and 445.0℃,respectively,the wetting angles of the alloy on Ni plate are less than 15°under temperature≤ 550℃,and the spreading area on Ni plate is increased with increasing in temperature from 490℃ to 550℃.
To select the suitable surfactant,wetting Gibbs free energy change ΔG were calculated by the measurement for surface tensionγg-L and wetting anglesθ of Zinc phosphate with different surfactants. According to the measured values for surface tension of zinc acetate solution having non-ionic surfactant and the corresponding adsorption of OP-10 on Zinc Phosphate,the action mechanism of OP-10 in preparation of microcrystalline Zinc Phosphate was inferred.
Alloying with Bi、Ni, SZC solder can improve the wettabilityand the wetting angles decrease half from that of Sn-9Zn by using RMA flux, when Ni content increase, The additives have little effect on the composition of interfacial IMC and the reaction layer decrease from 4um to 3um in SZC-Bi-Ni alloy for the formation of (Cu, Ni)-Zn compound, which resulted less Zn atoms diffusing to the interface.