Aluminum die castings surface treatment methods
1, aluminum phosphide
Meticulous way of using SEM, XRD, and potential one-time curves, changes of membrane re-discuss the accelerator, fluoride, of Mn2 +, of Ni2 + and Zn2 +, PO4; and Fe2 + and other aluminum phosphide process. Seminars marked: Guanidine nitrate has good water solubility, low dosage, rapid film-forming characteristics of aluminum phosphide effective accelerator: fluoride can promote the film, to increase the coating weight, and grain refinement; Mn2 +, Ni2 + significantly grain refinement, the phosphate film average, compact and can improve the appearance of the phosphate film; Zn2 + concentration is low, you can not film or film with the Zn2 + concentration, membrane weight gain O4 content of the phosphate coating weight affect progress PO4. The content of the phosphate film weight increased.
2, alkaline aluminum electrolytic polishing process
Stopped the seminar of the alkaline slurry solution system, unmatched corrosion inhibitors, viscosity agents on the polishing effect, the victory achieved polishing the alkaline solution system with good results, and the first time can reduce the operating temperature and extend the solution to use life while improving the polishing effect of the additives. The experimental results indicate that: to participate in appropriate additive in NaOH solution can produce good polishing effect. The inquiry was also found that: the NaOH solution with glucose under certain conditions, to stop the DC constant voltage electrolytic polishing, aluminum exterior reflectivity can reach 90%, but the experiment there are still unstable elements, pending further discussion. Explore the feasibility of using DC pulse electropolishing polished aluminum under alkaline conditions, the results indicate: the leveling effect of pulse electropolishing to reach the DC constant voltage electrolytic polishing, but its leveling slower. 316 stainless steel tube
3, aluminum and aluminum alloy environmentally friendly chemical polishing
Certainly the development of environmentally friendly chemical polishing of new technology-based solution to a sulfuric acid phosphate, the technology to complete the zero emissions of NOx and restraint in the past similar technical quality defects. The new technology, the key is to add some compounds instead of nitric acid has a special role in the base fluid. Firstly, demand for aluminum in acid chemical polishing process to stop profiling, in particular, should focus on to discuss the role of nitric acid. The main role of the nitric acid in aluminum chemical polishing is to suppress pitting corrosion, progressive polishing brightness. Separation in pure phosphoric acid, sulfuric acid in the chemical polishing experiment that special substances should be added in a sulfuric acid phosphate can suppress the pitting corrosion mitigation to general corrosion, and must have a good leveling and light effects
4 Electrochemical appearance of aluminum and its alloys to strengthen disposal
Anodizing of aluminum and its alloys in a neutral system stacked to constitute a class of ceramic amorphous composite conversion coating process, performance, morphology, composition and construction of a preliminary discussion of the film formation process and mechanism of the film. Process discuss the results indicate that, in Na_2WO_4 neutral hybrid system control film to promote a concentration of 2.5 to 3.0 g / l, network synthesis release agent concentration of 1.5 ~~ 3.0g / l, Na_2WO_4 concentration of 0.5 ~ 0.8g / l The peak current density of 6 12A/dm ~ 2, the weak mixing to achieve intact average, good gloss gray series of inorganic non-metallic film. The film thickness of 5 to 10μm, the microhardness of 300 ~ 540HV, excellent corrosion resistance. Better compliance, anti-rust aluminum, wrought aluminum and other series aluminum alloy can be used to film the neutral system of aluminum alloy.
5 YL112 aluminum alloy exterior disposal technology
YL112 aluminum alloy commonly used in the construction of parts of cars, motorcycles. The information prior to the application needs to stop the appearance of disposal, in order to progress in its anti-corrosion, and constitutes the outer surface layer easily with the organic coating separation, in order to facilitate the subsequent appearance.