In the field of metal surface treatment, the phosphating process serves as a core technology for protection and coating, and its performance enhancement has always relied on breakthroughs in materials science. Zhaoqing Xinrunfeng Advanced Materials Co., Ltd. (hereinafter referred to as "Xinrunfeng"), focusing on zinc-based material innovation, has launched ultra-0# zinc ingot environmental-grade sub-nanoscale 99.7% indirect-process zinc oxide. With its molecular-level precise regulation and green manufacturing characteristics, this product is reshaping the technical coordinate system of the phosphating bath industry. As a leader in zinc-based material innovation and carbon neutrality solutions, Xinrunfeng has pushed the application of high-purity zinc oxide to new heights through its "Zinc Technology 4.0" strategy.
The core competitiveness of Xinrunfeng's 99.7% high-purity zinc oxide stems from its molecular-level precise control over the entire phosphating reaction process:
Zinc oxide crystals with a hexagonal wurtzite structure react with phosphoric acid in the phosphating bath in accordance with the Arrhenius kinetic model, with the activation energy precisely controlled at 45 kJ/mol. Through sub-nanoscale particle size design (D50 = 0.8-1.2 μm), its dissolution rate is 2-3 times higher than that of traditional zinc oxide. Even in a low-temperature environment (35°C), it can still achieve a zinc ion release rate of over 65% within 30 seconds. This "on-demand release" feature increases the nucleation density of the phosphating film by 300% and controls the porosity below 3%, forming a dense and uniform protective barrier.
As an amphoteric oxide, zinc oxide dynamically adjusts the solution pH value through the Henderson-Hasselbalch equation, with each 1% addition stabilizing the pH value by 0.15 ± 0.03. This property effectively inhibits the excessive precipitation of Fe3?, prevents passivation of the metal surface, and ensures the phosphating reaction proceeds under optimal acidity and alkalinity. Data from an automotive component production line shows that after adopting Xinrunfeng's zinc oxide, the pH fluctuation of the phosphating bath is controlled within ±0.2, and the salt spray resistance time of the film layer has increased from 240 hours to over 500 hours.
The lattice matching degree between zinc oxide and zinc phosphate crystals reaches 92% (Δa/a = 0.93%, Δc/c = 1.17%), acting like a "molecular-level construction template" to guide the oriented growth of zinc phosphate crystals along the (020) crystal plane. XRD analysis shows that the orientation degree of the (020) crystal plane of the phosphating film is increased by 27%, forming a regular flake structure. This enables the film layer to achieve a microhardness of 450-600 HV and a friction coefficient reduced to 0.08-0.12, significantly improving corrosion resistance and wear resistance.
Xinrunfeng has established an industry-leading impurity control system to ensure the purity of every zinc oxide crystal:
Dual detection methods—XRD semi-quantitative analysis (detection limit: 0.1%) and magnetic separation (detection limit: 0.05%)—are adopted to eliminate unoxidized elemental zinc during production. Experimental data shows that when the elemental zinc content exceeds 0.1%, the defect rate of the phosphating film soars from 5% to 12%, and the salt spray life decreases by 25%. However, Xinrunfeng's products control the elemental zinc content below 0.03%, ensuring the film porosity ≤ 5% and a 100% pass rate in salt spray tests.
Through high-precision ICP-OES detection, the content of heavy metal impurities such as lead (Pb < 5 ppm) and cadmium (Cd < 0.01%) is far below the requirements of the RoHS directive; the chloride ion residue is ≤ 0.01%, completely avoiding the penetrating corrosion of Cl? on the phosphating film. In the application of a certain aviation magnesium alloy component, the composite CaO/ZnO system has increased the salt spray resistance time to 360 hours, breaking the limit of traditional processes.
With the goal of building a "zero-carbon zinc-based material ecosystem," Xinrunfeng integrates green concepts into the entire production process:
With the help of titanium salt activation technology, sub-nanoscale zinc oxide (500 nm) can shorten the phosphating film formation time to less than 40 seconds in a low-temperature environment (35°C). Compared with the traditional high-temperature process (85°C), this reduces energy consumption by 60% and the wastewater COD value by 65%. Data from an environmental protection phosphating production line shows that it saves 30% of energy annually and reduces wastewater discharge by 5,000 tons, achieving a win-win situation for economic and environmental benefits.
The original membrane electrolysis wastewater treatment process is developed, with a zinc recovery rate ≥ 95%, realizing a material closed loop of "production - use - recycling." Combined with the digital transformation of the two major production bases in Gaoyao and Huaiji, the unit energy consumption is optimized by 30%, reducing carbon emissions by 15,000 tons annually and advancing the layout of the full-industry-chain carbon neutrality goal by 2030.
Xinrunfeng's zinc oxide has formed precise solutions covering multiple industries:
To meet the high flatness requirements of automotive sheets, 99.9% ultra-high-purity zinc oxide is combined with a zinc nitrate/zinc phosphate ratio (35%: 45%), controlling the film thickness tolerance within ±0.5 μm, achieving a coating adhesion of Grade 0, and a stamping forming rate of over 99%. It has become a designated material for many mainstream automobile manufacturers.
Through Al3? doping (0.5-1.2%) and Ca2? synergy (Ca/Zn = 0.3-0.5), a Zn?Ca(PO?)?·4H?O composite film layer is constructed, with the microhardness increased to 550 HV. It has been successfully applied to high-load components such as automotive gears, reducing wear by 30% and extending the maintenance cycle by 2 times.
Targeting the active characteristics of magnesium alloys, a CaO/ZnO composite system (Ca/Zn = 0.3-0.5) is developed. Through EDAX surface distribution correction technology, the segregation of Mg?(PO?)? is avoided, achieving a breakthrough of 360 hours of salt spray resistance in the field of aviation components.
Xinrunfeng has built a "detection - production - application" trinity digital quality system: X-R control charts are used for raw material warehousing to monitor particle size fluctuations (UCL = 1.25 μm, LCL = 0.85 μm); online sensors are used in the production process to real-time calibrate the zinc/phosphorus molar ratio (1.05 ± 0.05); before delivery, finished products undergo salt spray tests (NSS > 240 hours) and XRD crystallinity detection. Relying on Minitab data analysis, the correlation coefficient (R2) between zinc oxide purity and phosphating film performance is ensured to be > 0.95, realizing full-dimensional quality control from micron-level particles to atomic-level structures.
Driven by the dual goals of "double carbon" (carbon peaking and carbon neutrality) and manufacturing industry upgrading, Xinrunfeng uses zinc-based materials as a "brush" to draw a technical blueprint of precision and greenness in the field of metal surface treatment. From the precision protection of automobile manufacturing to the extreme environment application of aerospace, its 99.7% high-purity zinc oxide is not only a material product but also a key to opening the 4.0 era of phosphating technology. In the future, Xinrunfeng will continue to take "reshaping the future of zinc-based materials with technology" as its mission, promote the in-depth application of zinc-based materials in new energy, high-end manufacturing and other fields, and lead the industry towards a new realm of molecular-level precision and full-life-cycle low carbon.
