[Copper, aluminum and zinc parts rust prevention, why is it so difficult?]
In the fields of machining, hardware manufacturing, electronic appliances and even building decoration, copper, aluminum, zinc and their alloys are used everywhere. Copper has excellent electrical and thermal conductivity, aluminum is lightweight and corrosion-resistant, and zinc's sacrificial anode protection is a classic solution for steel rust prevention. However, these non-ferrous metals themselves often face the embarrassment of "rust prevention". Once the zinc layer is damaged, the matrix is prone to frost; the surface of aluminum parts will oxidize rapidly in humid environments, generating loose white powder; copper parts will darken and green, affecting the appearance and conductivity.
Traditional anti-rust methods, such as applying anti-rust oil, passivation treatment, electroplating protection, etc., have more or less defects: anti-rust oil is sticky and difficult to clean, affecting subsequent assembly; hexavalent chromium passivation is highly toxic and limited in environmental protection; once the electroplating layer is damaged, it accelerates local corrosion. When downstream customers have higher and higher requirements for the surface cleanliness, oil-free and environmental compliance of the workpiece, enterprises urgently need a more advanced and safer anti-rust solution.
[Hank BS-400 Series: Professional Answers to Nonferrous Metal Rust Prevention]
In response to the above pain points, the Hank BS-400 series of anti-rust products came into being. It is not a single bottle of agent, but a set of systematic solutions covering a variety of non-ferrous metals and a variety of process scenarios. The series is based on water-based anti-rust technology. Through the combination of special film-forming agents and corrosion inhibitors, a uniform, transparent and thickness-controllable adsorption film can be formed on the surface of copper, aluminum, zinc and alloys. This film is like putting an "invisible raincoat" on metal, which can effectively block the erosion of oxygen, water molecules, chloride ions and acid and alkali media.
Unlike ordinary anti-rust oils, the Hank BS-400 series does not stick to hands or hang after drying, and the workpiece can be made into a "dry hand film", which can be assembled or packaged directly without additional cleaning. More importantly, this protective film has a selective affinity for non-ferrous metals - it will not destroy the conductivity of copper, the weldability of aluminum, and the adhesion of zinc coating. Instead, it can improve the anti-fingerprint and anti-scratch ability of the workpiece surface.
[Customized protection for different metals]
The Hank BS-400 series is not "one bottle goes all over the world", but has developed multiple models based on metal characteristics to achieve precise protection.
For copper and copper alloys (such as brass, red copper, beryllium copper), Hank BS-401 uses high-efficiency copper corrosion inhibitors (such as new azole derivatives), which can form a dense coordination complex film on the copper surface. This film can effectively prevent the "black" reaction of sulfides and the "patina" formation of chlorides. It is especially suitable for high-conductivity and high-finish workpieces such as terminals, connectors, heat sinks, and precision copper nuts. After being treated by BS-401, the corrosion resistance time of copper parts in salt spray tests can be greatly improved, and the contact resistance is almost unchanged, meeting the strict standards of the electronics industry.
For aluminum and aluminum alloys (such as 6063, 5052, 7075, etc.), Hank BS-402 uses environmentally friendly organosilanes and nano-corrosion inhibitors to cooperate. The surface of aluminum parts is prone to an oxide film. This natural oxide film is uneven and porous. BS-402 can penetrate into the micropores and bond with them to form a hydrophobic three-dimensional network structure. The film has strong bonding force with the aluminum matrix and excellent weather resistance, which can effectively prevent "white rust" and "filamentous corrosion". What's more rare is that BS-402 does not contain toxic hexavalent chromium, fully complies with RoHS and REACH regulations, and the rinsing water is biodegradable, allowing enterprises to enjoy environmental protection dividends.
For galvanized parts and zinc alloy die-castings (such as zinc alloy handles, locks, and auto parts), Hank BS-403 adopts a "bipolar corrosion inhibition" mechanism, which not only protects the zinc layer, but also prevents galvanic corrosion of the underlying steel. Zinc is an amphoteric metal and is prone to corrosion in both acidic and alkaline environments. BS-403 effectively inhibits the precipitation of "white frost" by adjusting the pH value of the surface micro-area and forming a protective film containing zinc salt complexes, while giving the workpiece good hydrophobicity and resistance to hand sweat corrosion. After the galvanized parts are treated with BS-403, the surface remains matte or bright, and the adhesion of subsequent painting and powder spraying does not decrease but rises, which greatly reduces the problem of paint film peeling caused by poor pretreatment.
[The process adaptation is simple, and the cost reduction and efficiency increase are significant]
Another major advantage of the Hank BS-400 series is that the process adaptability is extremely strong. Whether it is soaking, spraying or brushing, uniform coverage can be achieved. Take the most common soaking process as an example: after the workpiece is degreased and rust removed, it is directly immersed in the BS-400 diluent (the concentration is usually used at 1:10~ 1:20 with deionized water), soaked at room temperature for 1 to 3 minutes, and then naturally dried or dried after taking it out. This series of products is non-flammable and non-explosive, with extremely low volatile organic compound content, almost odorless, safe operation, and no special protection is required.
From a cost perspective, the use of Hank BS-400 series can save about 20% to 30% of the overall cost compared to traditional anti-rust oils. Because oily anti-rust requires a subsequent degreasing cleaning process, a large amount of cleaning agent and labor is consumed; while the water-based anti-rust film is thin and uniform, the treatment area per kilogram of concentrated liquid is large, and the waste liquid treatment cost is low. In addition, due to the dry surface of the workpiece, there is no need for isolation paper when packaging, and the storage environment requirements are correspondingly reduced, and the yield rate and customer satisfaction are both improved.
An auto parts company has done a comparative test: half of the same batch of copper-aluminum composite heat sinks are treated with anti-rust oil, and half are treated with Hank BS-402. After three months of storage, the surface of the oil anti-rust parts adheres to dust, and ultrasonic cleaning is required before assembly, and local oil spots are uneven; the surface of the BS-402 parts is as clean as new, without any oxide generation, and directly enters the brazing process, and the yield is increased by 4.8%. Another zinc alloy lock factory uses BS-403 for anti-rust of die-casting parts and exports it to South East Asia by sea. After going through high temperature and high salt spray environment, the product has no white rust and no corrosion when unpacking inspection, and the customer successfully signs for it, thus establishing a long-term order.
[Precautions for using Hank BS-400 series]
Although the performance of this series of products is superior, scientific use can maximize the effectiveness. First, the pretreatment of the workpiece is crucial. If there is residual oil stain, oxide skin, metal chips or alkaline cleaning agent residue on the surface, it will hinder the effective combination of the anti-rust film and the substrate. It is recommended to use the complete pretreatment process of degreasing-washing-pickling activation-washing. Secondly, the dilution concentration should be adjusted strictly according to the product manual. If the concentration is too high, it will cause waste and the film layer is too thick, which may change the size of the workpiece; if the concentration is too low, the protection will be insufficient. Thirdly, the drying method is recommended to use hot air circulation drying at 60 to 80 degrees Celsius, which can accelerate the curing of the film layer and improve the initial water resistance. If natural drying is used, it is necessary to keep the relative humidity of the environment below 60% to Finally, workpieces that have been handled by the Hank BS-400 should be handled and packaged with cleaning gloves to avoid touching them with bare hands, leaving sweat and salt, and damaging the local protective film.
In addition, different models cannot be mixed at will, especially the BS-401 for copper parts cannot be used for aluminum parts, because the copper corrosion inhibition component in it may induce potential corrosion of aluminum. Similarly, the BS-403 for zinc parts contains special regulators and cannot be used for pure copper decorative parts to prevent discoloration. Hank's technical support team can provide customized selection suggestions according to customer material, processing state, rust prevention cycle, follow-up process (such as welding, painting, conductive requirements), and can also assist in establishing rust prevention inspection specifications on site when necessary to help customers realize the transition from "passive fire fighting" to "active prevention".
Environmental protection and future trends
In the era of peak carbon dioxide emissions and carbon neutrality, green surface treatment technology has become the development trend of the industry. Hank BS-400 series uses water as the dispersion medium, does not contain heavy metals, phosphates, and nitrites, and the waste liquid can be degraded through the conventional sewage system without special treatment. Its biodegradability is higher than 90%, and its ecotoxicity is extremely low. After being tested by an authoritative third-party testing agency, it has no acute toxic effect on fish, fleas, and algae. This not only reduces the pressure on environmental protection of enterprises, but also meets the audit requirements of international customers for green manufacturing in the supply chain.
With the booming development of 5G communication, new energy vehicles, smart homes and other industries, the use of copper, aluminum, zinc and their alloys continues to rise, and the demand for anti-rust has also expanded from a single "shelf life anti-rust" to "functional anti-rust". For example, 5G base station filters require aluminum alloy surface anti-rust while ensuring electromagnetic shielding performance; new energy vehicle battery connectors require copper bar anti-rust and low contact resistance; smart door lock zinc alloy shells hope to be sprayed with antibacterial paint directly after anti-rust treatment. The Hank BS-400 series is incorporating these requirements into product design through continuous formula iteration. In the future, the series will also introduce innovative products such as visual anti-rust film (color rendering under UV lamps) and self-healing anti-rust film, making the anti-rust process more intelligent and controllable.
[Conclusion]
"What should I do to prevent rust in copper, aluminum and zinc parts?" This problem that plagues many engineers and purchasers is no longer unsolvable in the face of the Hank BS-400 series. It uses professional technology precipitation, differentiated product architecture, and green and environmentally friendly chemical concepts to deliver an answer that balances performance and responsibility. Whether you are worried about the blackening of copper terminals affecting conductivity, or you are anxious about the white rust of aluminum shells being complained by customers, or you are distressed that zinc die castings have spots in a humid warehouse, you might as well give the Hank BS-400 series a try. When you see that the non-ferrous metal workpiece that was originally a headache is still as smooth and stable as ever after being stored for several months, you will understand that rust prevention is not a hassle, but the calmness of choosing the right solution. Choosing the Hank BS-400 series allows non-ferrous metal workpieces to "stay young forever" and allows production and delivery to move forward without worry.
