All of the artifacts of household appliances have a high demand for corrosion, and the more common solution is to use a chemical and electrochemical reaction to form a phosphate chemical conversion film in a metal coating pretreatment process (this process Referred to as phosphating, the formation of phosphate conversion film known as the phosphate film), it and after the road coating with the protection of household appliances and other metal products to ensure that 10 years or more time does not occur rust and other issues.
Although the corrosion resistance of phosphating and other properties is very good, but it also has a lot of problems, such as high energy consumption, more serious pollution, containing heavy metals, wastewater treatment more difficult, easy in the pipe wall and pipe slag and a series of problems The With the continuous progress of science and technology and environmental protection requirements continue to improve, more environmentally friendly metal surface treatment process is being developed around the world, the current research work focused on environmental protection phosphating and alloy catalyst for the new process of two aspects.
Phosphating process development process
Phosphating treatment process, the earliest reliable record is the British CharlesRoss in 1869 to obtain the patent, has been more than a century. Phosphorus treatment process can be divided into the following stages:
Before the First World War, the basic stage of the phosphating process, this period completed many basic discoveries, mainly in the UK.
Between the First World War II, a large-scale industrial application phase, the development center of the phosphating process was transferred from the United Kingdom to the United States. During this period, the United States T.W.Coslet zinc, zinc oxide or zinc phosphate dissolved in phosphoric acid to make the first zinc-based phosphating solution. The results of this research have greatly promoted the development of phosphating process. Parker rust research company developed ParcoPower (Parker powder) preparation of phosphating solution, the phosphating treatment time is shortened to 1 hour, 1929 Bonderizing again phosphating time reduced to 10 minutes, 1934 phosphating technology has made revolutionary The use of the phosphating solution is sprayed onto the workpiece.
During the Second World War, the new stage of the phosphating process took place mainly in Germany.
After the end of World War II, the steady development and improvement of phosphating process stage, phosphating process rarely breakthrough. During this period, the important improvement of phosphating treatment technology is: low temperature phosphating, a variety of methods to control the phosphating film weight, continuous high-speed phosphate strip (treatment time only 5 seconds).
90s of last century, foreign environmental protection coating pre-treatment process has gradually become a hot topic in the industry. As the phosphating treatment process is more toxic, the pollution is more serious mainly nitrite, heavy metal Ni2 +, Cr6 +, Mn2 + plasma. Therefore, the field of research is mainly focused on the search for alternatives to these substances, mainly divided into no nitrite phosphating and no nickel phosphating. However, Hefei City Metal Surface Engineering Technology Research Center Director Liu Wanqing said that this environmentally friendly non-toxic phosphating process is only in the original phosphating system in the "circle", although the phosphating process to reduce the toxic and hazardous substances, but not from Fundamentally solve the problem. Shanghai Kemetel Chemical Co., Ltd. (Chemetall) the responsible person also said that the metal surface pretreatment process development direction should not only reduce the toxic and hazardous substances, but should fundamentally solve the problem of phosphate pollution.
Development of Alternative Technology for Alloy Catalyst
Beijing Branch of Science and Technology Development Center in August 2005 launched alloy catalytic liquid instead of traditional electroplating. The Center, with reference to the advanced technology of surface treatment of foreign materials, combined with China's raw materials market, with the assistance of relevant departments such as the Chinese Academy of Sciences, the Ministry of Chemical Industry, the Ministry of Metallurgical Industry and the Ministry of Science and Technology, after several years of painstaking research, Electroplating for metal surface treatment of the best project - a new generation of environmentally friendly special surface alloy catalyst. Its advent of China's metal surface protection industry to a new milestone, creating a new era of metal surface protection industry, experts in the demonstration, the Chinese Academy of Sciences, Ministry of Metallurgical Industry and other units and experts have given a very high Evaluation. "People's Daily", "Economic Daily", "Science and Technology Daily", "Workers Daily" and other newspapers have made reports, CCTV's science and technology section has done a lot of special interviews. The product has passed the national anti-corrosion performance appraisal and the Chinese Academy of Preventive Medicine sanitation sanitation test, and has been to the State Intellectual Property Office to declare invention patents.
A new generation of environmentally friendly special surface alloy catalyst Features:
1, non-toxic and tasteless, no waste discharge, the human body does not constitute harm, the environment does not cause pollution, the country strongly promote the promotion of green products.
2, the process is simple, easy to use, no external power supply, can be placed directly in the catalyst solution soak 20 to 40 minutes, you can form a bright mirror, such as the surface of the mirror, with the effect of stone, magically The iron into a stainless steel, both beautiful and durable. Whether it is the production of catalytic liquid, or the workpiece processing, production operations are very convenient, all use domestic Tesco raw materials, very suitable for enterprise single or mass production.
3, the cost is low, the cost per square meter of about 10-15 yuan (according to plating requirements, the surface of the catalytic thickness of different costs floating, such as pure decorative surface, the cost per square meter is only 3-6 yuan), only Chrome plated 1/3, stainless steel 1/4.
4, with the metal base with high strength, generally in the 350 ~ 400Mpa, can not afford to skin, do not fall off, never rust, both to maintain the original mechanical properties of metal parts, but also increased wear resistance, corrosion resistance.
5, the surface alloy layer is uniform and dense, whether it is counterbore, deep hole, pipe wall, product corner and other complex shape of the surface, can be surface treatment, no pitting, no pores.
6, corrosion resistance, the product is treated after the surface is an amorphous coating, because no grain boundary, so particularly good corrosion resistance (see Table 1). While the surface hardness is high, after heat treatment, the surface of the coating to form an amorphous and crystalline mixture, the hardness of up to 1200HV (see Table II, Table III).
7, after the catalytic treatment of the surface is an amorphous state, that is, in the basic plane state, lubricity, so the friction coefficient is small, non-adhesive good.
8, good imitation. Technology without the tip of the current density is too large phenomenon, in the sharp or edge protruding part of the thickening is not excessive, no grinding after processing.
9, the thickness of control. Can be used to repair parts and molds due to grinding or wear caused by the size of the tolerance, so that scrap parts reuse.
10, coating other indicators Performance:
Microstructure: amorphous alloy, non-magnetic
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