Development and application of the hottest infiltr

Development and application of infiltration technology

I. Introduction

infiltration technology is to use the infiltration agent to penetrate the porous workpiece under the pressure to fill the gap through curing reaction. Infiltration technology is a new technology developed by modern science and technology

infiltration technology is widely used in casting defect sealing, wood pest prevention, corrosion prevention, flame retardant, powder metallurgy parts reinforcement, corrosion prevention and sealing, cement products anti alkali or acid corrosion, electrical and electronic components moisture-proof and insulation

the application of modern industrial infiltration technology can be traced back to the casting plugging process in the 1930s, when water glass was recycled to fill the gap of castings. 5、 In the 1960s, with the development of the automotive industry, the United States, the former West Germany, the former Soviet Union and other industrial developed countries promoted the development and application of the first generation of infiltrating agent sodium silicate type infiltrating agent for the sealing of pressure castings, and developed from local or atmospheric pressure infiltration process to vacuum pressure infiltration process

since the 1970s, the emergence of energy crisis has promoted the development of light vehicles. Many cast iron parts have been replaced by light metals such as aluminum, magnesium, zinc and their alloys, reducing vehicle weight, reducing energy consumption and improving vehicle performance. However, light metal castings are prone to produce micropores, resulting in leakage of pressure castings. At the same time, powder metallurgy sintered parts are widely used, further saving materials and machining costs. The problem of porous material leakage needs to be solved urgently, which promotes the demand for infiltration technology. At the same time, the development of chemical industry has also promoted the research and development of infiltrators (4) good fire performance, a wide variety of uses, excellent performance infiltrators continue to appear, and polyester type second-generation infiltrators and anaerobic, thermosetting acrylate type third-generation infiltrators have been introduced one after another. The infiltration method and process have been continuously improved, and the infiltration equipment is developing towards large-scale and semi-automatic, which further promotes the wide application of infiltration technology, which has been recognized by the military industry and cutting-edge technology departments of advanced industrial countries. The application of infiltration technology promotes the thin-walled design of many complex structures. At present, some foreign enterprises have taken the infiltration technology as a design means and an indispensable production process in the production of castings, and advocated the full treatment of castings by infiltration. High infiltration efficiency and remarkable economic effect of infiltration treatment have made people realize the value of vigorously promoting this technology in industrial production

II. Application scope of infiltration technology

1. Casting infiltration

the main function of casting infiltration is to seal and prevent leakage, so that it can be used in hydraulic system and gas system. For example, automobile and tractor gearboxes, fuel pumps, hydraulic valves, carburetors, oil cylinders, compressors and hydraulic components, closed aircraft instruments and their electronic instrument shields, pneumatic parts and various pneumatic instruments

casting infiltration can also prevent internal corrosion and improve production. As we all know, the internal corrosion of castings often starts from the micropores. When the micropores are filled with impregnating agent, after it solidifies, it can prevent the immersion of corrosive liquid and play an anti-corrosion role

in addition, casting infiltration can also be used to prepare for surface treatment such as electroplating and painting. The infiltration agent fills the gaps in the casting, avoiding these gaps from absorbing the electroplating solution and causing bubbles and clean surfaces after plating

infiltration can be used as a remedy for defects such as porosity and microporosity in castings and die castings. It also promotes the thin-walled and lightweight design of castings and saves material consumption

2. Infiltration of powder metallurgy parts

powder metallurgy materials have excellent performance. At present, powder metallurgy materials are widely used in the manufacture of lining kits for automobiles and tractors, valve guides, gears, cams, bearing shells, clutch friction plates, electric heating elements, heat exchangers, cutting tools, tools and dies, and some corrosion-resistant, high-temperature oxidation-resistant and high-temperature resistant parts

powder metallurgy parts (hereinafter referred to as powder metallurgy parts) are made of metal powder (or mixture of metal and non-metal powder) as raw materials, pressed and sintered into various types of workpieces. Powder metallurgy parts are characterized by many pore networks in the small air gap between powder metal particles (accounting for about 15% of the volume of the whole workpiece), which still exist even in high-density powder metallurgy parts., Powder metallurgy parts cannot be preserved as liquids. The infiltration treatment of powder metallurgy parts can make its internal pores completely filled with infiltration agent to achieve permanent sealing. It can be used in hydraulic systems, such as precision oil pump coupling parts, compressor housing, etc

in addition, the electroplating solution and cleaning agent will not be sucked into the pores before electroplating or other surface coating treatment of powder metallurgy parts. China has reached the international level in the research and development of many materials, and can obtain smooth and corrosion-resistant workpieces

it must be pointed out that the powder metallurgy parts should be infiltrated immediately after sintering, because at this time, the pores are clean and easy to be completely filled by the infiltrating agent. After infiltration, powder metallurgy parts can also improve their cutting performance (the tool will change from intermittent cutting to continuous cutting after microporous filling), which is convenient for process control

3. Infiltration of electronic devices

infiltration of electrical components such as transformers, capacitors and motors can increase their dielectric and insulation properties. For example, after the assembly of motor stator and shell, the components form a single whole through infiltration. After infiltration, the micropores are sealed, and a certain strength and heat dissipation effect are increased, which solves the problem of motor vibration and reduces the insulation performance. At the same time, after infiltration, the motor can still maintain good insulation performance in a humid environment, and improve the reliability and service life of the motor

4. Infiltration of non-metallic parts

non metallic materials, such as wood (sleepers, electric poles, etc.), ceramics and fiber plastic synthetic materials, can prolong their service life and improve their water resistance by using infiltration treatment. For example, large computer cooling system parts are generally made of FRP reinforced plastic, which can be effectively sealed by infiltration and prevent leakage due to the passage of liquid micro reinforced fibers

it can be seen from the above that infiltration technology has a wide range of applications in mechanical and electrical products and porous material seals

III. infiltration method

infiltration treatment method. The above is the defect nature and distribution state of the three purchase standards of the electronic tensile testing machine, the working condition of the workpiece, the structural size and the type of infiltration agent, etc., and different infiltration methods are selected

at present, the most commonly used and effective method for overall infiltration is vacuum pressure infiltration method. Japan Sanjie company and plaselam company are engaged in the research and development of infiltration technology, supplying infiltration equipment and a series of infiltration agents to countries all over the world, and providing infiltration technology services. Loctite impregnating agent meets mil-scd27680 and mil-b standards of military industry. In Japan, this technology is widely used in pressure parts in various industries, and several major Japanese automobile companies take casting infiltration as an indispensable process in engine production. For example, Japan's r.s.t company has adopted infiltration technology to provide engine aluminum castings to dozens of automobile companies, which has reduced the scrap rate of aluminum castings from 16% to 3%. Therefore, the factory has reduced the loss of about 70 million yen per month. Ronceray company in the UK processes about 40000 tons of castings every year with the infiltration method that causes the change of sensor output voltage, and GE company in the United States manufactures insulation motors with vacuum pressure infiltration method, which has achieved great economic benefits. Hundreds of factories in China have used infiltration technology, which has achieved considerable economic and social benefits

conclusion:

⑴ the production practice of infiltration technology has proved that it has certain practical significance and broad prospects in the national economy. This technology adopts vacuum pressurization process, which is feasible, reliable and effective. It is a new technology to solve the pressure bearing sealing of castings

⑵ QH type infiltration equipment is a relatively perfect equipment in China at present, which can meet the requirements of infiltration process. In terms of performance and function, it has reached the domestic advanced level and the international advanced level

⑶ TT series inorganic infiltrators can be used under various working conditions with ideal effect, and their performance is better than that of domestic products of the same type

⑷ the organic infiltration agent tietai 90C is the latest formula and latest development achievement in the world, and is widely used in the domestic market at present