Thermal spraying technology introduces

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Summarizing thermal spraying is a rehabilitate is mixed protect a technology beforehand, the development as modern science and technology and rise, the performance characteristics demand that produces equipment and mechanical component to industry is higher and higher also. Whole is cast or forging costlier metal, like titanium, nickel, cobaltic, tungsten, zirconium, wait for cost very tall and casting, forging and solder the method has certain difficulty, make the appearance in the labour of average data then, spray a special coating, make its achieve: Anticorrosive, wear-resisting, decrease grind, fight high temperature, fight oxidation, adiabatic, insulation, electric conduction, prevent microwave radiate to wait a series of a variety of functions, make its obtain managing data, the purpose of managing the sources of energy. Defining thermal spraying is to point to use oxygen, the wave of acetylene blaze, electric arc, plasma arc, explosion spray unit that offers different heat source, blaze of high pressure of generation high temperature flows or supersonic speed blaze flows, the material of solid state spray of all sorts of the composite material that if all sorts of metals, pottery and porcelain, metal adds pottery and porcelain,will make the material of coating, plastic powder, the instant heats model condition or melt condition, high speed spray arrives through pretreatment (clean and coarse) a kind of surface that component surface forms coating machines a method. We make special working appearance " coating " , call the working method of production coating " thermal spraying " , it is the floorboard that uses all sorts of heat source to undertake spray and gush solder. The history heats up besmear technology most antedate to was invented by general doctor 1910, name at that time: "Metal spray " American METCO company was published first 1943 " metal spray " American METCO company published manual the 7th times 1959 incognito " flame spraying " manual in September 1973 10, meeting of thermal spraying of the 7th concerned international is held 14 days in British London, incognito " metallic spray " September 1979 27, will be in the United States on October 1 Florida city one famous city of recreational ground Miami holds meeting of thermal spraying of the 8th international, use " thermal spraying " , this one noun, this is " thermal spraying " substantival origin. Technology of our country thermal spraying begins from the fifties, home was established in Shanghai by Wu Jianchun and Zhang Guanbao at that time the first specializations spray factory, develop gush of silk of oxygen acetylene blaze and electric gush device, begin metallic spray professional work external. Technology of our country thermal spraying starts earlier, 50 time developed spray of filar material electric arc; Branch of certain war industry begins 60 time research plasma spray, temperature of plasma arc blaze is high, etc from fly at spray grain rate is rapid, coat tie strength is higher also (40 ～ 80MPa) , hole rate is less than 5 ％ , get applied extensively in branch of our country war industry; 70 time appeared the spray facility with breed and relatively complete model and material, but make progress as a whole slow, just arrived to just obtain rapidder development in last few years. Especially former state classics appoint after popularizing thermal spraying the project as national emphasis, development speed obtained remarkable economic benefits more quickly. In October 1981 21, 27 days by national classics appoint, state committee of science and technology is chaired meeting of thermal spraying of first whole nation was held in Beijing, announce on the meeting by national classics appoint held water below the leader " group of coordination of countrywide thermal spraying " , hang rely on Beijing mine smelt metal to study total courtyard, synergic group contacts national classics trade to going up appoint, to issueing connection each save city, municipality classics appoint bureau of science and technology of departmental door of division of science and technology, and large and medium-sized unit of enterprise, universities and colleges, scientific research form cross a region, cross a trade, cross a branch system of network of technology of promotion application thermal spraying, unit of existing party member 400 many. Material of Wuhan of national Electromechanical ministry protected an institute to applied for to hold water to ministry of national civil administration 1991 " committee of major of thermal spraying of association of Chinese surface project " , it is the trade organization that the business that the whole nation pursues exterior project and relevant unit form of one's own accord, hang now rely on institute of Beijing agriculture machinery, the member that already developed round experience reachs the member outside the condition more than times 400 more than 150. Thermal spraying (solder) harder than eletroplating chromium has following advantage (1) to same productivity, plating hard chromium and the capital construction charge of the plating that heat up dip and energy cost should be gotten high much. (2) to coequal productivity, thermal spraying place needs field to have a few of plating hard chromium and hot dip plating only. (3) chromic price is more expensive than other material, and the market is supplied still very in short supply, the data that thermal spraying uses is extensive, a lot of material compare hard chromium more wear-resisting. (4) the cost of waste liquid processing of plating hard chromium is higher and higher, and thermal spraying does not have problem of social effects of pollution. (5) it is OK that plating hard chromium can be used at conductor to mix only put the work inside plating chamfer, and the workpiece of thermal spraying does not suffer material to pledge with geometry appearance is restricted, apply to the metal with big random and spray of surface of metalloid structural member almost, also can undertake local spray to all sorts of large work, can machine indoors already, but outdoors spot spray works, if use corresponding craft to be able to be in,all sorts of metals of different function, pottery and porcelain, metal adds the matrix surface spray such as all sorts of metals, pottery and porcelain, glass, black lead, cement, plastic, lumber the composite material of pottery and porcelain, but spray the coating of all sorts of plastic and pulverous material. (6) thermal spraying layer can restore all wearing away not only dimension of component of machinery of out of tolerance, can make any metals and metalloid material surface compound again, aggrandizement of exterior modified, surface, make its achieve: Anticorrosive, wear-resisting, decrease grind, fight high temperature, fight oxidation, adiabatic, insulation, electric conduction, prevent microwave radiate to wait a series of a variety of functions, make its obtain managing data, the purpose of managing the sources of energy. Make thereby component of all sorts of mechanical equipment, car " lengthen life delay year " , the component that makes discard as useless " bring the dying back to life " . Coating and ≥ of matrix union strength 6.

5 ～ 10kg/ Mm2, gush solder layer and matrix combine intensity ≥ 45kg /mm2, coating hardness from 15 ～ 69HRC, coating surface roughness is Rz25 ～ 100um, coating ply 0.

3 ～ 15mm, coating classics the surface roughness after machining is recoverable to Ra0.

8 ～ 0.

2um, can satisfy different technique requirement. (7) with eletroplate or photograph of brush plating craft is compared, the coating deposit rate of thermal spraying is high, operation time is only those who eletroplate hundreds of 1/0. (8) in spray of surface of average data matrix precious metal reachs functional material, or place of key of product of spray of choice actor simple stuff, if chemical stainless steel reacts boiler can use carbolic steeliness to build, the job expresses material of face spray stainless steel, but the facility cost that big political integrity restricts you, improve product quality, prolong service life. (9) the component of all sorts of large and crucial equipment and foreign import local damage change without spare parts, or make hard and the component with high value, use thermal spraying rehabilitate to have the handy, reliable, quick, pecuniary loss that can reduce to be caused to the factory because of shutdown stop production. (10) this technology has facility simple, investment little, cost is low, get effective fast, benefit the characteristic with tall, extensive use. In recent years, the pottery and porcelain in thermal spraying material and plastic material got take seriously and developed corresponding flame spraying device; Should special those who point out is, the flame spraying technology that comes out the earliest, in the thermal spraying technology of flying development, not only was not washed out, relay through improving the spray that getting used to of all kinds material ceaselessly add develops however. The occurrence of all sorts of new-style spray material, enlarged the scope of application of flame spraying technology further. Gun of new-style flame spraying not only can all sorts of metals, pottery and porcelain, metal adds spray the coating of all sorts of the composite material of pottery and porcelain, plastic and pulverous material. Although plasma is mixed the flame spraying of coating excel convention of HVOF/HVAF supersonic speed and explosive spray, but because invest big, operation to control a system ponderosity of complex, equipment, cannot spot construction, applied limits gets great limitation, in in anticorrosive popularize hard with maintenance market, equipment of new-style flame spraying and technology and equipment of spray of supersonic speed electric arc and technology are in industry is anticorrosive mixing is main technique force forever in market of spare parts rehabilitate. The thermal spraying of world of existing state of affairs of development of our country thermal spraying already had history of 100 years, chinese thermal spraying also has history of nearly 50 years. Come nearly 20 years especially, chinese thermal spraying had greater progress and development, below, the respect such as overall level and position, equipment and material, application, scientific research and development makes simple introduction. 1.

Overall level and position occupy not complete count, in " 85 " during (1991 ～ included 1995 1996) , total production value of industry of Chinese thermal spraying is controlled for 300 million the first year of an era or the reign of an emperor (include material of thermal spraying equipment, material, construction and technical service, auxiliary equipment to wait) . 1996, total production value of economy of our country countryman is about 7.

5 trillion yuan (it is 910 billion dollar about) , thermal spraying production value occupies his about 0.

39/10000 ＞ . According to association statistic, countrywide thermal spraying from personnel of course of study 3000 people are controlled (do not contain construction group casual) , the unit that pursues thermal spraying job is 300 ～ 350, include construction of manufacturer of thermal spraying equipment, material, subsidiary engine, auxiliary material, thermal spraying, technology to serve an unit, and unit of the scientific research that pursues thermal spraying, education, development and trading company. Thermal spraying enterprise still a kind of small-sized unit (30 people of ﹤ ) give priority to, occupy the 90% above of gross. Is production value of average per capita of thermal spraying industry 100 thousand yuan about / person? Year, the person that outstanding is belonged to in mechanical industry (classy level) . Concern material introduction according to abroad, in last few years total production value of American thermal spraying is 2 billion dollar about, japan is 80 billion yen, hold total production value of its countryman economy respectively (GNP) 3.

6/10000 and 2.

3/10000. The ratio that thermal spraying production value weighs in GNP is this country thermal spraying develops important sign. This ratio of China, 11% what be the United States only, 17% Japanese. This explains, chinese thermal spraying still is in development phase, far did not reach maturity and saturated level, also because such, the market that thermal spraying is in China is broad, good luck is very much, development foreground is valued. 2.

Thermal spraying equipment and the material own development through a few years and introduce, draw lessons from foreign advanced technique, current, china already can be developed and equipment of spray of wire of spray of powder of spray of spray of manufacturing vacuum plasma, atmosphere plasma, explosion, plasma v, electric arc, blaze, blaze, manufacturing metal is pulverous (Ni, Co, Fe radical, aggregate make an appointment with 300t/ year) , pottery and porcelain, cermet is pulverous (Al2O3, Al2O3+TiO2, cr2O3, WC, Co, aggregate make an appointment with 200t/ year) , filar material (Al, Zn, Cu, stainless steel, aggregate make an appointment with 1000t/ year) . Although equipment is overall level still not tall, data still exists such or in that way quality problem, but, china already became a few on the world a few to be able to be on thermal spraying equipment and material one of countries of autarky, satisfy the need of thermal spraying industry basically. In the meantime, the facility that has 10% about and material still need an import. 3.

The application of thermal spraying technology is current, thermal spraying technology has gotten comparative wide application in China, main applied field has aviation, spaceflight, steely, petrifaction, steel structure anticorrosive, mechanical, light industrial, spin, papermaking, the sources of energy, shipping, total production value makes an appointment with 200 million yuan / year. The thermal spraying application of our country has the following characteristic: ⑴ application range is big, quite high level is had in certain domain, like aviation engine (cooperate with Boeing) , roller of annealing furnace hearth, galvanization guides roller (steely industry) , valve (petrifaction industry) , pull silk to guide the roller, cone pulliy, circle that pull silk (textile industry) , high-grade glass mould (light industrial) , spiracle (automobile industry) etc. The technology that ⑵ uses and data are extensive, the thermal spraying technology that uses on international at present almost and material, china is being used, if true cool one's heels is ionic spray of spray, atmosphere plasma spray, explosion spray, supersonic speed flame spraying, electric arc, blaze is pulverous remelting of v of spray, plasma, laser, vacuum (protect atmosphere) remelting. ⑶ is engaged in thermal spraying application (Job Shop) enterprise with medium and small businesses (<30 person) give priority to, the number occupies the 2/3 of gross, production value occupies the 75% above of total production value. Share collaboration makes enterprise, private company, cooperative occupy quite specific gravity, close, solely invested enterprise begins to appear. The maintenance means that ⑷ regards equipment, component as with thermal spraying develops quite, to enterprise of medium, small thermal spraying character, the job of half above is to be aimed at repair. The relevant and professional lab of place of courtyard of ⑸ scientific research, universities and colleges, staff room, if solder (occupy most above) , the major such as treatment of material, surface, enter market of domestic thermal spraying actively. The main technique force of our country thermal spraying also is in afore-mentioned units. Current, the main problem that in application the respect exists is, dimensions discretion of small, level is not neat, lack unites management and standard, cannot form in the company of thermal spraying bibcock that has force domestic and internationally (the SNMI of the Praxair of the Tocal that is like Japan, United States, France) . CNC Milling