The fuel economy of current engine and environment are friendly the gender is taken seriously increasingly, with litre of power of engine ceaseless promotion is setting, reduce piston annulus and air cylinder wear away, perhaps say not to let this kind wear away to rise and increase as what raise power at least, make the task that is worth to take seriously. The chromium that the article introduced Federal-Mogul company to be developed for the piston annulus of the first chamfer - diamond coating GDC, this is the chromic coating craft of grain of a kind of built-in diamond, can offer to reach the highest bear of engine additional power reserve. Generally speaking, should make the fuel of new-style diesel engine is used up with harmful material discharge reduce a minute, the heat of component / mechanical bear can increase one minute accordingly. Especially for secondary to the attrition between piston annulus and air cylinder wall system, this one expression particularly apparent. The diesel engine of current power aggrandizement can achieve quite high ignition pressure, form high temperature from this, these ask to compress annulus to be able to bear high load capacity. Come for years, chromic - CKS of system of coating of pottery and porcelain already got admissive in practice, the engine model that producing for great majority supplied enough safe reserve indeed. This is a kind of root at alumina (Al2O3) the technology of grain, connect those who cross multistage to eletroplate solid of anchor of grain of craft general alumina is in a kind of hard chromic matrix textural. its chromic coating relative to Yu Chuncui, be able to bear or endure as a result of what component of pottery and porcelain can raise pair of ablation get ability, achieve thereby reduce effect of coating itself tatty. However, right up to now technical development trend undertakes analytic can discovering, piston annulus / the heat of secondary system of attrition of air cylinder wall - mechanical bear still has the tendency that rises further. This is meant, appear to what nod corrode very as the formation of ablation, the problem of tribology respect can upgrade probably subsequently. The grim challenge that must face will include: Taller and taller service requirement (commercial vehicle domain also is such) , high temperature and increasingly the price scissors between reductive lube supply. Forthcoming tribology load is calling the occurrence of new-style coating system. If pursue 1, federal-Mogul company uses the chromium that is based on diamond - development of GDC of diamond coating system goes a kind of new coating type, already used at the car diesel engine that produces group by group and commercial vehicle diesel engine at the beginning of 2004. Graph the 1 chromium below multiple of 200 times enlarge - diamond coating surface: The hemal state network that built-in diamond grain forms is clear but the piston annulus coating of built-in diamond is in differentiate affirmation gets in embedding the craft of some kind of grain been experimentinging in hard chromic layer. To the formation of coating structure the process can be controlled first-rately, and embed grain is in eletroplate of chromic layer good mechanical anchor is had in showing micro-crack reseau firm action, be helpful for obtaining a more solid job surface. To heighten the effect of this kind of coating, chose a kind to exceed careful and built-in grain. Face come high the limiting temperature of 500 ℃ , the hardness of the diamond grain of working surface withstand test, its are able to bear or endure the ability that gets ablation and wearability are apparent excel is chromic - coating of pottery and porcelain. Graph 2 chromium - coating of pottery and porcelain (left) with chromium - diamond coating (right) in the granuality of built-in grain pursues quite the extreme condition in high pressure of engine high temperature dismantles the 3 structures that contain the hard chromic matrix that shows micro-crack reseau to be used at built-in diamond grain, diamond can transform initiatively black lead. When moving normally, hard diamond coating can get used to the Gao Zaihe below normal moving condition; And when load of occurrence punctate peak value, the black lead that can appear to be transformed by diamond, form solid contact through black lead below the circumstance of lubricant inadequacy then, achieve the lubricant performance below emergency then. From this knowable, make as a result of material nature like that, the function characteristic of two kinds of mutual contradiction realized perfect union through diamond material, gift chromic - diamond coating system is very expensive bear the weight of function. Chromic - diamond coating and chromium - of coating of pottery and porcelain different, on the granuality that expresses built-in now grain above all. Chromic - the granuality of built-in grain is in coating of pottery and porcelain 2 with 5 μ M between, and use as the granuality of built-in grain is in diamond 0. 25~0.
Between 5 μ M, than former small much (graph 2) . In addition, in show micro-crack reseau respect to also have a difference: If say in principle, shang Yuge of its coating structure - if system of coating of pottery and porcelain agrees basically, differ somewhat in the respect that how embeds, from the graph 3 visible, chromic - in diamond coating system, exceed careful diamond grain to embed addly in a kind of when show micro-crack reseau interior special matrix. The technological process that fashions coating is: 1.
Have coating deposit through forming crackle and matrix structure; 2.
Open shows micro-crack reseau; 3.
Buy enters diamond grain; 4.
Close show micro-crack; 5.
Build next coating. Chromic - the moving character of diamond coating is mixed at chromic coating relatively chromic - coating of pottery and porcelain, chromic - surface of job of diamond piston annulus has inferior piston link wear rate and apparent taller be able to bear or endure ablation ability. Graph the face of piston annulus job after 4 engine experiment runs an end is different: Traditional chromic coat; In: Chromic - CKS of coating of pottery and porcelain; Right: Chromic - diamond coating GDC1.
6 crocks of MRD that are used at commercial vehicle to (MRD= medium-sized diesel engine, 12 litres discharge an amount, 577h full load) engine oppose compares an experiment, chromic - what the wearability of diamond coating system compares hard chromic coating is 4 times taller, than chromium - of coating of pottery and porcelain 2 times taller. On other van and car engine, also appear again and again the result of close. 2.
Be able to bear or endure in what high load condition falls ablation ability respect, the situation is roughly same. If say to obvious ablation question appears on the chromic coating in the tradition, so chromic - the preliminary indication that overloads only on coating of pottery and porcelain, and chromic - diamond coating can bear same load and do not give an issue (graph 4) . Graph 5 although rise power to rise ceaselessly, of piston annulus wear away to be in however drop, of gas cylinder bushing wear away to also maintain in original standard chromium - the wear-resisting performance of diamond coating is very excellent, and very strong to engine runs a condition astringently to have be able to bear or endure get ability. So, although litre of power of diesel engine going tall ceaselessly, the wear extent of piston annulus is in however drop. In the meantime, consult foreign data is knowable, piston annulus is chromic - surface of diamond coating job was not brought to air cylinder wear away additionally, go up at the quantitative class of close however, if pursue,5 are shown. The diamond grain that epilogue uses accept rice level regards the job of a kind of hard chromic coating as apparently built-in content, formed those who be used at piston annulus, have be able to bear or endure higher ablation ability and system of coating of inferior oneself tatty. Have the aid of this kind of function, new-style chromium - the requirement that diamond coating system can make piston annulus satisfies prospective diesel engine to rise ceaselessly further, also changing long-term sealing namely, and assure to be discharged inferiorly with oily bad news while, give out to run effect high. In view of this, appropriate of car component industry gives to this kind of craft and material enough take seriously, beginning the research related the hand and development work as early as possible. CNC Milling
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