Theory of exterior surface roughness develops research

Closely related the puts forward to manufacture a technology with development and industry development of the standard of development surface surface roughness of theory of exterior surface roughness and standard, it was experienced arrive by qualitative assess mensurable assess two phase. Exterior surface roughness begins to be noticed above all from 1918 to the influence of function of surface of machine spare parts, in plane and aircraft engine design, because ask to achieve the greatest strength with least material, people begins the knife mark to machining the surface and scratch to try to consider to the influence of fatigue intensity. But because measure difficulty, there is not the assess requirement on mensurable numerical value at that time, just decide according to range estimation feeling. In 20 centuries 30 time of 20 ～ , country of on the world a lot of industry uses trigonometry symbol extensively (▽ ) the treatment surface that combination will come to to express different precision. To study exterior surface roughness is right the influence of spare parts function is mixed magnanimity surface is microcosmic and rough spent need, arrive from 20 time end 30 time, the design of a few experts of the country such as Germany, United States and England made outline recorder, contourgraph, also arise at the same time gave the consumed such as the smooth microscope that cut pattern and interference microscope to learn a method to measure the surface microcosmic and rough exterior instrument, to from numerical value surface roughness of mensurable assess surface created a condition. Since 30 time, parameter of mensurable to exterior surface roughness already assess undertook study, if American Abbott put forward,use the deepness that is apart from top of exterior outline peak and curve of bearing length rate to come token surface surface roughness. Published Schmaltz to discuss the monograph of exterior surface roughness 1936, offerred a proposal to the assess parameter of exterior surface roughness and numeric standardization. But parameter of surface roughness assess and its numeric use, after from 40 time each country corresponding national level is released, making a standard that is accepted extensively truly still begin. It is the United States released ASA B46 1940 above all.

1 state level, edit through a few again later, become active standard ANSI/ASME B46.

1-1988 " surface roughness of exterior structure surface, surface wave grain is spent and machine grain " , this standard uses central line to make, make Ra give priority to parameter; The Russia before catching released GOCT2789-1945 1945 " the surface is bright and clean degree, the surface is microcosmic geometrical appearance, classification and notation " national level, passed 3 times after that edit become GOCT2789-1973 " parameter of exterior surface roughness and feature " , this standard also uses central line to make, set include deviation of outline root mean square (namely present Rq) inside 6 assess parameter and its corresponding parameter value. Additional, the standard of other industry developed country is established in 50 time mostly, the standard of the respect such as the assess parameter that if confederative Germany released DIN4760 and DIN4762 in Feburary 1952,concerns exterior surface roughness and term. The country of above each country used central line to make the computation that regards exterior surface roughness as parameter in the standard, specific parameter differ in thousands ways, but the main parameter that its define still is Ra(or Rq) , this also is the communication between international uses a the most extensive parameter. The basic parameter in standard of 2 surfaces surface roughness defines the development as industry and the need that open to the outside world to cooperate with the technology, the our country research to exterior surface roughness and standardization are taken seriously by science and technology and industrial group place more and more, the situation with the term that is respect of surface roughness of surface of rapid change home and skimble-scamble concept, achieve the function that consolidates with international, our country equivalent uses international Organization for Standardization (the international metric system that ISO) concerns ordered GB3505-1983 " surface of term of exterior surface roughness and its parameter " . GB3505 reached the term such as its parameter technically to make a provision to concerning the surface of exterior surface roughness, have 3 shares among them in all 27 parameter term: A.

With microcosmic and rough the term of parameter of exterior surface roughness that spends high character to concern. The commonly used term that defines among them is: Outline arithmetic is average Ry of the greatest height mixes Rq of deviation of root mean square of deviation Ra, outline, outline microcosmic and rough degree at 10 o'clock 11 parameter such as high Rz. B.

With microcosmic and rough the term of parameter of exterior surface roughness that spends span character to concern. Have outline among them microcosmic and rough the Chan Feng of Lq of wavelengh of root mean square of D of density of peak of spent between-mean distance Sm, outline, outline and outline between-mean distance S in all 9 parameter. C.

With microcosmic and rough the term of parameter of exterior surface roughness that spends appearance character to concern. This has outline degree of skewness among them Tp of rate of length of Dq of slope of root mean square of Sk, outline and outline bearing in all 5 parameter. The content that function of surface of 3 accurate treatment evaluates and its are pressing when putting forward, this one concept begins parameter of sexual surface surface roughness is to study the impact between spare parts surface and its function, realize accurate to exterior form appearance quantified description. Rise as what machine precision requirement and the treatment demand of surface of spare parts of special to having function, the mensurable computation means that offerred exterior surface roughness to evaluate parameter and numerical value set, at the same time this also promoted the formation of national level and international standard and development. In modern industry production, a lot of making the surface is machined and have specific specifications feature, such as: The wearability that makes an appearance, sealing, reflection sex that cooperates property, diathermancy, conductivity and harmonic to the light wave, liquid and gas are the fluidity in mural face, caustic, the exterior function of component of filmy, integrated circuit and man-made organ, the precision that measures instrument and machine tool, dependability, vibration and noise wait a function a moment, and the evaluation of these specifications often relies on the state that makes an exterior feature, have close tie with geometrical structure feature of the surface namely. Accordingly, the core problem that controls treatment surface quality depends on its use function, should the basis is of all kinds the exterior feature parameter that makes the characteristic compasses of an oneself will surely satisfy its to use a requirement. See not hard, to specific treatment surface, we always hope to use most (or quite) appropriate exterior feature parameter goes evaluating it, with period achieve expectant functional demand; At the same time we hope parameter itself should be stable, can reflect the feature of exterior essence, do not suffer assess fiducial the influence that reachs instrument resolution, because undertake measure and bringing parameter indication error to random process,decrease. But from the characteristic that metric system decides and content we discover easily, as the development of modern industry, method of new-style surface treatment appears ceaselessly and measure the application of appliance and measurement technique newly especially, a lot of parameter in the standard already cannot get used to the demand of modern production, close in field of a few special treatment especially, when be like finish machining, the Ra value that with different method treatment gets is same (or very close) not regular meeting has the surface to use a function identically, visible, right now Ra value appears helpless to the assess of this kind of surface, and traditional assess method pays attention to pair of altitude information to do smooth leveling to handle too, and the attribute that ignores horizontal way almost, fail to reflect the comprehensive information of exterior form appearance. Inside the field that researchs in exterior character in recent years, opposite ground says, the research itself about respect of character of function of spare parts surface is relatively fragile, because of it drag in is mixed to a lot of course technical domain. The in use of of all kinds spare parts of the machine has diverse demand each, the functional adaptability that studies exterior feature will be very complex, this also limitted the research of characteristic to exterior form appearance and its function concern. The flying progress that industry produces is pressing need more effective and the occurrence of the parameter of exterior feature evaluation with stronger adaptability, contradict to solve this, a lot of scholars of each country increase research strength in this respect, with period in not far formulate gives the parameter with remarkable character of a function in the future. On the other hand, to prevent " parameter explodes " , also prevent the occurrence of a large number of relevant parameter at the same time, should accomplish will evaluate many function character with a parameter, with the amount a group of very few parameter realize the accurate description of the essential feature to the surface. The core of the assess of appearance of form of new progress surface of theory of 4 surfaces surface roughness depends on diagnostic signal mix without lack fidelity extraction to performance characteristics quantify assess, domestic and international scholar did a large number of works on one hand in this, put forward a lot of depart and reframe method. The development that waits as technology of processing of current personal computer, integrated circuit technology, Electromechanical unifinication technology, appeared to use technology of alignment of way of part of parameter of minute of look doctrine, Motif law, function, time to analyse multinomial of law, least square to draft law of wave of lawful, filter to wait for all sorts of assess theory and method, obtained striking progress, way of part of parameter of the cent look doctrine with opposite and more mature character, Motif law, specific function is faced to undertake introductory below. Theory of geometry of 1) cent form is the closest, the respect such as mechanism of domestic explicit token and the micromechanism that study machine treatment face, contact and exterior surface roughness uses theory of cent form geometry increasingly this one powerful maths tool. Consider to make clear, surface of treatment of a lot of kinds of machine appears a random sex, much measure sex and from affinity, have the main feature of minute of form namely, consequently geometry of use cent form studies exterior form appearance will be reasonably, effectively. The important parameter that determines minute of shape has minute of form dimension D and diagnostic length A, they can measure the irregular sex of outline of machine treatment surface, theoretic do not change along with sampling length change and instrument resolution, can reflect the feature of essence of exterior form appearance, the parameter of assess of exterior surface roughness that can offer a tradition (wait like Ra, Ry, Rz) the information that place cannot provide. The scanning bougie microscope that American TopoMetrix company produces (in SPM) software system, already regarded evaluation surface as one of parameter of microcosmic form appearance cent form dimension. Of the complex structure that machining surface divided form dimension to convey exterior place to have how many and the imperceptible degree of these structures, what imperceptible structure constitutes the opposite bulk of energy in whole face. Cent form dimension is bigger, the structure of regulation of exterior Central Africa is more, and the structure is jumped over careful, the energy that elaborate structure place has is jumped over relatively big, have the capacity of stronger fill space. Mandelbrot put forward the function table of curve of form of a kind of cent to amount to type on Weierstrass function foundation 1982, call Weierstrass-Mandelbrot function, integrate the character of project surface, often write W-M function the form. S N=n1cos2prnx R(2-D)nR>11B=2(D-1)lgA-lg(2lnr)k=2D-5 of Z(x)=A(D-1) ∞ is in Lgs(w)-lgw of double logarithm coordinate, k is slope, w is intercept, from go up the slope that type can see D of cent form dimension is deciding graph line, diagnostic length A and the position that D of cent form dimension is deciding graph line (intercept) . Accordingly to machining surface, can pass its the power table chart below double logarithm coordinate, by (3) type calculates notch form dimension D and diagnostic length A. Cent form theory still has a lot of jobs to remain to study further in applying actually. It is to be not all surfaces to have minute of look feature, cent form dimension whether surface of border of complete list levies in kind, still remain to study further; 2 it is existing the function that distribute form maths model and did not consider the surface is characteristic, also do not have a kind of method to be able to divide form parameter exclusively certainly. The ceaseless progress of 2) Motif law as production technology, exterior quality behaves the appearance error that is the surface, wave to spend not only, the requirement such as exterior surface roughness, and trend of the peak to the surface, cereal and the channel that its form, arteries and veins and distributing wait to also have a demand, need is right undertake integrated assess with the exterior grain structure closely related exterior function. Apparent, the method of is a foundation with 2 dimension parameter assess of exterior form appearance that uses generally now pays attention to high information too, do smooth leveling to handle to high information, and the attribute that ignores horizontal way almost, cannot reflect the face actually form appearance. Motif law is based on geomorphology theory from the surface original message sets out, do not use any outline filter, through what set differs wave of threshold value general is spent and depart of exterior surface roughness leaves come, emphasize the effect of big outline peak and cereal to the function, main outline feature was chosen in assess, and oversight not main feature, this method is introduced surface roughness of surface of French auto industry and wave spend a standard, also already formulate becomes international standard ISO12085. Graph MotifMotif of 1 surface roughness is comprised by the basic outline part between the apogee of peak of two individual outline, the cereal between two peaks is an individual Motif, if the graph is shown 1 times, use the length AR of the parallel total trend at outline, perpendicular the two deepness Hj that always moves toward at basic outline and Hj+1, and the feature measures T(T=min[Hj, hj+1]) token. Below condition of set threshold value, motifs course incorporates ceaselessly, the Motifs that gets assess surface function assembles, the parameter that ISO12085 recommends sees a table 1. Ripple of parameter of primitive outline surface roughness spends the token parameter that expresses 1 Motif law of the between-mean distance AR AWMotif of the Rx Wx Motifs of the biggest deepness of the average deepness R W Motifs of Pt Wt Motifs of parameter outline total height amalgamative should follow 4 conditions, otherwise the peak of 2 photographs adjacent cannot be incorporated, can regard individual Motif as processing only. A.

If the intermediate peak of Motif of two photographs adjacent is more than the peak of both sides,include requirement of subsidiary channels in the human body through which vital energy, criterion 2 Motif cannot incorporate. B.

The length after Motif of 2 photographs adjacent is amalgamative is not more than width condition A(is right Motif) of exterior surface roughness or B(spend) to surface wave, OK and amalgamative. Beforehand surface roughness of OK and detached surface and surface wave spend the maximum A of the Motif width of set, it is threshold value namely actually. The B of set is worth OK and detached wave to spend with rudimental appearance. C.

Enlarge a condition to the height after 2 Motif are amalgamative must is more than or be equal to 2 original Motif. D.

The height of individual Motif must be less than deepness condition 60% of height of the Motif after incorporating. Motif law uses 7 parameter to be able to be spent to exterior surface roughness and ripple only have complete description, it suits to do not have especially beforehand the outline of the journey or defer journey; Undertake on sealed face and process the technology is analysed; The function related to the face of the surface that include sth resembling a net studies; Argue knowledge surface roughness and wave are spent have the outline that is close to wavelengh quite. Motif law replaces sampling length with width threshold value, give automatically end wavelengh, true the local feature that matchs outline, assess parameter is little. But 4 of Motif law amalgamative conditions are to come from old practice work experience, lack academic basis, and three-dimensional Motif still does not have unified definition and amalgamative criterion. Collect of parameter of 3) specific function is in project application, a lot of spare parts surfaces of machine treatment need to have specific functional character, if bearing function, sealing is mixed,lube stops function. Be based on these functional requirement, spare parts surface must be become by design, treatment the application that specific form appearance expects with satisfying. So we are necessary to define specific functional parameter to come to effective ground express the special attribute that asks for spare parts surface, spare parts surface uses angle from the contact (wear away like attrition, lubricant, sealed and close together sex, contact stress, osculatory stiffness, bear the weight of area and thermal conductance) use angle with blame contact (like optical camera lens, the surface is safeguarded and exterior paint is handled) in light of, it is extremely extensive that its ask in the special attribute of functional respect. Exterior characteristic should is aimed at to be able to ask in actual project application collect of set function parameter. More typical is the is based on outline bearing to spend rate curve Rk function parameter that token has face of tall prestressing force collect. In 20 centuries at the beginning of 80 time, trautwein offerred a model of two paragraphs of linear about Abbott-Firestone curve, he shows the trait of crock chamber surface with this model. Return amplify to give to be called from inside this model the liquid stops the parameter of cubage. Recently, again the scholar divides Abbott-Firestone curve into 3 area, offerred Rk parameter market on this foundation, this parameter collect is written formally to take German DIN4776 level. This parameter collect basically is the face that is used at token to have tall prestressing force, wait like honing surface, polishing surface, grinding surface, these relevant parameter spend outline bearing the growth of rate to describe the function of deepness of surface roughness outline, the characteristic of the platform reticulation itself that combines gas cylinder bushing and the working state that enrage cylinder bushing, establish the parameter index that is based on outline bearing to spend rate curve, this assess index can is opposite of outline of surface roughness of the surface inside gas cylinder bushing adjust characteristic, lubricant character, reticulation to distributing wait for the quantitative analysis that undertakes correspondence, realize well and truly description and evaluation air cylinder to cover platform reticulation. Outline bearing length leads curvilinear Tp(c) , call Abbott-Firestone the curve again, it is the main index that describes outline figure. Tp(c) mirrors the wearability of spare parts surface can intuitionisticly, also have important sense to increasing carrying capacity. Moving in cooperating, value Tp is worth big surface, make cooperate the osculatory area between the face to increase, decreased to grind loss, prolong the life of the spare parts. From Tp(c) curvilinear feature can see, it is function of pair of wear-resisting of surface of the aperture inside gas cylinder bushing, lubricant function, the service life port with have very principal. For this set one group is based on outline bearing length to lead parameter market of the curve, correspondence enrages the real work state of cylinder bushing, have quantified description to Tp(c) curve, if the graph is shown 2 times, surface roughness outline and corresponding Tp(c) curve are divided to be 3 parts, it is outline of outline peak, core and outline cereal respectively. Graph the 2 assess parameter A that are based on Abbott curve.

RPK of contracted peak height is the average height of the outline peak that points to upper part of outline of surface roughness core. This one part of exterior outline coping, when engine begins to move, very will fast be worn away, the height of its bring down covers influence air cylinder those who enter regular job state to adjust time, reach real data wear extent. B.

RK of deepness of core surface roughness gives the deepness of outline of core of the rest after outline peak and outline Gu Zhi to be RK in depart. This one part is face of tabulation of permanent worker of gas cylinder bushing, it is affecting the locomotive function of gas cylinder bushing and service life, it is the core part of surface roughness outline. C.

RVK of contracted Gu Shen is to point to from outline of surface roughness core outspread the average deepness to the outline cereal inside material. When the deep groove of these thorough surfaces moves relative to cylinder bushing in the piston, form the oily film with adherent very good function, the wearability that increasing opening, shorten while engine adjusts time, can reduce oily cost substantially. D.

Outline bearing length leads Mr1 with percentage length of denotive outline bearing leads Mr1 is to be to go out outline peak depart the transversal of outline of surface roughness core and affirmatory. Mr1 value is the upper limit that gas cylinder bushing enters area of permanent worker tabulation, its numeric size reflected the treatment level of air cylinder and performance characteristics directly. E.

Outline bearing length leads Mr2 with percentage length of denotive outline bearing leads Mr2 is to be to go out outline cereal depart the transversal of outline of surface roughness core and affirmatory. Mr2 value is the floor level that enters area of permanent worker tabulation, its numeric size not only decided wear extent, still decided the job expresses the lay aside oil of the following deep groove, lubricant ability. F.

Outline of core of surface roughness of V0 of the quantity that keep oil is down outspread the V0 of the quantity that keep oil that be being accumulated to the cross section of the outline cereal inside material is deep trench reticulation actually, the shadow part area that the transversal that it is Tp(c) curve and right x-axis and Mr2 correspondence forms, it has important sense undoubtedly to the lubricant function of cylinder bushing. It is triangular area approximately: V0 ≈ (100-Mr2) × RVK/2. The affirmatory need of the parameter in the graph uses a tropic, the part of the 40% above of tropic is the dot on Tp(c) curve is formed, tropic is worth square in the difference on ordinate direction the smallest, the vertical distance between two node is tropic and x-axis namely RK of deepness of core surface roughness, the transversal position with two corresponding node is the transversal position of correspondence of Mr1, Mr2 namely. To the functional feature parameter of Rk parameter collect, its define a method to depend on dividing Abbott-Firestone curve into the functional area that different share differs with correspondence. Although these methods can use the face of a few projects with specific token successfully, but because it basically is,be based on workmanship experience, lack academic basis, this kind of method can lose original sense when the project surface of other of token great majority. Appearance of form of 5 epilogue surface is affecting the performance characteristics of the spare parts greatly, reasonable the earth's surface is asked for and appearance of assess surface form is a task that has important sense, theory of exterior surface roughness and standard are in inadequacy got tremendous progress inside the time of hundred years, as the development that current personal computer handles technology, integrated circuit technology to wait, appeared multinomial of sequential analysis law, least square drafts way of part of parameter of law of law of wave of lawful, filter, cent look doctrine, Motif, function to wait for all sorts of assess methods, gained a lot of headway, but the finite information that they can get true face only, still put in a few problems to remain to perfect: 1) surface outline is microcosmic the problem of comprehensive and accurate description of statistical feature; 2) surface outline is random process, the value of assess parameter is not certain, arose to measure uncertainty issue from this; The correlation of 3) assess parameter and parameter amount more and more parameter explosion problems; The measurement of 4) surface outline suffers as a result measure fiducial the issue that affects with instrument resolution; Parameter of 5) surface surface roughness and performance characteristics cannot completely corresponding problem. CNC Milling CNC Machining