Contrastive Investigation Into Hydrodynamic Suspension Ultra-smooth Processing Different Material

Reviewing the past 20th century, the humanity has obtained each significanttechnology achievement, which is correlative with manufacturing technology,especially with ultra-precise processing technology. The ultra-smooth surface hasan important role in the modern optics, the photoelectron discipline, the defenseindustry, the ultra-precision mold manufacture field. The corresponding ultrasmooth processing technology also becomes the important sector in the modernultra precise processing technology. With the development of the science andtechnology, the new requests are proposed in many ultra smooth surface fields, andit is more and more harsh to their surface roughness. Many countries scientistshave done the massive work on it, and have proposed lots of the new methodswhich obtains the ultra smooth surface. But those methods are mostly improvedthrough the traditional adhering abrasive polishing or the dispersible abrasivepolishing. For example: the mechanical chemistry polishing, the elastic ejectingprocessing, the magnetic fluid polishing, the plasma assistance polishing and so on.The suspending liquid flow processing is a kind of advanced ultra smooth surfacemachining technology in the last few years. This article researches the suspensionprocessing ultra smooth processing different material from theory and experiment.Several important works has been done in the paper as follows:The paper elaborates (such as fig. 1) the ultra smooth free curved surfacehydrodynamic Suspension processing system which is based on the robot platform.This system is composed by the YR-SV3-J00 robot, the processing equipment, thespeeder, the computer and two degrees of freedom XY work table. Moreover, afterthe robot is installed the equipment, the robot cannot have no restraints at willmovement because of the equipment structure relations, and the robot work spacehas received the some limit. Therefore, the paper has introduced the XY work table,and satisfies the processing through the increase redundant degree of freedom.When the work piece is processed without changing the robot posture condition, itmay expand the system the processing scope by the motion which is provided bythe XY table.Based on the principle of the dynamic pressure and the elastic ejectingprocessing, the paper constructs the hydrodynamic suspension processing system,the grinding compound abrasive assumes the suspended state in the processingfluid, because the finishing tool high speed revolves but along with the fluidtogether movement. Is approaching the work piece surface the small region toproduce the fluid to move the pressure, the abrasive has combined action and so onelastic launch, machinery impact to the work piece surface.Grinds using the tradition throws the theory and the microscopic frictionattrition theory, has carried on the theoretical analysis to the processing process.The abrasive and moves in the elastic launch presses under the function, possiblyhas the micro cutting and the extrusion function to the work piece surface, manytimes the plastic deformation attrition and the friction corrosion attrition function.According to microscopic friction attrition theory, when processes the grindingcompound abrasive and the work piece surface layer atomic collision, weakens thesurface layer atom unceasingly the binding energy. Thereupon when there is thenext collision, the surface layer atom can fall off. The abrasive in the processingfluid under the centrifugal force function, collides unceasingly the work piecesurface microscopic bulge, thus weakens the surface layer atom unceasingly thebinding energy, and causes the work piece microscopic not to be uneven partiallyis removed by molecular or the atomic magnitude.In the processing process, the abrasive has the continual impact to the workpiece surface, causes the work piece surface to undergo the circulation load,produces in the surface layer cuts the plastic deformation and accumulatesunceasingly, appears the periodic dislocation. In the friction process, the shearingdeformation is unceasingly accumulated, causes under the surface the certain depthFig.1 Schematic diagram of hydrodynamic suspension polishing system based on robot1. robot 2. high speed motor 3. work piece 4. processing tool 5. processing fluid 6. XY work tableplace to appear the dislocation to pile up, then causes to form the crack or the hole.The crack along is parallel in the certain depth extends in the superficial direction,after crack expansion arriving length, work piece surface material by atomic levelflaking or realization atomic shell plastic flow.The abrasive transmits the energy is moves with the processing fluid presseswith the velocity correlation, processing fluid flowing is the finishing tool highspeed revolves causes, therefore the abrasive speed is and the finishing toolvelocity correlation. To moves presses the distribution situation and the singleabrasive stress analysis carries on the analysis, like chart 2, chart 3 shows. Alongwith work piece surface stress increasing, the work piece surface possibly has theplastic deformation, enough great time may destroy the surface layer atom withnext atom between union, realization surface layer atom removing, the reactionshows more greatly on Italy can go to remove more quantities the atom.The nanometer level abrasive attacks to the work piece surface, while whichremoves by the atomic level is following the plastic deformation occurrence. Whenthe abrasive transmission energy enough achieved when material plastic yieldstrength, the plastic deformation can produce. Because the abrasive hits to time therough peak and the valley the contacted area differently causes the contact stresssize which produces not to be dissimilar, the work piece surface plastic deformationdegree is dissimilar, but in the overall the surface roughness is reduces.The paper analyses processing material mechanics performance to face workeffect influence by using materials science correlation theoretical. Namely thematerial elasticity coefficient, the binding energy (chemic bond energy) theequipollent study performance have the influence to the work piece face workeffect.The hydrodynamic suspension processing fluid is composed by nanometerparticles, the basic-carry fluid and the surface active substance. The paper selectsthe mohs rigidity 9 SiC nanometer particles, it not only has the characteristic of thehigh degree of hardness, good chemical stability, wear-resisting, the hightemperature resisting, but also the particles are extremely small. The base carriesthe fluid general request very good thermostability, the volatility low, the suitabletemperature difference is wide, we select the different viscosity 30# lubricating oilto carry the fluid as the base. This experimental choice polymethyl acrylic acidamine PMAA-NH4 takes the surface active agent. It individually the nanometerSiC particle superficial gable will get up, causes it each other to separate, aerosol influid. The processing fluid which we obtain has the good fluidity, the stability andthe dispersibility, which suits in the hydrodynamic Suspension processing.The surface roughness survey uses WYKO and the atomic force microscopetwo kind of instruments, when with WYKO examination, after can the moreobjective reflection work piece processing surface roughness situation, but atomicforce microscope then pays great attention to the superficial appearance the detail,has the help regarding the research processing mechanism;To each work piece,evenly selects three regions in the surface to carry on the survey;After theprocessing, uses the high-purity ethyl alcohol to the work piece to carry on theclean.In has carried on in the theoretical analysis foundation to the processingprocess, in order to explore the effect which the hydrodynamic Suspensionprocessing the validity and can achieve, has conducted the massive liquid flowshydrodynamic Suspension processing experimental study, has completed to workpiece the and so on optical glass K9, 45 carbon quenched and tempered steel andCr12MoV molding tool steel contrast experimental study and analyzes,experimental result as follows:Obtained the change process period parameter to (three kinds) the work piecesurface roughness change influence rule, the work piece surface roughness butreduced gradually along with the process period, but when the process periodpassed through after 60 -90 minute this sector, the surface roughness value hadachieved the hydrodynamic Suspension processing limit, namely the surfaceroughness value basic maintenance was invariable;The experimental resultindicated the hydrodynamic Suspension processing technology could realize to theK9 glass, the Cr12MoV molding tool steel and 45 carbon quenched and temperedsteel work piece nanometer level removes, obtains the nanometer level ultrasmooth surface, after the processing the work piece surface quality obtains theenhancement, the surface roughness reduced generally, the effect was obvious. Atthe same time had also proven we develop the processing fluid regarding the liquidflow aerosol processing also is suitable.The paper has obtained the change process period parameter to process thefluid temperature change the influence rule. May see from the above three groupsof experimental result, in other condition same situations, knew from thethermometer measurement result, the processing fluid temperature when elevatesalong with the process period increase, surpasses 60 min after, the temperaturebasically maintains at 45 this scopes. Moreover, each group of experimental workpiece surface quality quickly enhances, the superficial three dimensionalappearance improvement is most obvious, roughness value drops quickly,roughness obviously reduces all occurs in the processing fluid temperature is in 45about this scopes, in this temperature range, the work piece can realize an Asianmicron magnitude to remove well, obtains the nanometer level ultra smoothsurface.Confirmed the work piece different region surface roughness value (workpiece center region to take, symmetrical edge took two) changes the rule isdissimilar, the experimental result for dropped much in the pressure high centerregion roughness value, but dropped in the entrance and outlet pressure smallregion roughness must be few relatively, the experimental result indicated inprocessed in the region along with pressure increasing, the processing effect wasbetter, with the front theoretical analysis result was consistent.The experimental result indicated that, the hydrodynamic Suspensionprocessing technology is one new ultra precise processing method, it may realizeoptical glass K9 and so on metal material surface a and so on brittle material,Cr12MoV molding tool steel and 45 carbon quenched and tempered steelnanometer level removes, causes the surface to obtain the nanometer level ultrasmooth level, at the same time proved the hydrodynamic Suspension processingtechnology suits to optical glass K9 and so on the brittle material carries on theprocessing, the effect is more obvious. Moreover, this experiment also for finallyrealized the ultra smooth free curved surface hydrodynamic Suspension automaticprocessing to provide the foundational empirical datum.