(完整版)2012毕业设计外文文献翻译.doc

1、毕业设计外文资料翻译题目POLISHING OF CERAMIC TILES抛光瓷砖学院材料科学与工程专业复合材料与工程班级复材 0802学生窦文杰学号指导教师邵明梁二一二年三月二十八日MATERIALS AND MANUFACTURING PROCESSES, 17(3),413401(2002)POLISHING OF CERAMIC TILESC. Y. Wang,* X. Wei, and H. YuanInstitute of Manufacturing Technology, Guangdong UniversityofTechnology, Guangzhou P.R. Chin

2、aABSTRACTGrinding and polishing are important steps in the production of decorative vitreous ceramic tiles. Different combinations of finishing wheels and polishing wheels are tested to optimize their selection. The results show that the surface glossiness depends not only on the surface quality bef

3、ore machining, but also on the characteristics of the ceramic tiles as well as the performance of grinding and polishing wheels. The performance of the polishing wheel is the key for a good final surface quality. The surfaceglossiness after finishing must be above 208 in order to get of grinding and

4、 polishing wheels for all the steps will achieve shortermachining times and better surface quality. No obviousrelationships are found between thedecoration material for floorsand walls ofmaterial than general vitreous ceramic tiles as they can*Corresponding author. E-mail:401Copyright q 2002 by Marc

5、el Dekker, Inc.differentcolors.Gr indingandpolishingofceramictilesplay an important role in the surface quality, cost, and productivity ofceramictilesmanufactured for decoration. The grinding and polishing of ceramic tilesarecarriedout inone pass through polishing production line withmanydifferentgr

6、inding wheels or by multi passes on a polishing machine, where different grinding wheels are used.Most factories utilize the grinding methods similar to those used forstonemachining although the machining of stone is differentfromthatofceramictiles.Vitreous ceramic tiles are thin,usually 58mm in thi

7、ckness, and are asinteredm a t e r i a l , w h i c h p o s s e s sg e n e r a l , t h esintering process causes surface deformation in the tiles. In themachiningprocess,theceramic tiles are unfixed and put on tables. These characteristics will causee a s y breakage and lower surface quality if grind

8、ing wheel or grinding p a r a m e t e r s a r eunsuitable. To meet the needs of ceramic tiles machining, the machinery,grindingparameters (pressure, feed speed, etc.), and grinding wheels (type andmeshsizeofabrasive, bond, structure of grindingwheel, etc.) must be optimized.Previousworksreportedin t

9、hefieldofgrindingceramicands t o n e 1 4.O n l y af e wr e p o r t sgrooves, craters (pores), and cracks are of major concern, which dependsonthemicro-structureof theceramic tile,the choice ofgrindingwheel andprocessingparameters, etc. The residual cracks generated during sintering and roughgrinding

10、processes, as well as thermal impact cracks caused by the transformationofquartzcrystalline phases are the main reasons of tile breakage during processing.Surfaceroughness Ra and glossinessare different measurements of the surfacequality.Itissuggestedthat the surface roughness can be used to control

11、 the surfacequalityofroughgrindingandsemi-finishgrindingprocesses, andthe surfaceglossinesstoassess the quality of finishing and polishing processes. The characteristicso f t h e grinding wheels, abrasive mesh size for the different machining steps, m a c h i n i n gtime, pressure, feed, and removin

12、g traces of grinding wheels will affect the processing of ceramic tiles9.In this paper, based on the study of grinding mechanisms of ceramic tiles,themanufacturingofgrindingwheels isdiscussed. Theactionsandoptimizationofgrinding and polishing wheels for each step are studied in particular for m a n

13、u a l p o l i s h i n g machines.GRINDING AND POLISHING WHEELS FOR CERAMICTILEMACHININGThe machining of ceramic tiles is a volume-production process that uses significant numbers of grinding wheels. The grinding and polishing wheels for ceramic tile machining are different from those for metals or s

14、tructural ceramics.In this part, some results about grinding and polishing wheels are introduced for better understanding of the processing of ceramic tiles.Grinding and Polishing WheelsCeramic tiles machining in a manual-polishing machine can be divided intofour stepseach using different grinding w

15、heels. Grinding wheels are marked as 2#, 3#, and 4# grinding wheels, and 0# polishing wheel; in practice, 2# and 3# grinding wheels are used for flattening uneven surfaces. Basic requirements ofrough grinding wheels are long life,order to increase the performance sucha se l a s t i c i t y ,e t c .

16、,o ft h eg r i n d i n gwheel, the bakelite is always added. The 4# grinding wheels must be able torapidlyeliminate allcutting grooves and increase the surface glossinessof theceramictiles.The 0# polishing wheel is used for obtaining final surface glossiness, which is made of fine Al2O3 abrasives an

17、d fill. It is bonded by unsaturated resin.Thepolishing wheels must be able to increase surface glossinessquickly andm a k e t h e glossy ceramic tile surface permanent.Manufacturing of Magnesium Oxychloride Cement GrindingWheelsAfter the abrasives, the fills and the bond MOC are mixed and poured int

18、o the models for grinding wheels, where the chemical reaction of MOC will solidify theshape of the grinding wheels. The reaction will stop after 30 days but the of fill w i l l a f f e c t t h e i r g r i n d i n g a b i l i t y . A l l t h e factors related to the chemical reaction of MOC, such as

19、the mole ratio ofMgOMgCl 2, the specific gravity of MgCl 2, the temperature andMOC is useda st h eb o n df o rt h eg r i n d i n gw h e e l s,r e a c t i o ntakes place between active MgO and MgCl2, which generates aproductw i t h st a b l e p e r f o r m a n c e i s f o r m e d. T h e b o n d i s c

20、omposed of 5MgeOH T2·eMgCl2 T·8H2O and 3Mg eOH T2·eMgCl2 T·8H2O:Astheformer is more stable, optimization of the mole ratio of MgOMgCl2toproducemore 5Mg eOH T2·eMgCl2 T·8H2O is required. In general, the ideal rangeforthemole ratio of MgOMgCl2 is 4 6. When the contents of

21、 the active MgO andMgCl2 are known, the quantified MgO and MgCl2 can be calculated.Active MgOThe content of active MgO must be controlled carefully so thatr e a c t i o n c a n b esu cc essf u l l y co m p l e t ed w i t hm or e5 M g e O H T 2 · e M g C l 2 T · 8H2O:I fthecontent of active

22、MgO is too reaction timewill be tooshortwith a large reactioncause generation of cracks in the grinding wheel.Onthecontrary, if the content of active MgO is too low, the reaction does not go tocompletion and the strength of the grinding wheel is decreased.Fills and AdditivesThe fills and additives p

23、lay an important role in grinding wheels. Some porous fills must be added to 2# and 3# grinding wheels in order to improve thecapacity to contain the grinding chips, and ensure the strength of grinding wheels in processing under water condition. Some fills are very effective in increasing the surfac

24、e quality of ceramic tile, but the principle is not clear.Manufacturing of Polishing WheelsFine Al 2O3 and some soft polishing materials, such as Fe2O3, Cr 2O3, etc., are mixed together with fills. Unsaturated resin is used to bond these powders, where a chemical reaction takes place between the res

25、in and the activator. Theperformance of polishing wheels depends on the properties of resin and the composition of the polishing wheel. In order to contain the fine chips, which are generated by micro-cutting, some cheap soluble salt can be fed into the coolant. On the surface of the polishing wheel

26、, the salt will leave uniform pores, which not only increase the capacity to contain chips and self-sharpening of the polishing wheel, but also improves the contact situation between polishing wheel and ceramic tiles.Experimental ProcedureTests were carried out in a special manual grinding machine f

27、or ceramic tiles. Two grinding wheels were fixed in the grinding disc that was equipped to the grinding machine. The diameter of grinding disc was 255 mm. The rotating speed of the grinding disc was 580 rpm. The grinding and polishing wheels are isosceles trapezoid with surface area 31.5 cm2 (the up

28、per edge: 2 cm, base edge: 5 cm,the flatness and edge of the ceramic tiles, at least one third of the tile must be under the grinding disc. During the grinding process, sufficient water was poured to both cool and wash the grinding wheels and the tiles. Four kinds of vitreous ceramic tiles were exam

29、ined, as shown in Table 1.Two different sizes of ceramic A, A400 (size: 400 400 5mm3T and A500(size: 500 500 5mm3T were tested to understand the effect of the tile size.Forceramic tile B or C, the size was 500 500 5mm3: The phase composition ofthetiles was determined by x-ray diffraction technique.

30、Surface reflection glossinessand surface roughness of the ceramic tiles and the wear of grinding wheels weremeasured.T he gr i n d i n g a n d po l i sh i n g w he el s w er e m ad e in - of t h e 3 # grinding wheels were tested. The ceramic tile was marked as A500-1 (or B500-1,C500-1, A400-1) witho

31、f fills and additives. Only in 4#B, a few Al 2O3, bariumsulfate, and magnesium stearate were added for of the polishing wheels 0#A and 0#B were different as well. In 0#B, a few white alundum (average diameter 1mm), barium sulfate, and chrome oxide were used as polishing additives, specially. After g

32、round by 4#A (or 4#B) grinding wheel, the ceramic tiles were polished with 0#A (or 0#B). The processing combinations with 4# grinding wheels and 0#Table 1. Properties of Ceramic TilesCeramicHV0.1CrystallineMulliteQuartzVitreousPorosityPoreTilesGrain Size(vol.%)(vol.%)Mass(vol.%)Size(mm)(vol.%)(mm)A4

33、00,A500661.010-3032-40 15-1835-403-55-20B500710.610-3032-4010-1335-405-73-50C500614.210-3012-1510-1335-403-55-30polishing wheels were marked as 4#A0#A, 4#A 0#B, 4#B 0#A, 4#B 0#B for eachceramic tile.RESULTS AND DISCUSSIONSEffects of 2# and 3# Grinding WheelsSurface QualityIn rough grinding with a 2#

34、 grinding wheel, the surface roughness for all the tiles asymptotically decreases as the grinding time increases, see Fig. 1. The initial asymptote point of this curve represents the optimized rough grinding time, as continued grinding essentially the surface roughness. In these tests, the surfacero

35、ughness curves decrease with grinding time and become smooth at,120 sec. Thefinal surface quality for different kinds of ceramic tiles is slightly different. Interms of the initial size of the tile, the surface roughness of ceramic tile A400 e 400 5mm3T is lower than that of A500 e500 500 5mm3T: The

36、surfaceroughness ofceramictileB500 rapidly drops as the grindingtimeincreases.Thus, it is easier to remove surface material from thethe 3# grinding wheel step,all craters and cracks on the surface of ceramic tiles caused by the 2# grinding wheel must be removed. If residual cracks and craters exist,

37、 it will be impossible to get a the next step. The surface roughness obtained by the 2# grinding wheel will also affect the surfaceFigure 1. Surface roughness of several ceramic tiles as a function of grinding time for 2# grindingwheel.quality of next grinding step by the 3# grinding wheel. In Fig.

38、2, the actions of the3# grinding wheels are given using the ceramic tiles with different initial Ra, which were ground by the 2# grinding wheel for 180 sec. The curves of surface vs. grinding time rapidly decrease in 60 sec. Asymptotic behavior essentially becomes constant after 60 sec. In general,

39、the larger the initial surface roughness, theworse the final surface roughness. For example, for ceramic tile B500-1, the initial Ra was 1.53mm, the finial R a was 0.59mm after being ground by the 3# grindingwheel. When the initial Rawas 2.06mm for ceramic tile B500-2, the finial Ra was0.67mm.InRef.

40、 8, we studied the relations between abrasive mesh size and evaluationindices of surface quality,such as surface roughness and surface glossiness.Inrough grinding, the ground surface of ceramic tile shows fracture craters. These craters scatter the light, so that the surface glossiness values are al

41、most constantat a low level. It is difficult to improve the surface glossiness after these steps. Figure 3 shows the slow increase in surface glossinesswith time by means of the 3# grinding wheel. It can be seen that the glossiness of ceramic tile B500-1 is the that of A500-1 because the effective g

42、rinding times per unit areafor former is longer than for latter. These trends are similar to those for surfaceroughnessinFig. 2.Wear of Grinding WheelsThe wear of grinding wheels is one of the factors controlling the machining cost. As shown in Fig. 4, the wear of grinding wheels is proportional to

43、grindingFigure 2. Surface roughness of several ceramic tiles as a function of grinding time for 3# grindingwheel.of grinding time for 2# andFigure 3. Surface glossiness of several ceramic tiles as a function of grinding time by 3# grindingwheel.time for both the grinding wheels and the three types o

44、f ceramic tiles. The wear rate of the 3# grinding wheel is larger than the 2# grinding wheel. It implies that the wear resistance of the 3# grinding wheel is not as good as 2# for constant grinding time of 180 sec. When the slope of the curve is smaller, life of thegrinding wheels will be longer. Co

45、mparison of the ceramic tilesFig. 4 does notreveal a strong dependency. Therefore, the3# grinding wheels.initial surface roughness of ceramic tile will affect the wear of grinding wheel. In Fig. 4, the wear of the 3# grinding wheel for ceramic tile B500-1 is smaller than that for ceramic tile B500-2

46、. The initial surface roughness of the latter is that of the former so that additional grinding time is required to remove the deeperresidual craters on the surface. Improvement of the initial surface roughness can be the principal method for obtaining better grinding quality and grinding wheellife

47、during rough grinding.Effects of 4# Grinding Wheels and 0# Polishing WheelsSurface QualityThe combination and the performance of 4# grinding and 0# polishing wheels show different results for each ceramic tile. The grinding quality vs. grinding (polishing) time curves are presented in Fig. 5, where

48、all the ceramic tiles were previously ground by 2# and 3# grinding wheels to the same surface quality.The surface glossinessis used to assesssurface quality because the surface roughness is nearly constant as finishing or polishing time increases8. In this test, the ceramic tile A400 were fast groun

49、d by 4#A and 4#B grinding wheels Fig. 5(a). The surface glossiness increased rapidly during the initial 90 sec and then slowly increased. The surface glossiness by grinding wheel 4#B is by 4#A. Afterwards, polishing was done by four different combinations of finishing wheel and polishing wheel. By m

50、eans of polishing wheels 0#A and 0#B, we processed the surface finished by 4#A grinding wheel (described as 4#A0#A and 4#A 0#B inF i g.5 ) ,a n dt h es u r f a c ef i n i sh edb y4 # Bg r i n d i n gw h e e l(described as 4#B0#A and 4#B 0#B in Fig. 5). The curves of surface glossiness vs. polishing

51、time show parabolic behavior. After 60 sec of polishing, the surfaceglossiness reaches to,508, then slowly increases. The polishing wheel 0#B gives abetter surface quality than 0#A.In Fig. 5(a), the maximum surface glossiness of ceramic tile A400 is about,75by 4#B0#B. The relation between initial su

52、rface glossiness and the final surface quality is not strong. The effect of pre-polishing surface glossiness can be observed by 0#B polishing wheel as polishing ceramic tile A500 Fig. 5(b). Themaximum surface glossiness that can be achieved is 748in 240 sec by 4#A0#B or4#B0#B. This value is lower th

53、an that of ceramic tile A400 Fig. 5(a).The final surface glossinessby 4#A grinding wheel is in Fig. 5(c), but the final polishing roughness is the same when 0#A polishing wheel is used. The better performance of 0#B polishing wheel is shown because the surface glossiness canincrease from 17 to 228 in 30 sec. The maximum surface glossiness is 658 by 4#B0#B. The curves of polishing time vs. surf