拋光瓷磚畢業(yè)設(shè)計(jì)外文文獻(xiàn)翻譯

1、<p>　　畢業(yè)設(shè)計(jì)外文資料翻譯</p><p>　　題 目 POLISHING OF CERAMIC TILES </p><p>　　拋光瓷磚 </p><p>　　學(xué) 院 材料科學(xué)與工程 </p><p>　　專

2、業(yè) 復(fù)合材料與工程 </p><p>　　班 級(jí) 復(fù)材0802 </p><p>　　學(xué) 生 竇文杰 </p><p>　　學(xué) 號(hào) 20080103114

3、 </p><p>　　指導(dǎo)教師 邵明梁 </p><p>　　二〇一二年三月二十八日</p><p>　　MATERIALS AND MANUFACTURING PROCESSES, 17(3), 401–413 (2002)</p><p>　　POLISHING

4、OF CERAMIC TILES</p><p>　　C. Y. Wang,* X. Wei, and H. Yuan</p><p>　　Institute of Manufacturing Technology, Guangdong University ofTechnology, Guangzhou 510090, P.R. China</p><p><

5、;b>　　ABSTRACT</b></p><p>　　Grinding and polishing are important steps in the production of decorative vitreous ceramic tiles. Different combinations of finishing wheels and polishing wheels are test

6、ed to optimize their selection. The results show that the surface glossiness depends not only on the surface quality before machining, but also on the characteristics of the ceramic tiles as well as the performance of gr

7、inding and polishing wheels. The performance of the polishing wheel is the key for a good final surface quali</p><p>　　Key Words: Ceramic tiles; Grinding wheel; Polishing wheel</p><p>　　INTRODUC

8、TION</p><p>　　Ceramic tiles are the common decoration material for floors and walls of</p><p>　　hotel, office, and family buildings. Nowadays, polished vitreous ceramic tiles are more popular as

9、 decoration material than general vitreous ceramic tiles as they can</p><p>　　*Corresponding author. E-mail: cywang@gdut.edu.cn</p><p><b>　　401</b></p><p>　　Copyright q

10、2002 by Marcel Dekker, Inc. www.dekker.com</p><p>　　have a beautiful gloss on different colors. Grinding and polishing of ceramic tiles</p><p>　　play an important role in the

11、 surface quality, cost, and productivity of ceramic tiles</p><p>　　manufactured for decoration. The grinding and polishing of ceramic tiles are</p><p>　　carried out in one pass through polishing

12、 production line with many different</p><p>　　grinding wheels or by multi passes on a polishing machine, where different</p><p>　　grinding wheels are used.</p><p>　　Most factories u

13、tilize the grinding methods similar to those used for stone</p><p>　　machining although the machining of stone is different from that of ceramic tiles.</p><p>　　Vitreous ceramic tiles are thin,

14、usually 5–8mm in thickness, and are a sintered</p><p>　　material,which possess high hardness, wear resistance, and brittleness. In general, the</p><p>　　sintering process causes surface deformat

15、ion in the tiles. In themachining process, the</p><p>　　ceramic tiles are unfixed and put on tables. These characteristics will cause easy</p><p>　　breakage and lower surface quality if grinding

16、 wheel or grinding parameters are</p><p>　　unsuitable. To meet the needs of ceramic tiles machining, the machinery, grinding</p><p>　　parameters (pressure, feed speed, etc.), and grinding wheels

17、 (type and mesh size of</p><p>　　abrasive, bond, structure of grinding wheel, etc.) must be optimized.</p><p>　　Previous works have been reported in the field of grinding ceramic and</p>

18、<p>　　stone[1 – 4]. Only a few reports have mentioned ceramic tile machining[5 – 8], where</p><p>　　the grinding mechanism of ceramic tiles by scratching and grinding was studied. It</p><p>

19、;　　was pointed out that the grinding mechanism of ceramic tiles is similar to that of</p><p>　　other brittle materials. For vitreous ceramic tiles, removing the plastic deformation</p><p>　　groo

20、ves, craters (pores), and cracks are of major concern, which depends on the</p><p>　　micro-structure of the ceramic tile, the choice of grinding wheel and processing</p><p>　　parameters, etc. Th

21、e residual cracks generated during sintering and rough grinding</p><p>　　processes, as well as thermal impact cracks caused by the transformation of quartz</p><p>　　crystalline phases are the ma

22、in reasons of tile breakage during processing. Surface</p><p>　　roughness Ra and glossiness are different measurements of the surface quality. It is</p><p>　　suggested that the surface roughness

23、 can be used to control the surface quality of</p><p>　　rough grinding and semi-finish grinding processes, and the surface glossiness to</p><p>　　assess the quality of finishing and polishing pr

24、ocesses. The characteristics of the</p><p>　　grinding wheels, abrasive mesh size for the different machining steps, machining</p><p>　　time, pressure, feed, and removing traces of grinding wheel

25、s will affect the</p><p>　　processing of ceramic tiles[9].</p><p>　　In this paper, based on the study of grinding mechanisms of ceramic tiles, the</p><p>　　manufacturing of grinding

26、 wheels is discussed. The actions and optimization of</p><p>　　grinding and polishing wheels for each step are studied in particular for manualpolishing</p><p><b>　　machines.</b><

27、/p><p>　　GRINDING AND POLISHING WHEELS FOR CERAMIC TILE</p><p><b>　　MACHINING</b></p><p>　　The machining of ceramic tiles is a volume-production process that uses</p>

28、<p>　　significant numbers of grinding wheels. The grinding and polishing wheels for</p><p>　　ceramic tile machining are different from those for metals or structural ceramics.</p><p>　　In

29、 this part, some results about grinding and polishing wheels are introduced for</p><p>　　better understanding of the processing of ceramic tiles.</p><p>　　Grinding and Polishing Wheels</p>

30、<p>　　Ceramic tiles machining in a manual-polishing machine can be divided into</p><p>　　four steps—each using different grinding wheels. Grinding wheels are marked as</p><p>　　2#, 3#, an

31、d 4# grinding wheels, and 0# polishing wheel; in practice, 2# and 3#</p><p>　　grinding wheels are used for flattening uneven surfaces. Basic requirements of</p><p>　　rough grinding wheels are lo

32、ng life, high removal rate, and lower price. For 2# and</p><p>　　3# grinding wheels, SiC abrasives with mesh #180 (#320) are bonded by</p><p>　　magnesium oxychloride cement (MOC) together with s

33、ome porous fills,</p><p>　　waterproof additive, etc. The MOC is used as a bond because of its low price,</p><p>　　simple manufacturing process, and proper performance.</p><p>　　The

34、4# grinding wheel will refine the surface to show the brightness of ceramic</p><p>　　tile. The GC#600 abrasives and some special polishingmaterials, etc., are bonded by</p><p>　　MOC. In order to

35、 increase the performance such as elasticity, etc., of the grinding</p><p>　　wheel, the bakelite is always added. The 4# grinding wheels must be able to rapidly</p><p>　　eliminate all cutting gr

36、ooves and increase the surface glossiness of the ceramic tiles.</p><p>　　The 0# polishing wheel is used for obtaining final surface glossiness, which</p><p>　　is made of fine Al2O3 abrasives and

37、 fill. It is bonded by unsaturated resin. The</p><p>　　polishing wheels must be able to increase surface glossiness quickly and make the</p><p>　　glossy ceramic tile surface permanent.</p>

38、<p>　　Manufacturing of Magnesium Oxychloride Cement Grinding Wheels</p><p>　　After the abrasives, the fills and the bond MOC are mixed and poured into the</p><p>　　models for grinding whe

39、els, where the chemical reaction of MOC will solidify the</p><p>　　shape of the grinding wheels. The reaction will stop after 30 days but the hardness of</p><p>　　grinding wheel is essentially c

40、onstant after 15 days. During the initial 15-day period,</p><p>　　the grinding wheels must be maintained at a suitable humidity and temperature.</p><p>　　For MOC grinding wheels, the structure o

41、f grinding wheel, the quality of</p><p>　　abrasives, and the composition of fill will affect their grinding ability. All the</p><p>　　factors related to the chemical reaction of MOC, such as the

42、 mole ratio of</p><p>　　MgO/MgCl2, the specific gravity of MgCl2, the temperature and humidity to care</p><p>　　the cement will also affect the performance of the MOC grinding wheels.</p>

43、<p>　　Mole Ratio of MgO/MgCl2</p><p>　　When MOC is used as the bond for the grinding wheels, hydration reaction</p><p>　　takes place between active MgO and MgCl2, which generates a hard<

44、;/p><p>　　XMgeOHT2·YeMgCl2T·ZH2O phase. Through proper control of the mole ratio of</p><p>　　MgO/MgCl2, a reaction product with stable performance is formed. The bond is</p><p&

45、gt;　　composed of 5MgeOHT2·eMgCl2T·8H2O and 3MgeOHT2·eMgCl2T·8H2O: As the</p><p>　　former is more stable, optimization of the mole ratio of MgO/MgCl2 to produce</p><p>　　more

46、5MgeOHT2·eMgCl2T·8H2O is required. In general, the ideal range for the</p><p>　　mole ratio of MgO/MgCl2 is 4–6. When the contents of the active MgO and</p><p>　　MgCl2 are known, the qu

47、antified MgO and MgCl2 can be calculated.</p><p>　　Active MgO</p><p>　　The content of active MgO must be controlled carefully so that hydration</p><p>　　reaction can be successfully

48、 completed with more 5MgeOHT2·eMgCl2T·8H2O: If</p><p>　　the content of active MgO is too high, the hydration reaction time will be too short</p><p>　　with a large reaction heat, which

49、increases too quickly. The concentrations of the</p><p>　　thermal stress can cause generation of cracks in the grinding wheel. On the</p><p>　　contrary, if the content of active MgO is too low,

50、the reaction does not go to</p><p>　　completion and the strength of the grinding wheel is decreased.</p><p>　　Fills and Additives</p><p>　　The fills and additives play an important

51、role in grinding wheels. Some porous fills must be added to 2# and 3# grinding wheels in order to improve the capacity to contain the grinding chips, and hold sufficient cutting grit. Waterproof additives such as sulfate

52、s can ensure the strength of grinding wheels in processing under water condition. Some fills are very effective in increasing the surface quality of ceramic tile, but the principle is not clear.</p><p>　　Ma

53、nufacturing of Polishing Wheels</p><p>　　Fine Al2O3 and some soft polishing materials, such as Fe2O3, Cr2O3, etc., are mixed together with fills. Unsaturated resin is used to bond these powders, where a che

54、mical reaction takes place between the resin and the hardener by means of an activator. The performance of polishing wheels depends on the properties of resin and the composition of the polishing wheel. In order to conta

55、in the fine chips, which are generated by micro-cutting, some cheap soluble salt can be fed into the coolant. On t</p><p>　　Experimental Procedure</p><p>　　Tests were carried out in a special ma

56、nual grinding machine for ceramic</p><p>　　tiles. Two grinding wheels were fixed in the grinding disc that was equipped to the</p><p>　　grinding machine. The diameter of grinding disc was 255 mm

57、. The rotating speed</p><p>　　of the grinding disc was 580 rpm. The grinding and polishing wheels are isosceles</p><p>　　trapezoid with surface area 31.5 cm2 (the upper edge: 2 cm, base edge: 5

58、cm,</p><p>　　height: 9 cm). The pressure was adjusted by means of the load on the handle for</p><p>　　different grinding procedures. A zigzag path was used as the moving trace for the</p>

59、<p>　　grinding disc. To maintain flatness and edge of the ceramic tiles, at least one third</p><p>　　of the tile must be under the grinding disc. During the grinding process, sufficient</p><

60、p>　　water was poured to both cool and wash the grinding wheels and the tiles.</p><p>　　Four kinds of vitreous ceramic tiles were examined, as shown in Table 1.</p><p>　　Two different sizes of

61、 ceramic A, A400 (size: 400 ￡ 400 ￡ 5mm3T and A500</p><p>　　(size: 500 ￡ 500 ￡ 5mm3T were tested to understand the effect of the tile size. For</p><p>　　ceramic tile B or C, the size was 500 ￡ 5

62、00 ￡ 5mm3: The phase composition of the</p><p>　　tiles was determined by x-ray diffraction technique. Surface reflection glossiness</p><p>　　and surface roughness of the ceramic tiles and the we

63、ar of grinding wheels were measured.</p><p>　　The grinding and polishing wheels were made in-house. The 2# grinding</p><p>　　wheels with abrasives of mesh #150 and 3# grinding wheels with mesh #

64、320 were</p><p>　　used during rough grinding. Using the ceramic tiles with different surface</p><p>　　toughness ground by the 2# grinding wheel for 180 sec, the action of the 3#</p><p

65、>　　grinding wheels were tested. The ceramic tile was marked as A500-1 (or B500-1,</p><p>　　C500-1, A400-1) with higher initial surface toughness or A500-2 (or B500-2,</p><p>　　C500-2, A400-2)

66、 with lower initial surface toughness.</p><p>　　Two kinds of finishing wheels, 4#A and 4#B were made with the same structure, abrasivity, and process, but different composition of fills and additives. Only i

67、n 4#B, a few Al2O3, barium sulfate, and magnesium stearate were added for higher surface glossiness. The composition of the polishing wheels 0#A and 0#B were different as well. In 0#B, a few white alundum (average diamet

68、er 1mm),</p><p>　　barium sulfate, and chrome oxide were used as polishing additives, specially. After ground by 4#A (or 4#B) grinding wheel, the ceramic tiles were polished with 0#A (or 0#B). The processing

69、combinations with 4# grinding wheels and 0#</p><p>　　Table 1. Properties of Ceramic Tiles</p><p>　　polishing wheels were marked as 4#A–0#A, 4#A–0#B, 4#B–0#A, 4#B–0#B for each ceramic tile.</p

70、><p>　　RESULTS AND DISCUSSIONS</p><p>　　Effects of 2# and 3# Grinding Wheels</p><p>　　Surface Quality</p><p>　　In rough grinding with a 2# grinding wheel, the surface roug

71、hness 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 has n

72、o effect on the surface roughness. In these tests, the surface roughness curves decrease with grinding time and become smooth at ,120 sec. The final surface quality for different kinds of ceramic tiles is slightly differ

73、</p><p>　　Thus, it is easier to remove surface material from the hardest of the</p><p>　　three kinds of the ceramic tiles (Table 1). However, as the final surface roughness of ceramic tile A500

74、is the same as that of ceramic tile C500, the hardness of theceramic tile does not have a direct relationship with the final surface quality.</p><p>　　In the 3# grinding wheel step, all craters and cracks on

75、 the surface of ceramic tiles caused by the 2# grinding wheel must be removed. If residual cracks and craters exist, it will be impossible to get a high surface quality in the next step. The surface roughness obtained by

76、 the 2# grinding wheel will also affect the surface</p><p>　　Figure 1. Surface roughness of several ceramic tiles as a function of grinding time for 2# grinding</p><p><b>　　wheel.</b>

77、;</p><p>　　quality of next grinding step by the 3# grinding wheel. In Fig. 2, the actions of the 3# grinding wheels are given using the ceramic tiles with different initial Ra, which were ground by the 2# gr

78、inding 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, the larger the initial surface roughness, the worse

79、 the final surface roughness. For example, for ceramic tile B500-1, the initial Ra w</p><p>　　In Ref. [8], we studied the relations between abrasive mesh size and evaluation indices of surface quality, such

80、as surface roughness and surface glossiness. In rough grinding, the ground surface of ceramic tile shows fracture craters. These craters scatter the light, so that the surface glossiness values are almost constant at a l

81、ow level. It is difficult to improve the surface glossiness after</p><p>　　these steps. Figure 3 shows the slow increase in surface glossiness with time by means of the 3# grinding wheel. It can be seen that

82、 the glossiness of ceramic tile B500-1 is the highest. The surface glossiness of ceramic tile A400-1 is better than that of A500-1 because the effective grinding times per unit area for former is longer than for latter.

83、These trends are similar to those for surface roughness in</p><p><b>　　Fig. 2.</b></p><p>　　Wear of Grinding Wheels</p><p>　　The wear of grinding wheels is one of the fa

84、ctors controlling the machining cost. As shown in Fig. 4, the wear of grinding wheels is proportional to grinding</p><p>　　Figure 2. Surface roughness of several ceramic tiles as a function of grinding time

85、for 3# grinding</p><p><b>　　wheel.</b></p><p>　　Figure 3. Surface glossiness of several ceramic tiles as a function of grinding time by 3# grinding</p><p><b>　　whe

86、el.</b></p><p>　　time for both the grinding wheels and the three types of ceramic tiles. The wear rate of the 3# grinding wheel is larger than the 2# grinding wheel. It implies that the wear resistance

87、 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 the</p><p>　　grinding wheels will be longer. Comparison of the ceramic ti

88、les hardness (Table 1) with the wear resistance behavior in Fig. 4 does not reveal a strong dependency. Therefore, the hardness of the ceramic tile cannot be used to distinguish the machinability. The difference of</p

89、><p>　　Figure 4. Wear of grinding wheels of several ceramic tiles as a function of grinding time for 2# and</p><p>　　3# grinding wheels.</p><p>　　initial surface roughness of ceramic t

90、ile 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. The initial surface roughness of the latter is higher than th

91、at of the former so that additional grinding time is required to remove the deeper residual craters on the surface. Improvement of the initial surface roughness can be the principal method for obtaining better grinding q

92、uality and grinding wh</p><p>　　Effects of 4# Grinding Wheels and 0# Polishing Wheels</p><p>　　Surface Quality</p><p>　　The combination and the performance of 4# grinding and 0# pol

93、ishing</p><p>　　wheels show different results for each ceramic tile. The grinding quality vs. grinding (polishing) time curves are presented in Fig. 5, where all the ceramic tiles were previously ground by 2

94、# and 3# grinding wheels to the same surface quality.</p><p>　　The surface glossiness is used to assess surface quality because the surface roughness is nearly constant as finishing or polishing time increas

95、es[8]. In this test, the ceramic tile A400 were fast ground 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

96、 by grinding wheel 4#B is higher than by 4#A. Afterwards, polishing was done by four different combinations of finishing wheel and polis</p><p>　　(described as 4#B–0#A and 4#B–0#B in Fig. 5). The curves of s

97、urface glossiness vs. polishing time show parabolic behavior. After 60 sec of polishing, the surface glossiness reaches to ,508, then slowly increases. The polishing wheel 0#B gives a better surface quality than 0#A.<

98、/p><p>　　In Fig. 5(a), the maximum surface glossiness of ceramic tile A400 is about ,75 by 4#B–0#B. The relation between initial surface glossiness and the final surface quality is not strong. The effect of pre

99、-polishing surface glossiness can be observed by 0#B polishing wheel as polishing ceramic tile A500 [Fig. 5(b)]. The maximum surface glossiness that can be achieved is 748 in 240 sec by 4#A–0#B or 4#B–0#B. This value is

100、lower than that of ceramic tile A400 [Fig. 5(a)].</p><p>　　The final surface glossiness by 4#A grinding wheel is highly different from that by 4#B grinding wheel for ceramic tile B500, as shown in Fig. 5(c),

101、 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 can</p><p>　　increase from 17 to 228 in

102、30 sec. The maximum surface glossiness is 658 by 4#B– 0#B. The curves of polishing time vs. surface glossiness in Fig. 5(d) present the same results as polishing of ceramic tile B500 [Fig. 5(c)]. With 0#A polishing</p

103、><p>　　Figure 5. Surface glossiness for ceramic tiles (a) A400, (b) A500, (c) B500, and (d) C500 as a</p><p>　　function of grinding (polishing) time for 4# grinding wheels and 0# polishing wheels.&

104、lt;/p><p>　　wheel, the action of pre-polishing surface glossiness is significant. The best value of surface glossiness in 240 sec is 708 by 4#B–0#B as polishing ceramic tile C500. The results discussed earlier

105、describe that the surface glossiness by 0# polishing wheel will depend not only on the pre-polishing surface glossiness formed by 4# grinding wheel, but also on the characteristics of the ceramic tiles and the performanc