2010) 3( 23المجلد مجلة ابن الھیثم للعلوم الصرفة والتطبیقیة دراسة الخواص الفیزیائیة والتشكیلیة للعازل السیرامیكي عتاب فاضل حسین الجامعة المستنصریة ،كلیة العلوم ،قسم الفیزیاء الخالصة وبنسب وزنیة )سلیكا،فلدسبار،كاؤلین(عراقیة ةمواد محلی عمالبحث تحضیر عازل سیرامیكي باستتم في هذا ال ،و على التوالي وبعد اجراء عملیة التنقیة،(30% ,25%,45%) ة بلتجفیف،والطحن لالطیان العراقیة او الغسل صورة انفرادی تكبس .من الماده المعدنة ةثابت ةوبنسی(%0.1,%0.2,%0.5,%0.7,%1)نسب مختلفة من سلیكات الصودیوم أضیفت (1350 ,1250) ةبدرجات حراری تقى شكل اقراص وحرّ النماذج عل o C ة . على التوالي استخدام المجهر الضوئي لدراس أوضحت .باستخدام طریقة آرخمیدس كافة لنماذجلسطوح النماذج ثم اجریت قیاسات الكثافة الظاهریه والمسامیة الظاهریة لیة مع ارتفاع درجة الحرق نتیجة ي الحاصل بین المواد االو ئاذج ارتفاع نسبة التفاعل الكیمیاالصور المجهریة لسطوح النم ةالنصهار الحاصل الذي یعمل على زیادة التقارب الحبیبي على حساب المناطق عیر المتفاعلة والفجوات وان افضل نسبل .لسلیكات الصودیوم) %0.5(لفحوصات الكثافة والمسامیة الظاهریه هي عند تركیز .عازل السیرامیكي ، الكثافة ، المسامیة ال: الكلمات المفتاحیة IHJPAS IBN AL- HAITHAM J. FO R PURE & APPL. SC I. VO L.23 (3 ) 2010 Study o f the Physical and Morphological Properties of Ceramic Insulator I. F. Hussein Departme nt of Physics, College of Science ,Unversity of Al - Mustansiryah Abstract In this invest igation insulator ceramic body was p rep ared by using iraqi local materials, these are kaolin, silica sand glass, feldsp ar with weight p ercentage (45%,25%, 30%)resp ectively. After the end of treating dry ing and milling of raw material mixing with different concentrations of sodium silicate(1%,0.7%,0.5%,0.2%,0.1%) whi le zinc o xide was added at fixed weight p ercenta ge. A disc sa mples was p repared after comp action and then fired by sintering temp eratures (1250, 1350) o C resp ectively.A surface morphology was st udied by using optical microscop e and measurements of apparent density and porosity was under taken to the sintered samples by using Archimedes method.T he st udy showed that the microscopic images for samples surface showed that gr ains st art in convergence with other and gr ain size increasing with firin g temp erature and the best result of apperant density and p orosity at 0.5% concentration of sodium silicate . Key words: ceramic insulator, density , p orosity. Introduction Ceramic material can be defined as “ in or ganic &non metallic materials that are artificially manufactured by high temp erature reaction” and sometimes heat and p ressure[1] . Ceramic materials have the followin g generalized materials p rop erties, low density , low in toughness, high moduli, very hard , very high melting p oints, wear - resistance, brittle, good thermal shock résistance, excellent electrical and thermal insulation, good relation of p rop erties at high temp eratures, and chemically st able[2]. The field of cer amic science could be broadly classified as traditional and advan ced ceramic. Traditional cer amic are those mad e fro m naturally occurring materials like clays and minerals without required much refin ement characterized by mostly silicate - base p orous microstructure that are quite coarse, non uniform and multip hase[3]Advanced ceramic are develop ed by chemical sy nthesis, there are man - mad e and can be made fro m high refined naturally occurring materials. The microstructures of these advanced cer amics were at least an order of magnitude finer and more homogenous and much less p orous t han those of their traditional counterp art [2]. Some material like zinc o xide used to imp rove the chemical dur ability of some comp osition , zinc oxide is p roduced by direct o xidation of zinc metal and it uses a mineralized[4,5]. Sodium silicate solution has som e char acterist ic p hy sical p rop erties which make them suitable for certain industries p urp ose. It appears that solution p referentially wets supp ly of sodium silicates; cer amic is decorated with glaze in comp osition of which the silicate solution serves the double p urp ose supp lying its share of sodium o xide and silica, and of keeping the other ingr edients in p osition till the sintering temp erature [6] sodium silicate are used as defloccu lated in the processing of raw clay and other mineral slurries. Silicates reduce slurry viscosities making them easier to p ump and process. This help s in the removal of imp urities and provides saving in ener gy costs. Sodium silicate is also used in clay slip cast ing lower IHJPAS IBN AL- HAITHAM J. FO R PURE & APPL. SC I. VO L.23 (3 ) 2010 viscosities imp rove cast ing time because less water is need ed, firing times are r educes and final product is stronger and exhibits less shrinkage and low p orosity [7]. Experime ntal procedure - Raw material treatment:- Kaolin and silica sand glass treated by washing them with HCl for time duration hour at room temp erature. The washed materials sep arated using filter p apers under sequence of op eration for dilution and filtering until PH - valu e become 5. Then the sep arated material milled usin g b all mill of p orcelain body for 7 hours and si eved to obtain p owder with p article size about 75 μm. - S ample preparation: - The raw materials used for the p reparation are k aolin, silica sand glass,and feldsp ar with p ercentage (45%, 25%, 30%) resp ectively. 2%of zinc o xide was added to the mixture followin g by mixing for 2 hours. The final mixture then divided into five group s related to concentration of sodium silicate (1%, 0.7%, 0.5%, 0.2%, and 0.1%). PVA binder was p rep ared and app lied with 1%wt for each group . The mixture p rocess was carried und er heating 80 o C until get a slurry form, and then dried at 60 o C with continuous mixing for four hours unt il obtain agglomerated p owder. - Si ntering process:- The final p owder was milled for 2 hour and sieved to size of 250 μm. These samp les were dried after p ressed with p ressure of 8M Pa as disc form, the p repared samples sintered using different temp eratures(1250, 1350) o C with sinter time hours. - Optical microscope tests:- The op tical microscopy was p rovided with digital camer a and comp uter sy stem (model Nikon M E600, attached with digital camer a DXM /200F).This sy stem is used for p hotographing the samp les, before photographing, the surface of samples must be grinded. - Measurement of apparent density and apparent porosity. App arent density and porosity of sintered samples were determined by using Archimedes M ethod [8].According to ASTM C20-18T,(American Standard Test M ethods)[9],which cover the determination of the followin g p rop erties of sintered samp les. 1 -Dry weight (wd): Samp les dried or sintered by heating them for 2 hour at 100 o c, to insure that residual moist ure must be removed, and determined the dry weight (wd) for t he samp les. 2 -Saturation: Place the samples in a beaker of distilled water and boil it for 2 hour. During the boiling p eriod , k eep them entirely covered with water, allow no contact with the heated botton of the container , keep the samples immerse in water for 12-24 hours before weighting . 3 -Susp ended weight Wsu: This weighting is accomplished by connectin g a copp er wire end at the downside of the balance and the other end of the terminals of the meshwork immersed in distilled water, the balance should be previously counter-blace. Place the saturated samples on the susp ending meshwork for determin ing the susp ended weight Wsu . 4 -Saturated weight Wsa: Aft er determining the susp ended weight, blot the sample lightly with moist ened smooth linen or cott on cloth to remove all drop s of water from the surface and determine the saturated weight (Wsa). Excessive blott ing or (p ressing) will induce error by withdrawing water from the pores of the samp le. 5 -Bulk density (ρB ) The bulk density (ρB )or app erant density of the sample is determined by using rhe followin g equation IHJPAS IBN AL- HAITHAM J. FO R PURE & APPL. SC I. VO L.23 (3 ) 2010 water SUd d B WW W lumeapperantvo Dryweigh     Where the volume of the liquid d isp lace, which is id entical to t he volume of the samp le. 6 - App arent p orosity The app arent p orosity exp resses as p ercentage by using the exp ression App arent p orosity%= %100 etotalvolum lumeopenporevo App arent p orosity%= 100   suwsaw d wsaw Result and Discussion Figures 1 and 2 revel the surface morphology of sample taken by the op tical microscope; it is known that ceramic color is typ ically gr ay, brownish or color less with vitreous luster. Figure(1)shows the image taken to samples fired at 1250 o C for 2 hours have different surface st ructure and color than sample firing at 1350 o C in f igure (2). The images show in f ig.(1) include t he existence of white sp ot beside a small amount of gr ay region through a flux whi ch refers to uncomp leted melting of st ating materials and the r eduction amount of energy required to follow comp lete reaction between the composition with resp ect of time of firing. For samples firin g 1350 o C the image exp lain white and brown agglomerate which indicate p resent more than one phase and increase of the rate of reaction between melted material in comp osition firing at 1350 o C and decrease in p rose esp ecially when at sample (d1) which contains a concentration of sodium silicate as t able (1). Physical char acterist ic p arameters (App arent density and app arent p orosity): App arent density and p orosity were calculated from the data, that measured by using Archimed method from sa mples fired at temp erature 1250 o C, 1350 o C.The results of these group s are listed in table (1). Fig (2) shows the images taken to samples surface that are fired at 1350 o C, the melt rate for the material in comp osition increases the chemical reaction and p hase transformation to the major cryst alline phase cordierite. It is well known t hat t he powder density is an indirect measure of the degree of the firin g reaction comp ound formation that takes p lace when a powder mixture is reacted during firing. It is related to the amount of p article growt h [10]. Fi gures (3, 4) illust rate the behaviors of density and p orosity for samples with resp ect to firing temp eratures (1250, 1350) o C. Conclusion In conclusion , this p aper describes the possibility of manufacturing a good cer amic body from local material and obtain agood p rop erties (density &p orosity)by adding 0.5% concentration of sodium silicate. Re ference 1.Choudhary, S.K.H.(1985), material scien ce and processes“ndian book,distributing co. 2. M ichel, W.B. (1997), fundamentals of cermics” international edition,the M C Graw - Hill comp anies, Inc.newy ork. 3. Romasesho S. (1999), sience and technology of ceramic,p art 1, resonance , 4(8) ,p art 2, resonance,decemb er 4.Singer,F.and Sign er,S. S. (1963) industrial ceramic”chapman and hall Ltd,London. IHJPAS IBN AL- HAITHAM J. FO R PURE & APPL. SC I. VO L.23 (3 ) 2010 5.Toy lor,J.R.and Bull,A.C. (1986) Ceramic glaze technolo gy ,by p ergamon p ress, newy ork,. 6.Seli gman and Williams.J. (1977) , Low densily ceramics p roduced from p aper recy clirg residuals ,inst.M etals,28,297, 51-58 . 7.Forge,V. ( 2004), Advancein g the art of silicate ch emistry p .9, by PQ corp oration 8.Blythe, A.R. (1982) Advance in physics31(5): 24-28. 9. Gray , A.G. (1972) introduction to material scien ce M c.Graw - Hill 10. She, J.H., J. (2002) Prep aration of p orous cordierte ceramic usin g Silica Second ary resource (Silican fumrs )fordust filtration p urp oses,M ater.sci., 37,125-131 Table (1):Apparent density (g/cm 3 ) and apparent porosity for these groups at different firing temperature S amples Concentration of sodium silicate Apparent densi ty Apparent porosi ty 1250 o C 1350 o C 1250 o C 1350 o C A zero 1.179 1.339 9.3 0. 35 B 1% 1.194 1.51 11.6 0. 341 C 0.7% 1.205 1.398 13.9 0. 312 D 0.5% 1.462 1.37 17.1 0. 3 E 0.2% 1.6 1.63 13.8 1.1 F 0.1% 1.2 1.50 10.2 0. 7 IHJPAS IBN AL- HAITHAM J. FO R PURE & APPL. SC I. VO L.23 (3 ) 2010 A B D C F E Fig. (1) Optical microscopic image for samples firing at 1250 o C with concentrations of sodium silicate show in table (1) IHJPAS IBN AL- HAITHAM J. FO R PURE & APPL. SC I. VO L.23 (3 ) 2010 A1 B1 C1 D1 E1 F1 Fig.(2) Optical microscopic image for samples firing at 1350 o C with concentrations of sodium silicate show in table (1) IHJPAS IBN AL- HAITHAM J. FO R PURE & APPL. SC I. VO L.23 (3 ) 2010 0 0.002 0.004 0.006 0.008 0.01 0.012 0 0.005 0.01 0.015 Soduim silicate% P o ro s it y % 1.35 1.4 1.45 1.5 1.55 1.6 1.65 D e n s it y ( g /c m 3 ) 0 0.05 0.1 0.15 0.2 0 0.005 0.01 0.015 Soduim si lica te % P o ro s it y % 0 0.5 1 1.5 2 D e n s it y (g /c m 3 ) Fig.(3) The apparent density and porosity with concentration of sodium silicate for samples firing at 1350 o C Fig.(4) The apparent density and porosity with concentration of sodium silicate for samples firing at 1250 o C ▲ Density ● Porosity ▲ Density ● Porosity IHJPAS IHJPAS