2010) 1( 23مجلة ابن الھیثم للعلوم الصرفة والتطبیقیة المجلد المشكل من مواد محلیة يالبورسلین خصائص التقلص لجسم العازل السیرامیكي و رنا إسماعیل خلیل محاسن فاضل هادي حسین،عتاب فاضل الجامعة المستنصریة ، كلیة العلوم ،قسم الفیزیاء الخالصة لمحلــول اتــأثیر تغیــر نســب تركیــز خصــائص الــتقلص لجســم العــازل الســیرامیكي ،و الــى دراســة هــذا البحــث یهــدف كـاؤلین -:هـذه المـواد هـي .محلیـة ةمـواد عراقیـ المعحضـر بأسـت كهربـائيالعـازل جسـم ال. هذه الخصـائصفي اإللكترولیتي تصــنیف ، ال تمــت عملیــات. علــى التــوالي%) 25 و %30، % 45( ةدویخلــه،رمل زجــاج أرضــمه، فلدســبار وبنســب وزنیــ ة التـي تضـاف بتراكیــز مختلفـة للمحلــول یــعملیــة خلـط المحلـول االلكترولیتــي والمـادة المعدن لحــرق خـالالتشـكیل و والخلـط، وال المحلـول االلكترولیتـي حضـر بخلــط كاربونـات الصـودیوم وســلیكات . )%0.1 , %0.2 %0.7%0.5, (%1 ,االلكترولیتـي .د الزنك ، تضاف بنسبة وزنیة ثابتةی،أوكسة یند، بینما المادة المع) 1/2(دیوم بنسبةالصو ) 1250،1300،1350( لبدت بدرجات حرارة تلبیدت لنماذج مستطیلة ذالقیاسات أخ ە انـه حصلنا علیهـا النتیجة التي .م ) 1300،1350(اعلى تقلص كلي في ) %0.5( كترولیتيلمحلول االالتركیز ل ە وبـذلك فـان . ق كذلك علـى اعلـى تقلـص حـر و م .هربائيهذا التركیز هو االفضل العطاء المادة صفة العزل الك IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L. 23 (1) 2010 Shrinkage P roperties of Insulator Ceramic Body Porcelain Formed Using Lo cal Material It. F. Hussain , M. F. Hadi, R. I. Khaleel Departme nt of Physics, College of Science , Unive rsity of Al- Mustansiriyah Abstract This work was carried out to investigate the shrinkage prop erties of insulator ceramic body , and the effect of changing the ratio of con centration of electroly te solution on these p rop erties. The electrical insulator body was p repared by using Iraqi local materials. These are :- kaolin Duakh la, Arudhuma Sand glass, and potash feldsp ar with weight p ercentage (45%, 25%,and 30%) resp ectively. The p rocesses of milling, classification, mi xing, forming and firin g, through the process of mixing electroly te solution and mineralizer were added at different concentrations for electrolyte solution, (1%, 0.7%, 0.5%, 0.2%, and 0.1%). The electrolyte solution was p rep ared by mixing sodium carbonate and sodium silicate by (2:1) ratio, while the miner alize, Zinc O xide, was add ed at fixed weight p ercentage. The measurements were undertaken on rectangu lar sample burnt at sintering temp eratures of (1250, 1300,and 1350) o C. The result was obt ained at (0.5%) electrolyte solution concentration has hi ghest total shrinkage at (1300,1350) o C sinterin g temp erature and also high est firing shrink age .So that, it is the best concentration to get material prop erty of insulating. Introduction The st ructure and p rop erties of cryst alline ceramic material can be interp reted in terms of t heir comp lex st ructures and p hase diagram because of their britt le behavior, they are normally manufactured into useful comp onent by p ressing moist aggregated or p owders into shap es. Following by dry ing and firing. This p ermits the particles to shrinkage and sintering to become solid, the cryst alline ceramics ty p ically have high melting temp eratures, high hardness and are suitable for many high - temp erature or corrosion – resistant app lications [1,2]. Kaolin has numerous industrial app lications and new uses continued to be discovered. They are unique industrial app lications and new uses including chemical inertness over a wide range of acid/alkaline conditions [3]. It has been shown that cracking resulting from shrinkage p rocesses occurs esp ecially if the material is homogenized and close to its saturation p oint[4]. The shrinkage p rocess has been divided into normal shrinkage p hase and residual shrinking p hase[5]. Horn et al [6] showed normal shrinkage p rop erties while comp action at water contents below the op timum resulted in residual shrinkage behavior. Bauer et al [7] and Wysocka et al [8] found that the shrinkage p otential for Kaolin increased with water content during comp action. S hrinkage processes The major mechanical p rop erties for ceramic insulator are the shrinkage p rocesses. Shrinkage and dry ing are of p rofound concern to the st ructure clay p roducts industry . Since clay minerals are resp onsible for shrinkage, the amounts p ercentage and their p article sizes determine the shrinkage p otential, then the amount of water p resent in the p last ic clay is p rop ortional to, but not equal to shrinkage [2]. IBN AL- HAITHAM J. FOR PURE & APPL. SC I VO L. 23 (1) 2010 The values of liner firing shrinkage in the p ercent of shrinkage are due to variation in the size and shape of sample p article , the liner shrinkage is app roximately p rop ortional to the inverse of p artial radius but is not greatly affected sintering time [9,10]. Electrolyte sol uti on Electrolytes are class of solid solutions that exhibit sp ecial behavior comp ared to non– electrolytes. The distinction arises both because electrolytes dissociate up on dissolution and because the ions p roduced interact through much large distances than uncharged solutions [11]. It is well known that many substances– inorganic salts in p articular–dissociate to form ions in aqueous solutions. The most direct evidence of this is the large electrical conductivity of such solution; in fact, the solution is called electrolytes because it conduct electricity readily [12]. The electrical double lay er is formed at interfaces of charged objects and electrolyte solutions comp osed of ions and solvent molecules [13]. The ions with the charge of the op p osite sign than the charged object (counterions) are accumulated close to the charged object, while the ions with the charge of the same sign as the charged object (coions) are depleted from the vicinity of the charged object. Well known examp les of p lanar electrical double lay er are biological membranes, liquid cryst als and metals in contact with the electrolyte solution [2,14] . Clay minerals have the p rop erty of sort ing certain anions and cations, retaining these in an exchangeable st ate; i.e. they are exchangeable for other anions or cations by treatment with such ions in a water solution (the exchange reaction also t akes p lace sometimes in a non -aqueous environment). The exchangeable ions are held around the outside of silica–alumina clay mineral st ructural units, and the exchange reaction generally does not affect the st ructure of silica–alumina clay p acket. In clay minerals ,the common exchangeable cations are calcium, magnesium, hy drogen, p otassium, and sodium, frequently in about that order of general relative abundance [15]. The aim of the work One of additives, which are used in the p roduce of Porcelain bodies, is the electrolyte solution. Our st udy was carried out to op timize the required weight p ercentage of these additives t o be app licable to Porcelain body , which is p repared from Iraqi local material, to be used as an insulator ceramic body from the st udy of the shrinkage prop erties. S amples preparation Samp les were p repared with affixed p ercentage of raw material. 2%wt of Zinc oxide was added to the mixture followed by mixing for 2hours. A p olyvinyl alcohol binder was p repared and app lied with 1%wt for each group . The mixing p rocess was done under heating (80 o C) until it gets a slurry form, and then dried at 70 o C with continuous mixing for 3 hours, until obtaining agglomerated p owders. Electrolyte sol uti on preparation Electrolyte solution is p repared by using Na2CO3 & Na2SiO3 by ratio 2: 1 resp ectively. From this mixture, we determine the amount of adding distilled water to obtain electrolyte solution with concentration 5 %. So the amount of distilled water added was 114 ml. M ixing 4 gram of Na2CO3 with 2gm of Na2SiO3 and solving these massed in 50 ml distilled water, with continues mixing p rocess for half hour using magnetic st irrer (model (Great Britain, serial 11750)). Aft er that we carried on adding distilled water to obtain a final volume 114 ml. The p reparation of electrolyte solutions with the concentrations (1%, 0.7 %, 0.5 %, 0.2 %, and 0.1 %) from mentioned above 5 % done by using dilution equation given by [16]:- M i Vi = Mj VJ ---------- (1) IBN AL- HAITHAM J . FO R PURE & APPL. SC I VO L. 23 (1) 2010 Where M i is the p ercentage of solution before dilution, Vi is the volume of solution before dilution, M j is the p ercentage of solution after dilution, Vj is the volume of solution after dilution. S inte ring Processe s The final p owder was milled for about one hour, and then sieved by using a sieve of size 250 μm. The sieved p owders then were p ressed by using p ress (model (38888.4D10A00, made in USA)), with p ressure 7M Pa for 5 min., a rectangular form of length 50mm. These samples were dried in a furnace at a temp erature 70 o C for two hours. The p repared samples were burnt by a furnace ( model (Hi 62, Ti7, 1700, Nabertherm)) by using different temp eratures 1250, 1300, and 1350 o C, with sintering time 2 hr. and sintering rate 100 o C/ hr. Shrinkage test: The dry ing shrinkage, firing shrinkage and the total shrinkage were calculated for each test sp ecimen by using the following formula stated in [17,18]:- %100%    OL DLOL geingShrinkaAverageDry ...........(2) %100%    DL FLDL geingShrinkaAverageFir ...........(3) %100%    OL FLOL kageTotalShrin ......................(4) Where OL means Original Length, DL st ands for Dry Length and FL is Fired Length. Result and Discussion The results obt ained for the shrinkage tests are presented in table 1. The relation between dry ing shrinkage and concentration of electrolyte solution at different sintering temp eratures (1250, 1300, and 1350) o C was shown in fig{3}. It shows that t he behavior of curves at (1250 and 1300) o C is nearly similar. It reaches the maximum dry ing shrinkage at 0.2% concentration of electrolyte solution. While at 1350 o C the dry ing shrinkage reaches maximum at 0.5%. The large dry ing shrinkage indicates to some degree the p last icity of the mixture. So, the highest dry ing shrinkage led to absorb much water which in turn indicates fine mixture p articles. This is in agreement with the work of B.I.Ugheoke et al [3]. The relation between firing shrinkage and concentration of electrolyte solution is shown in fig. {4}. At (1250 and 1300) o C, the firing shrinkage reaches maximum at 0.5% concentration. While 0.2% concentration of electrolyte solution represents maximum firing shrinkage at 1350 o C. Fig. {5} and table 1, show that at 1350 o C the sample of 0.5% concentration of electrolyte solution has the highest total shrinkage 30.667. The least total shrinkage of 20.833 was for sample without electrolyte solution. At 1300 o C, the highest value of total shrinkage was 28 at 0.5% concentration of electrolyte solution. While, at 1250 o C, the value of total shrinkage is changeable from lowest to highest at 0.01% concentration of electrolyte solution. The firing shrinkage indicates how fusible the mixture is. A high shrinkage normally means a lower melting p oint. The tot al shrinkage of refractory bodies tells us how much bigger we should make our moulds. From our st udy there is an agreement that temp erature increases lead to higher shrinking of p ores, which subsequently leads to disapp earing of the many p ores, the result of this is that less water is absorbed by moulds[8,18]. The behavior clearly shows that there is a highly variation and non– linear p henomena. This can be exp lained, because each group have the same p ercentage of the raw material (kaolin Duekhla, Arut hma Sand Glass and feldsp ar) imp ling to the ability of the results depending on the mechanism of reaction between SiO2 – Na2O, as shown in figures IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L. 23 (1) 2010 {1} and, {2}. From all of the results, we can say that the highly p orous structure of samp le would make them suitable for b ack up insulation since the air whi ch fills the pores acts as an insulator. Conclusion Based on the shrinkage p rop erties of t he samp les tasted and analysed in this study , it can be conclud ed that the Porcelain which was p reformed from local material is suitable for the p roduction of insulating materials. From the result, that the samp les with 0.5% electrolyte solution have the best result at 1300, and 1350 o C that have high total shrinkage. Re ferences 1.Ewsuk,K. G. (1999)"Ceramic p rocessing",Entry for Ency clop ed of chemical p hy sics and p hy sical chemistry , ,version 9;13-99. 2.Askeland,D.R. (1988)"The science and engineering of materials", Van nost rand reinhold international co. Ltd, Hong Kon g. 3.Ugheoke,B.I. ; Onche, E.O.; Namessau, O.N. and Asikpo, G.A. (2006)"Prop erty optimization of Kaolin-Rice Husk insulating Fire- Briks", Leonardo Electronic Journa l of Practices and Technologies, ISSUE 9, July-December, P.167-178. 4.Hartge, K.H. and. Horn, R. E.(1999)In fuchrung in die Boden phy sik, 3 rd edition, Stuttgart,. 5.Junkersfeld ,L. and . Horn, R.(1997)"Variab ility of fixed water content on the example of soil aggregates", Z .Planzen Bodenk., 159:137-142. 6.Horn, R. and Stepniewski, W. (2004)" M odification of mineral liner to improve its long term st ability ", Int. Agrop hysics, 18 : 317-323. 7.Bauer, B. and Taubner, H. and Tip p koetter,R. (2001)"M easurement of mechanical and hy draulic comp ression susceptibility of clay subst rates with an improved p roctor test", Wasserund Boden, , 53:27-30. 8.Wysocka,A. and Stephiewski,W. and Horn,R. (2006)"Shrinkage prop erties of three clay materials at differ ent t emp eratures", Int. Agrop hysics, , 20:255-260. 9.Petrzzelli,G. and Guldi,G. and Sequi,P. (1976)"Electro-Optical measurement of clay shrinkage", Clay minerals, , 11:81-84. 10. Norsker, H. (1987)"The self reliant p otter: refractories and kilns", Vieweg& Sohn. 11. M cDonald ,J. A and . Rennie, A.R. (1995)Progress in colloid and p olymer science, , 98:75-78. 12.Berry, R.S. and Flynn, G.P. (1995)"Phy sical chemist ry" by John Wiely &Sons, Inc. New York. 13.Bohinc,K. (2003)"Effect of ion size in planar, cy lindrical and sp herical electrical double lay ers", , 10(4):167-171. 14.M claughlin, S. (1989)"The electrost atic prop erties of membranes, Ann. Rev. Biop hy s. Chem, , 18:113. 15.Grim,R. (1962)"App lied clay mineralo gy "M cGraw-Hill book comp any, Inc. NewYork and lLondon. 16.Skoo g, D.A. and West, D.M . (1986) "Analytical chemist ry and introduction", , 4 th edition, by CBS college publishin g, Chicago. 17.Chesters, J.H. (1973)"Refractories: Production and prop erties,Iron and Steel inst itut e", , London, P.P.24-25. 18. Onche, E.O. and Ugh eoke,B.I.and Lawl, S.A. and Dickson,U.M . (2007)"Effect of rice husk and diatomite on the insulating p rop erties of Kaolin-Clay firebriks", IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L. 23 (1) 2010 Fig. (2): The phase rel ationshi ps between S odium Disi licate and Corundum[19]. Leonardo Electronic Journa l of Practices and Technologies I SSUE 11, July -December, P.P.81-90. 19- Grimshaw,R.W. (1971) "The Chemistry and Phy sical of Clays and Allied Ceramic M aterials"4 th by Rex, W. Grimshaw Fig.(1):The Sodium oxide / silica phase diagram.[19] IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L. 23 (1) 2010 1200 800 1800 1600 1400 1000 20 40 60 80 1470 Tridymit e + li quid Na 2 O.2SiO2 + liquid 867 Quartz + li quid Na2O.2SiO2+quart z N a 2 O 2 S iN a 2 O . 2 S iO 2 Na2O.Sio2 + 2N a2O.SiO 2 2N a2O.SiO 2 + li quid Na2O + liquid Na2O.SiO2 + liquid Cristobalite + liquid Liquid Na2O.2SiO2 + Na2O.SiO2 SiO2 Na2O T em p er at u re o C Al2O3 100 20 600 0 40 60 80 SODUM DISILICATE+ NEPHLIT E Na2O.2SiO2 Na2O.Al2O3.2SiO2 1000 1400 1800 2200 1600 2000 800 1200 2050 o C CORUNDUM + LIQUID 1475 o C CORUNDUM +CARNEGIET E 1254 o C CORUNDUM + NEPHELIT E CARNEGIEITE + LIQUID 1526 o C SODIUM DISILICATE + LIQUID NEPELITE + LIQUID 768 o C T E M P E R T U R E o C Table (1).The result of shrinkage tests Length of samples Shrinkage of samples 1250ْ C 1300ْ C 1350ْ C 1250ْ C 1300ْ C Concentrati on of electrolyte solution Original state Drying state Firing state Drying state Firing state Drying state Firing state Drying state Firing state Total state Drying state Firing state 0 6 4.87 4. 64 4.75 4.62 4.89 4.75 18.833 4.723 22.661 20.833 2.7368 0.1% 6 5.4 4. 68 5. 6 4.64 5.16 4.63 10 13.33 22 6. 6667 17.143 0.2% 6 5.1 4. 69 4. 6 4.57 5.7 4.69 15 8.039 21.833 23.333 0.6522 0.5% 6 5.63 4.9 5. 4 4.32 4.54 4.16 6.1667 12.97 18.333 10 20 0.7% 6 4.54 4. 49 5. 4 4.48 5.2 4.59 24.333 1.101 25.167 10 17.037 1% 6 4.58 4.4 4. 7 4.62 4.76 4.32 23.667 3.93 26.667 21.667 1.7021 IBN AL- HAITHAM J. FO R PURE & APPL. SC I VO L. 23 (1) 2010 0 5 10 15 20 25 30 35 0 0.002 0.004 0.006 0.008 0.01 Electrolyte s oluti on T o ta l sh ri n k a g e 0 5 10 15 20 25 30 0 0.002 0.004 0.006 0.008 0.01 Ele ctrolyte s olu tion D ry in g sh ri n ka ge 0 5 10 15 20 25 0 0.002 0.004 0.006 0.008 0.01 Electrolyte solution F ir in g s h ri n k a g e ■ 1350C ▲1300C × 1250C ■ 135 0C ▲1300 C × 1250C Fig.(4):The change of firing shrinkage with concentration of electrolyte soluti on Fig. (5):The change of total shrinkage with concentration of electrolyte solution ■ 135 0C ▲1300 C × 1250C Fig. (3)The change of drying shrinkage with concentration of ele ctrolyte solution