65- 72 Khwarizmi Engineering Journal, Vol. 1-Al f CorrosionoInteraction f 1100o Alalkawi H.J.M Department of Electromechanical Engineering/ University of Technology * Materials Engineering/ fDepartment o ***,** ***E (Received Abstract Corrosion-fatigue occurs by the combined actions of cyclic loading peening on cumulative corrosion-fatigue life of 1100 were submerged in 3.5%NaCl solution for 71 days. Constant fatigue tests were performed with and without corrosive environment. Cumulative corrosion-fatigue tests were also carried out in order to determine the fatigue life before after shot peening. The constant fatigue life was fatigue limit was reduced by 13% compared with dry fatigue. In case of shot life was increased by a factor of about (2) compared with cumulative corrosion found that the CFLIF%(Cumulative Fatigue Life Improvement Factor) was about (2 treatment . Keywords: Corrosion -fatigue , shot peen 1. Introduction If the metals are exposed to the concurred actions of repeated stress and corrosive environment, then its fatigue behavior will become quite different from that in air ,it means that there is a significant decrease in fatigue strength and fatigue life[1].In case of light metals the presence of corrosion is known to reduce their strength significantly ,thus it does great harm to engineering structural integrity of frames ,especially those working in marine environment [2]. The combined action of corrosion an repeated stresses defined by corrosion fatigue .The effect of corrosive actions on a metal surface may cause a general roughening to the surface and lead to the generation of crevices and pits at different points on the surface which result in a greater loss in fatigue strength of the metal when it subjected to fluctuating stresses at the same (201 72 -65, P.P. 1, No. 1Khwarizmi Engineering Journal, Vol. 1 nd Shot Peening aCumulative Fatigue -f Corrosion Aluminum Alloy H12-f 1100 dMaajee Amer Hameed *Alalkawi H.J.M Zainab Azeez Betti*** Department of Electromechanical Engineering/ University of Technology Mustansiriya University -AlCollege of Engineering/ Materials Engineering/ Alalkawi2012@yahoo.com :mail-*E amer.h.m.altaee@gmail.com :mail-**E faithful_mind1990@yahoo.com :mail-***E 2014) October 282014; accepted May 11(Received atigue occurs by the combined actions of cyclic loading and corrosive environment fatigue life of 1100-H12 Al alloy was investigated. Before f solution for 71 days. Constant fatigue tests were performed with and without corrosive fatigue tests were also carried out in order to determine the fatigue life before after shot peening. The constant fatigue life was significantly reduced due to corrosive environment and the endurance fatigue limit was reduced by 13% compared with dry fatigue. In case of shot peening the cumulative , corrosion increased by a factor of about (2) compared with cumulative corrosion-fatigue life without shot peening. that the CFLIF%(Cumulative Fatigue Life Improvement Factor) was about (2-6) due to shot peening surface fatigue , shot peening , 1100-H12 Al alloy, cumulative fatigue damage If the metals are exposed to the concurred actions of repeated stress and corrosive environment, then its fatigue behavior will become quite different from that in air ,it means that there is a significant decrease in fatigue n case of light metals the presence of corrosion is known to reduce their strength significantly ,thus it does great harm to engineering structural integrity of frames ,especially those working in marine environment [2]. The combined action of corrosion and repeated stresses defined by corrosion fatigue .The effect of corrosive actions on a metal surface may cause a general roughening to the surface and lead to the generation of crevices and pits at different points on the surface which result in a loss in fatigue strength of the metal when it subjected to fluctuating stresses at the same time, than when each factor acts separately. Corrosion fatigue is considered as the reason of a wide variety of failures in service, including, for example, marine propeller shafts, boiler and superheater tubes, turbine and pump components, and pipes carrying corrosive liquids,...etc. [3]. One of the most important remedies for corrosion fatigue is shot peening a process in which a round metallic thrown on the metal surface at a relatively high velocity(10-40m/sec) and it also known as acold working method . Each shot makes a small dent in the metal surface . A plastic flow of the surface grains is generated by the shot impact. There is a several parameters that affect on this process such as (the kinetic energy , impinging angle of the shot impact , the physical properties of the surface (hardness , toughness),...etc). Fatigue failure, (which cause about 90% of the mechanical catastrophic Khwarizmi-Al Engineering Journal )5(201 nd Shot Peening ** d Department of Electromechanical Engineering/ University of Technology Mustansiriya University and corrosive environment. The effect of shot Al alloy was investigated. Before fatigue testing, specimens solution for 71 days. Constant fatigue tests were performed with and without corrosive fatigue tests were also carried out in order to determine the fatigue life before and significantly reduced due to corrosive environment and the endurance peening the cumulative , corrosion -fatigue tigue life without shot peening.It was 6) due to shot peening surface . time, than when each factor acts separately. Corrosion fatigue is considered as the reason of a wide variety of failures in service, including, for propeller shafts, boiler and superheater tubes, turbine and pump components, and pipes carrying corrosive liquids,...etc. [3]. One of the most important remedies for corrosion fatigue is shot peening .Shot peening is a process in which a round metallic shot is thrown on the metal surface at a relatively high 40m/sec) and it also known as acold- working method . Each shot makes a small dent in the metal surface . A plastic flow of the surface grains is generated by the shot impact. There is a several parameters that affect on this process such as (the kinetic energy , impinging angle of the shot impact , the physical properties of the surface (hardness , toughness),...etc). Fatigue failure, (which cause about 90% of the failures in metal parts )(2015 72 -65Khwarizmi Engineering Journal, Vol. 11, No. 1, P.P. -Al Alalkawi H.J.M 66 and structures) largely start at surface cracks that grow under tensile stresses ;thus shot peening generally results in considerably greater fatigue strength because the residual compressive stresses caused by shot peening will counteract the applied tensile stresses on the metal surface[4]. Menan and Hénaff [5]investigated the interactions between mechanical, environmental and microstructural parameters during corrosion fatigue crack growth of 2024 Al alloy using 3.5% NaCl solution .it was found that the corrosion crack growth rate is higher in NaCl solution than in air or distilled water. Alalkawi et al.[6] examined constant and cumulative fatigue test under the effect of shot peening treatment for two aluminum alloys 2024 and 5052 .It was concluded for 2024 Al alloy that as the shot peening time increases the cumulative fatigue life is improved but above 10 min. The fatigue life is reduced .While shot peening reduced the fatigue life of 5052 Al alloy. Gao.Y.K. [7] studied the fatigue behavior of 7050-T7451aluminum alloy for machined ,laser and shot peened specimens . Results indicated that laser and shot peening improve the fatigue life and strength compared to the unpeened results. Dong et al. [8] predicted the effect of prior corrosion on the crack propagation of aluminum alloy based on scanning electron microscope (SEM).Results indicated that corrosion pits increases the crack growth rate which can be empirically expressed by the term of ( ak n maxσ ). Ford. F.P.[9] studied the corrosion fatigue crack propagation rates for aluminum-7% magnesium. It is suggested that the cracking mechanism is slip dissolution and the rate determining steps increase the crack growth. Laurino et al.[10] studied the fatigue behavior of 6101 Al alloy under corrosive media and it was found that corrosion -fatigue interactions reduced the fatigue life of the 6101 Al alloy. The main goal of this work is to report experimental evidence about the constant fatigue and fatigue damage accumulation behavior of 1100- H12Aluminum alloy under corrosion fatigue and studying the effect of shot peening process on the mechanical behavior of the mentioned alloy. 2. Experimental Procedures Aluminum of the 1100-H12 class is used in the current work and it is primarily used in applications where electrical conductivity , formability , ductility , and the resistance to stress corrosion are more important than strength. Chemical analysis of the metal used was tested at ( State Company for Inspection and Engineering Rehabilitation(SIER) in Iraq).The results, which are compared to the American Society for Testing and Materials (ASTM B209) [11], are summarized in Table (1) below while the mechanical properties are listed in Table (2) . Table 1, Chemical composition of 1100 Al alloy in wt%. *Other elements include (Cr ,Ni, Ti ,Pb, Co)when tested experimentally they found to be in the following percentages (0.003, 0.002, 0.006 ,0.0006, 0.001) respectively. Table 2, Mechanical properties of 1100 Al alloy. Alloying element% Si Fe Cu Mn Mg Zn Other elements* lA ]11B209 [ ASTM 0.95 0.2 -0.05 0.05 0.05 0.1 0.15 Rem Measured 0.112 0.447 0.3 0.017 0.004 0.015 0.0126 Rem Property Ultimate Tensile strength MPa Yield Strength Mpa Elongation % In 100 mm Modulus of Elasticity Gpa ASTM B209[11] min.= 96.5 min.=75.8 min.=6 70 Measured 107 82 7 71 Alalkawi H.J.M 3. Testing Procedures 3.1. Tensile Testing The experimental mechanical properties listed in table (2) above were measured using (WDW 200E) tensile test apparatus with a capacity of 200KN. The tensile specimen was taken according to American Society for Testing and Materials (ASTM B209) .shape and dimensions of the tensile specimen is illustrated in Fig.1. Tensile test specimen according to ASTMB209. 3.2. Fatigue Testing The AVERY Fatigue Testing Machine Type 7305 was used to apply reverse loads with or without an initial static load as shown in figure (2). The fatigue test is a cyclic bending loading procedure with R=-1. The purpose of the test is to generate S-N data (stress vs. number of cycles) for metal used. Fig. 2. Fatigue testing machine Shape and dimensions of Fatigue test specimen is shown in Figure (3) below: Khwarizmi Engineering Journal, Vol. 11, No. 1, P.P. -Al 67 The experimental mechanical properties listed in table (2) above were measured using (WDW- 200E) tensile test apparatus with a capacity of specimen was taken according to American Society for Testing and terials (ASTM B209) .shape and dimensions of the tensile specimen is illustrated in Figure (1) . Tensile test specimen according to The AVERY Fatigue Testing Machine Type- was used to apply reverse loads with or without an initial static load as shown in figure The fatigue test is a cyclic bending loading 1. The purpose of the test is to data (stress vs. number of cycles) for achine. of Fatigue test ) below: Fig. 3. Shape and dimensions all dimensions in mm) D3479/D3479M–96 standard 3.3. Corrosion Test The specimens before fatigue testing were immersed in a 3.5%NaCl solution for (71 especially those serving in marine environment (sea water)[12]. 3.4. Shot Peening Procedure The specimens were shot peening treated from using tumbleset control all sides OB Machine No. 03008 -Model STB tusraappa propertieswith the following verage ball size = 0.6 mm A = cast steel Ball material Rockwell hardness = ( 48 bars. = 12 Pressure = 40 m/sec . Velocity Shot peening is carried out on fatigue specimens at different time intervals which are (10 , 20, 30 ) minutes. The is shown in Figure (4) below Fig. 4. Shot peening apparatus )(2015 72 -65Khwarizmi Engineering Journal, Vol. 11, No. 1, P.P. imensions of fatigue specimen ( ) according to ASTM 96 standard The specimens before fatigue testing were NaCl solution for (71)days especially those serving in marine environment Peening Procedure The specimens were shot peening treated from anel pusing tumbleset control OB Machine No. 03008 : properties . verage ball size = 0.6 mm . = cast steel )HRC . 50 -Rockwell hardness = ( 48 is carried out on fatigue specimens at different time intervals which are he shot peening apparatus below: Shot peening apparatus. Alalkawi H.J.M 4. Experimental Results and Discussion 4.1. Fatigue Results Fatigue analysis are normally based on the results obtained from constant amplitude Table 3, Fatigue results. Theta � °� � Specimens No. 12° 1,2,3 10° 4,5,6 6° 7,8,9 4° 10,11,12 12° 13,14 ,15 10° 16,17 , 18 6° 19,20 ,21 4° 22, 23, 24 From the Table (3) above ,it is clear that there is no effect of corrosion on fatigue life at LCF(Low Cycle Fatigue) .The reason of this finding is due to dominate parameter of the applied load .While the corrosion is not significantly influence on the fatigue life[ following figure (see ,fig.5), indicate that the fatigue life of pre-corroded specimens d compared with that of as-received specimens Also the fatigue strength is reduced by a factor of 13% compared with dry fatigue strength . An approximately 60% decrease in fatigue strength of 7075-T6 A l-alloy was found by Genel[ the same conditions of the present work. The conventional ,constant stress amplitude S N curves for the above conditions are shown in the following Figure (see, Fig. 5) : Fig. 5. Conventional ,constant stress amplitude S curves for dry and corrosion fatigue conditions Khwarizmi Engineering Journal, Vol. 11, No. 1, P.P. -Al 68 nd Discussion atigue analysis are normally based on the from constant amplitude continuous cycling tests. Thus , the first step of work was to establish the base specimens (dry fatigue ) and 12 specimens for( corrosion- fatigue) which were immersed in 3.5% NaCl solution for 71 days .The resu tabulated in Table (3) as shown below: Dry condition Nf Cycles Applied stress Mpa 19000 , 14000, 16500 441 21000, 27000, 24000 393 276000 , 211000 ,245000 195 2713000, 2870000 ,2960000 (unfailed specimens ) 137 71 days corrosion condition 13000 , 14000 , 18000 441 23000 , 24000 ,22000 393 252000 , 209000 , 233000 195 684280 , 688740 , 693200 137 ,it is clear that there is no effect of corrosion on fatigue life at ) .The reason of this finding is due to dominate parameter of the applied load .While the corrosion is not significantly influence on the fatigue life[13]. The indicate that the corroded specimens decreased received specimens. Also the fatigue strength is reduced by a factor of 13% compared with dry fatigue strength . An approximately 60% decrease in fatigue strength of was found by Genel[14] using conditions of the present work. ,constant stress amplitude S- N curves for the above conditions are shown in ,constant stress amplitude S-N curves for dry and corrosion fatigue conditions. The S-N curves has been used by several workers to evaluate the cumulative fatigue damage .The Endurance limit at 10 reduction factor for dry and corrosion fatigue conditions are shown in Table (4). P.S.Pao et al. [13]tested 7075-T351 Aluminum alloy under fatigue loading using the 3.5%NaCl solution as a medium. They found that the threshold stress levels are significantly reduced due to the presence of corrosion pits. The presence of a corrosive environment during fatigue loading eliminates the fatigue limit for the metal used [15]. )(2015 72 -65Khwarizmi Engineering Journal, Vol. 11, No. 1, P.P. continuous cycling tests. Thus , the first step of work was to establish the base - line data for 12 specimens (dry fatigue ) and 12 specimens for( fatigue) which were immersed in 3.5% NaCl solution for 71 days .The results are Table (3) as shown below: Nf , Average 16500 24000 244000 2847667 2713000, 2870000 ,2960000 15000 23000 231333 688740 N curves has been used by several workers to evaluate the cumulative fatigue damage .The Endurance limit at 107 cycles and reduction factor for dry and corrosion fatigue conditions are shown in Table (4). P.S.Pao et al. T351 Aluminum alloy under fatigue loading using the 3.5%NaCl solution as a medium. They found that the threshold stress levels are significantly reduced due to the s. The presence of a corrosive environment during fatigue loading eliminates the fatigue limit )(2015 72 -65Khwarizmi Engineering Journal, Vol. 11, No. 1, P.P. -Al Alalkawi H.J.M 69 Table 4, .actorfeduction rnd aycles c 7t 10aimit lEndurance 4.2. Cumulative Fatigue Damage Results Most engineering components in service are subject to a complex , non-constant ,state of stress .Each cycle or group of cycles at a particular amplitude induces damage to the component : the addition of all this damage is called Cumulative Damage (CD) .In laboratories ,CD is usually examined by testing specimens with a definite number of cycles at one stress level ,and then to continue the test at other stress levels till failure [16] Cumulative fatigue results for 71 days corrosion are listed in Table (5) below: Table 5, Cumulative fatigue results for 71 days corrosion. Table (6) illustrate the cumulative corrosion- fatigue with the interaction of shot peening at different times of peening. 6, Table .Interaction of 71 days cumulative corrosion fatigue with shot peening for different times Shot peening time -10 min Average f N Nf Loading Sequence (MPa) Specimens No. 54000 50000 58000 58000 H-L 441) -(195 33 , 34 , 35 44200 43000 41600 48000 L-H 195) -(441 36 , 37 ,38 Shot peening time -20 min 50000 50000 , 50000, 50000 H-L 441) -(195 39 , 40 , 41 46500 47000 , 46000 , 46500 L-H 195)-(441 42 , 43 , 44 30min-ot peening time hS 43000 , 4300038000 , 48000 H-L 441) -(195 7, 4 6, 4 54 54500 54000 , 55000 , 54500 L-H 195)-(441 48 , 49 , 50 Reduction Factor cycles 7 Endurance limit at 10 Equations Condition 13% 62 Mpa σf = 3982.5 Nf -o.232 Dry fatigue MPa 55 0.338 - f=12931 N f σ Corrosion fatigue Nf av. Nf Cycles Loading sequence (MPa) Specimen No. 26500 22000, 25000 28000,31000 H-L 441) -(195 25 , 26 , 27 , 28 34750 45000 , 36000 , 29000 , 29000 L-H 195)-(441 29 , 30 , 31 , 32 )(2015 72 -65Khwarizmi Engineering Journal, Vol. 11, No. 1, P.P. -Al Alalkawi H.J.M 70 4.3. Cumulative Fatigue Life Improvement Factor(CFLIF%) The percentage of cumulative fatigue life improvement factor can be calculated by the following equation (eq.1) [17] : CFLIF% = �� ��� �� ��.������ ����� ��.� � ��� �� ��.���� � × 100 …(1) where : Nf (corr.+sp) =No. of cycles to failure at the interaction of corrosion fatigue with shot peening (sp) for two stress levels. Nf( corr.) =No. of cycles to failure at corrosion environment for two stress levels . shows the CFLIF% results. (7) Table Table7 he interaction of corrosion fatigue with shot peeningResults of CFLIF% under t 30 min. 20 min. 10 min. Shot Peening Time 441 -195 441 -195 441 -195 H (MPa)-L 195 -441 195 -441 195 -441 L (MPa)-H 4.53 5.85 6.53 %CFLIF 4.138 2.72 2.26 It can be noticed that the CFLIF% is positive and this means that SP treatments improved the cumulative corrosion-fatigue life of 1100 Al alloy.In general shot peening had a noticeable effect on cumulative fatigue life ,see table(7).The process of shot peening affect on crack growth life by increasing the time to failure by a factor of ( 2 - 4 ) for the lower applied stresses or by a factor of (1.2 - 2.7) for the higher stress levels [18]. In the present work ,shot peening improved the corrosion-cumulative fatigue life by a factor of approximately (2). Seong et al. [12] studied the effect of shot peening on the fatigue life of 7075-T6 using 3.5% NaCl solution for one week to one year under room temperature .They concluded that the shot peening has superior effectiveness to increase the corrosion-fatigue life and improved the fatigue limit by 24% compared with corrosion fatigue limit . 5. Conclusions From the current work on the interaction of cumulative corrosion-fatigue and shot peening process of 1100 Al alloy, the following remarks can be derived : 1. Constant fatigue life was significantly reduced under corrosive environment and the fatigue strength was reduced by a factor of 13%. 2. CFLIF% was found to be from (2 - 6). 3. Shot peening improved the cumulative corrosion-fatigue life by a factor of about (2). 4. Shot peening is a useful method for components working under corrosive environment. 6. References [1] Y Murakami; R O Ritchie "Comprehensive structural integrity: cyclic loading and fatigue" Vol.4 , pp 345, Elsevier Pergamon, (2003) . [2] R.H.Oskouei, R.N.Ibrahim " Restoring the tensile properties of pvd-tin coated al 7075 - t6 using a post heat treatment" surface coating technology 205(15),pp3967- 3973, (2011) . [3] Peter George Forrest , "Fatigue of metals ", pp1,205 , Pergamon Press, (1962). [4] Kiyoshi Funatani ,Lin Xie ( Handbook of Metallurgy Process Design edited by George E.Totten ) , CRC Press , pp 858 ,(2006). [5] F. Menan and G. Hénaff."Synergistic action of fatigue and corrosion during crack growth in the 2024 aluminium alloy", Procedia Engineering, Vol. 2, pp.1441-1450, (2010). [6] Hussain J.M. Alalkawi , Qusay Khalid Mohammed, Waleed Sadun Al-Nuami "The effect of shot peening and residual stresses on cumulative fatigue damage" Eng.& Tech., Vol.28, No.15,(2010). [7] Y.K. Gao "Improvement of fatigue property in 7050–T7451 aluminum alloy by laser peening and shot peening" Materials Science and Engineering: A , Vol. 528, Issues 10–11, pp 3823–3828 , (25 April 2011). )(2015 72 -65Khwarizmi Engineering Journal, Vol. 11, No. 1, P.P. -Al Alalkawi H.J.M 71 [8] Li Xu-Dong, Wang Xi-Shu, Ren Huai-Hui, Chen Yin-Long, Mu Zhi-Tao."Effect of prior corrosion state on the fatigue small cracking behavior of 6151-T6 aluminum alloy" , Corrosion Science, Vol. 55,pp. 26–33, (2012). [9] F. P. Ford "corrosion fatigue crack propagation in aluminum-7% magnesium alloy" science and engineering, Vol. 35, No. 7, pp. 281-287, (July 1979. published online 2013). [10] A. Laurino, E. Andrieu, J.-P. Harouard, G. Odemer, J.-C. Salabura, C. Blanc "Effect of corrosion on the fatigue life and fracture mechanisms of 6101 aluminum alloy wires for car manufacturing applications" Materials & Design ,Vol. 53, pp 236–249 ,(January 2014) . [11] Annual Book of ASTM Standards, (Standard Specification for Aluminum and Aluminum- Alloy Sheet and Plate), American Society for Testing and Material, Vol. 02.02,section2, pp298,(2009). [12] Seong K.C,Ji H.N.,Hao H.L.,Tao H.L., Tae H.K." Effects of shot peening on the corrosion fatigue life of Al 7075-T6 ", ICSP9:shot peening (2005). [13] P.S.Pao, S.J.Gill, C.R.Feng, "On fatigue crack initiation from corrosion pits in 7075- T7351 aluminum alloy" Scripta Materialia ,Vol.43, pp.391-396, (2000). [14] K. Genel. "The effect of pitting on the bending fatigue performance of high-strength aluminum alloy", Scripta Materialia, Vol. 57, pp.297–300, (2007). [15] Kimberli Jones, David W.Hoeppner" The interaction between pitting corrosion ,grain boundaries ,and constituent particles during corrosion fatigue of 7075-T6 aluminum alloy" Int.J.Fat. , Vol.31 , pp 686-692 ,(2009). [16] Miller,K.J. , Mohamed H.J.Alalkawi , De.Los.Rios,( Fatigue Damage Accumulation Above And Below The Fatigue Limit )European Group on Fracture Publication No.1, EGFI , London ,(1986). [17] Sharp P.K ,Barter S.A, Clark G." localized life extension specification for the F/A-18 Y470 X19 pocket" ,Melbourne:DSTO-TN- 0279,(2000). [18] R.A.Everett , W.T.Matthews ,R.Prabhakaran, J.C.Newman, M. J. Dubberly " The Effects of Shot and Laser Peening on Fatigue Life and Crack Growth in 2024 Aluminum Alloy and 4340 Steel" NASA/TM (2001). ا�����وي��� )2015( 72 -65، ! �� 1ا���د، ���11 ا���ارز�� ا������� ا������ ��� 72 �3H12-1100ا45 �123& ا��0ل ا�.&ا,�� ا�.-,�� �+ ا�*(ف '���&%�ت ��#��� ا�����م ا�����وي��� ***ز��6 **�7' 8%86 9�%& ���� ���� *��� �� ا����و������� *�� �&'�� &ا�%��$� ا�#��/ "! ھ �� ا�*&اد ***،** ����/ "! ھ�� ا�%��$� ا�*!#�.�-� /,+�� ا�� Alalkawi2012@yahoo.com :/ا��0#�و� � *ا��1- amer.h.m.altaee@gmail.com :/ا��0#�و� � ** ا��1- ***� faithful_mind1990@yahoo.com: ا��0#�و�/ ا��1- �!0� ا� 6�ث ا��4ل ا�#�,+/ 2&-��GH��2ف ����2-�ت C D+C*� @�ا, ا��4ل @*B درا�� @?<�� ا�#.+��.ط� @?<�� ��,= �2> ا�6*; ا��وري وا�&�8 ا�7#,+/ @ ا'�اء .-&م "1; ا'�اء �Q&6Rت ا��4ل) ٧١(�*�ة ٣.٥NaCl%@ J*� ا�$���ت 2*6+&ل -6#&ي H12-(1100 . �1!� D+C(ا�#7,+/ �!���1 ا�0*��&م ,��G @ ا'�اء �Q&6Rت @�ا, ا��4ل ا�#�,+/ ��Wض ا-%�د اC*�ر ا�$���ت "1; و$2� C*+�� ا�GHف . �Q&6Rت ا��4ل <�2#� ا�!$� �U و 2�ون ا�&�8 ا�#�,+/ � �Q&6Rت ا�!$� ا��X2 Bَ+" �#2�Z. ����2-�ت �C ر ا��4ل�*C�1 ا!�و'� . ��Hر�� �U ا��4ل ا�%�ف ١٣%; وا[\ �#�%� �+&�8 ا�#�,+/ وان ]� ا��4ل "َ; 2 @ ا�#&Q; ا�D ان �H� . ) %C _`Q&2�1!� �-&a�)CFLIF*� ا��4ل ا�#�ا,*/