International Journal of Civil Engineering and Technology (IJCIET) Volume 10, Issue 04, April 2019, pp. 2207–2215, Article ID: IJCIET_10_04_229 Available online at http://www.iaeme.com/ijmet/issues.asp?JType=IJCIET&VType=10&IType=4 ISSN Print: 0976-6308 and ISSN Online: 0976-6316 © IAEME Publication Scopus Indexed STUDYING THE EFFECT OF ADDING ANTIMONY (SB) TO THE LEAD BASE ALLOYS ON CORROSION IN ACIDIC MEDIUMS Aysha Shawkat Hasan, Yousif Khudhair Abbas and Nawzad Jalal Mahmood Northern University, Technical College/Kirkuk ABSTRACT Due to the toxicity and harmful environmental effect of (Pb) because the potential electrode values tendency to losses ions and oxidization, Antimony adding impact in the range of (2-15) wt. % to lead on the corrosion resistance, in three concentration of acidic acid solution with corrosion interval (288 hour), were investigated by weight loss measurements. The experimental results show that, antimony added to lead increase the corrosion resistance of lead, therefore the maximum total corrosion rate done in alloy1 for all concentration which used in previous work. It was (1.77133E-17MPY) for 0.1MHCl, (1.73E-17MPY) for 0.2MHCl and was (1.389E17MPY) for 0.3MHCl. Meanwhile the minimum total corrosion rate was in alloy4 for all concentration, it was (1.57E-17MPY) for 0.1MHCl, (1.39E-17MPY) for 0.2MHCl and (1.24E-17MPY) for 0.3MHCl. The general total corrosion rates degrease with increasing the concentration of corrosion medium, and the maximum average corrosion rates were in 0.1MHCl, wherever the minimum average corrosion rates were in 0.3MHCl.Howeve, the alloy (15%Sb-83.35%Pb) didn’t show the significant effect in corrosion resistance proportion to high Antimony contents comparison with the three first alloys. Key words: Lead, Antimony, Corrosion rates, weight losses Cite this Article: Aysha Shawkat Hasan, Yousif Khudhair Abbas and Nawzad Jalal Mahmood, Studying the Effect of Adding Antimony (Sb) to the Lead Base Alloys on Corrosion in Acidic Mediums, International Journal of Civil Engineering and Technology 10(4), 2019, pp. 2207–2215. http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=10&IType=4 1. INTRODUCTION Lead-antimony alloys are widely used in batteries. The metastable alloys are finding application in many industries like electronics and electrochemical, etc. (1). Some additive can be used to increase the strength and improve the castabilty of the pure lead due to its weakness, and antimony is added to improve the corrosion resistance (2). Lead is still the material of choice for use in ammunition despite concerns over its environmental impact. Its density, malleability and ready availability gives lead significant ballistic, production and cost advantages over substitute materials (3). In commercial application pure lead is never used, http://www.iaeme.com/IJCIET/index.asp 2207 editor@iaeme.com Aysha Shawkat Hasan, Yousif Khudhair Abbas and Nawzad Jalal Mahmood because the it is very soft and has high ductility, therefore its rarely used in alloys form. Alloying elements like Antimony, Calcium, Tin & Arsenic most common. Antimony generally is used to increase the mechanical properties, and its percentages in lead-antimony alloys from (0.5- 25%), however the range is (2 - 5 is the famous (4). Copper & Zinc containing Lead is good for mechanical properties and structural stability at high temperature. Lead-Antimony alloys have high corrosion resistance, they form a protective impermeable layer faster than a pure Lead. Lead alloys with more than 13% containing Antimony are rarely used because they are very brittle and don’t have high corrosion resistance (5). Several studies were done on the lead and its alloys. Ezenwa (6) was studied the improvement of the mechanical properties and corrosion resistance of Lead-Antimony alloy by adding the Sn to it, the obtained results shows the addition was increase the tensile strength, hardness & the corrosion resistance . Meanwhile the effect of sulfur addition to (PbSb-As-S) alloy in (H2SO4 ) solution were research by different methods like Linear sweep voltammetry, cyclic voltammetry and weight loss methods at room temperature by Ghasemi & Tizpar (2) was studied on the corrosion resistance, electrochemical properties and gas evolution, and the new alloy show high corrosion resistance. Oxygen and hydrogen over potentials estimation were greater than the specimens without Sulfur. The results show the Sulfur enlarge the anodic layer on the surface of (Pb-Sb-As) alloy, therefore the reaction impedance growth. Also the impact of this additive saw in the hardness batteries discharge capacities. Also Nwoye (7) was reported the increases of impact strength and hardness of (PbSb) melt with Copper powder dispersion when cooled. From the obtained results he show that increasing in the mechanical properties was due to using the pure Copper powder. The aim of this research the effect of adding Antimony with different percentages to Lead with availability of Copper & Zinc at constant percentages and its effect on corrosion or erosion by weight losses method was studied immersing the alloys in HCl solution with three different concentrations. 2. CASTING OF ALLOYS The lead, zinc, copper and antimony metals were brought from the state batteries manufacturing company with 99.9% purity. The manufacturing of samples by gravity casting procedure included: Weighting the alloying elements by using a sensitive balance with an accuracy of +0.0001 mg. Using an electrical furnace, the melting procedure was firstly performed by melting the lead, using an alumina crucible which was pre-heated in the furnace then the addition of the other elements was carried out at (650oC) holding temperature. During the addition of alloying elements to the molten lead, a manual stirring with a stainless steel rod was applied carefully to avoid producing too much dross. Pouring the molten alloys into a steel mould shown in figure (1) and then leaving the casting to cool to the room temperature. Four castings of lead-base white metals were manufactured with different additives. The preliminary chemical compositions were contained in table (1). http://www.iaeme.com/IJCIET/index.asp 2208 editor@iaeme.com Studying the Effect of Adding Antimony (Sb) to the Lead Base Alloys on Corrosion in Acidic Mediums Figure 1 Shows the dimensions of the gravity die mould (All dimensions in mm) Table 1 The preliminary chemical composition of the project samples Sample code %Cu %Zn Alloy1 Alloy2 Alloy3 Alloy4 1 1 1 1 0.65 0.65 0.65 0.65 Additive %Sb 2 3 4 15 Rest %Pb 96.35 95.35 94.35 83.35 3. PREPARATION OF SPECIMENS FOR CORROSION TESTS 1-The preparation procedure included turning specimens with the diameter (15mm) and length (13.5mm) for all specimens used in previous work. 2- After the specimen preparations for corrosion test the following mediums were prepared to immerse the specimens for variable times as shown in table (2), then the specimens were tested by weight loss method by using a 4-digital balance: Table 2 The chemical cleaning mediums (8). Specimen No. Medium 1A 2B 3C 4D 1A 2B 3C 4D 1A 2B 3C 4D 0.1 M HCl Time Hrs. Intervals of corrosion tests 288 hours 0.2 M HCl 24 Cleaning solution 100 ml -CH3COOH + 1000 ml distilled water(Boiled) Immersed for 5 minutes for each cleaning. 0.3 M HCl http://www.iaeme.com/IJCIET/index.asp 2209 editor@iaeme.com Aysha Shawkat Hasan, Yousif Khudhair Abbas and Nawzad Jalal Mahmood 2. Wet grinding. Grinding was performed by using emery paper with grades (220, 400, 800and 1000)(10). 3. Polishing. The polishing process was carried out by using alumina particles with size 0.3 μm, then specimens cleaned with water degreased with ethanol and dried (9). 4. DEVICES AND TOOLS USED IN THE PROCEDURE 1- Electric furnace. 2- Graphite crucible (1/2 Kg). 3- Digital balance (4-digits). 4- Hand saw. 5- Grinding and polishing machine. 6- Alumina solution (with particle diameters of 0.35 μm). 7- Clamp for handling the graphite crucible. 8- Volumetric flasks with different volume. 9- Container for storing specimens. 10- Drier machine for drying specimens. 11- Electric heater for boiling the mediums for cleaning. 12- Carbon steel mould (die). 5. CORROSION MEDIUM After prepare the specimens for corrosion test, the specimens marked to recognize one from another and immersion in selected medium in backer with (1000 mm) capacity. Three mediums used to corrosion tests in this work: 1-0.1M HCL. 2-0.2M HCL. 3-0.3M HCL. 6. CORROSION RATES CALCULATIONS To calculate the corrosion rates, when the corrosion tests finished the samples taken from the corrosion mediums and cleaned from the oxidation layers which caused due to test using smooth brush and then cleaning the surfaces by chemical cleaning suitable to the alloys shown in table (2), then followed by washing, drying and weighing the samples. These steps was repeated at the end of each interval of corrosion test to know the weight difference which caused by the corrosion, and the interval of corrosion mediums was (288hour). To calculate the corrosion rate following equation used(10): Corrosion rates (Miles per year) = ⁄ (1) Where 534: Constant W: The weight losses in (mg). D: The specimens density in (g/cm3), (11.27) for alloy1 & 2, (11.04) for alloy 3 & (10.66) for alloy 4 (11). A: The specimen’s area in (Sq. in). T: The exposure time to corrosion medium in (hour). http://www.iaeme.com/IJCIET/index.asp 2210 editor@iaeme.com Studying the Effect of Adding Antimony (Sb) to the Lead Base Alloys on Corrosion in Acidic Mediums In the previous work the corrosion rate equation also used to calculate the total corrosion rates (CrT). The difference was in substitution of weight and time, where weight was the difference between initial & final weight, meanwhile the time overall time of corrosion interval (288hr)(12). 7. RESULTS AND DISCUSSIONS The following results were obtained The four alloys which immersed in (0.1M HCL), show the maximum corrosion rates in the beginning corrosion intervals and the corrosion rates decrease with increasing exposure time to corrosion mediums, and all these and this behaviors for alloy 1,2,3, &4 clearly shown in figure(, (1, 2, 3 & 4) respectively. Corrosion Rates ( MPY) Corrrosion Rates ( MPY) 0.00E+00 0.00E+00 0 100 200 300 0 400 100 200 300 400 Time ( Hour) Time (Hour) Corrosion Rates (Mpy) Corrosion Rates ( MPY) Figure 1 Represent the corrosion rate for alloy (1) Figure 2:Represent the corrosion rate for alloy (2) in in 0.1M 0.1M 0.00E+00 0.00E+00 0 100 200 300 400 0 Time(Hour) 100 200 300 400 Time (Hour) Figure 3:Represent the corrosion rate for alloy (3) Figure 4 :Represent the corrosion rate for alloy (4) in in 0.1M 0.1M The four alloys which immersed in (0.2M HCL), show the maximum corrosion rates in the beginning corrosion intervals and the corrosion rates decrease with increasing exposure time to corrosion mediums, and all these and this behaviors for alloy 1,2,3, &4 clearly shown in figure(5, 6, 7&8) respectively. http://www.iaeme.com/IJCIET/index.asp 2211 editor@iaeme.com Corrosion Rates( MPY) Corrosion Rates(MPY) Aysha Shawkat Hasan, Yousif Khudhair Abbas and Nawzad Jalal Mahmood 0.00E+00 0 100 200 300 0.00E+00 400 0 100 Time (Hour) 200 300 400 Time (Hour) Corrosion Rates (MPY) Corrosion Rates (MPY) Figure 5:Represent the corrosion rate for alloy (1) in Figure 6 Represent the corrosion rate for alloy (2) in 0.2M 0.2M 0.00E+00 0.00E+00 0 100 200 300 400 0 100 Time( Hour) 200 300 400 Time (Hour) Figure 7 Represent the corrosion rate for alloy (3) in Figure 8 Represent the corrosion rate for alloy (4) in 0.2M 0.2M The four alloys which immersed in (0.3M HCL), show the maximum corrosion rates in the beginning corrosion intervals and the corrosion rates decrease with increasing exposure time to corrosion mediums, and all these and this behaviors for alloy 1,2,3, &4 clearly shown in figure(9, 10, 11 & 12) respectively. Corrosion Rates (MPY) Corrosion Rates (MPY) 0.00E+00 0.00E+00 0 100 200 300 400 0 Time ( Hour) 100 200 300 400 Time (Hour) Figure 9 Represent the corrosion rate for alloy (1) Figure 10 Represent the corrosion rate for alloy (2) in 0.3M in 0.3M http://www.iaeme.com/IJCIET/index.asp 2212 editor@iaeme.com Corrosion Rates ( MPY) Corrosion Rates ( MPY) Studying the Effect of Adding Antimony (Sb) to the Lead Base Alloys on Corrosion in Acidic Mediums 0.00E+00 0.00E+00 0 100 200 300 0 400 200 300 400 Time (Hour)) Time (Hour) Figure 11 Represent the corrosion rate for alloy (3) in 0.3M 100 Figure 12 Represent the corrosion rate for alloy (4) in 0.3M The possible reason for the low corrosion rates with increasing exposure to the medium of corrosion for all alloys which used in previous work due to the slow time speed of electrochemical interaction with continuously exposure to the corroded medium causes layer formation from membrane or remnants of corrosion on specimens surfaces prevent the electrochemical corrosion continuation which leads to reduce rates of the corrosion. Also because of the polarization happened, at the beginning of the corrosion the electrochemical interaction will be quickly lead to a high erosion rates, but with the time depletion of dissolved oxygen in the medium of corrosion, that leading to increase the concentration of hydrogen ions that accumulate on the lift pole referring to studies and researchers in (13 & 14). In general the maximum total corrosion rate done in alloy (1) for all concentration which used in previous work. It was (1.77133E-17MPY) for 0.1MHCl, (1.75E-17MPY) for 0.2MHCl and was (1.389E-17MPY) for 0.3MHCl. Meanwhile the minimum total corrosion rate was in alloy (4) for all concentration, it was (1.57E-17MPY) for 0.1MHCl, (1.39E-17MPY) for 0.2MHCl and (1.24E-17MPY) for 0.3MHCl. All these behaviors for alloy 1, 2, 3, &4 for three concentrations clearly shown in figure (13). The possible reason for this because the alloy (1) has the maximum content of Lead (96.5), Lead tend to oxidize due to its electrode potential (0.126v), , the increasing in Antimony percentages caused decreasing in total corrosion rates due to its electrode potential (+0.11v) which is less active, referring to studies and researchers in (3). From the obtained results, there weren’t significant effect of high Antimony content in alloy which represent in alloy (4) (5). And figure (13) can clearly shows these behaviors. http://www.iaeme.com/IJCIET/index.asp 2213 editor@iaeme.com Corrosion Rates /MPY) Aysha Shawkat Hasan, Yousif Khudhair Abbas and Nawzad Jalal Mahmood 0.00E+00 Alloy 1 0.1M 1.77E-17 0.2M 1.73E-17 0.3M 1.39E-17 Alloy 2 1.70E-17 1.63E-17 1.35E-17 Alloy 3 1.65E-17 1.45E-17 1.33E-17 Alloy 4 1.57E-17 1.39E-17 1.24E-17 Figure 13 Total Corrosion Rates for four Alloys in three concentration mediums The maximum average corrosion rates were in 0.1MHCl, wherever the minimum average corrosion rates were in 0.3MHCl. The figure (14) shows these behaviors. The possible reason of this behavior was because the high resistance electrolyte film which covered the corroded areas, so they cannot be polarized to the full cathodic protection potential (15). Avarage in 0.2MHCL Avarage in 0.3MHCL Corrosion Rates(Mpy) Avarage in 0.1MHCL 0.00E+00 24 48 72 96 120 144 168 192 216 240 264 288 Time(hours) Figure 14 The general corrosion rates for four alloys in three acidic concentration medium. 8. CONCLUSIONS The results were obtained for the three alloys with (2-4%Sb) which immersed in three concentration corrosive acidic medium, obviously display that the erosion effort exist more attacker, due to the following order of corrosion activity: Alloy1 > Alloy 2> Alloy 3> Alloy 4 http://www.iaeme.com/IJCIET/index.asp 2214 editor@iaeme.com Studying the Effect of Adding Antimony (Sb) to the Lead Base Alloys on Corrosion in Acidic Mediums The increasing in the interval of the corrosion time decreasing in the corrosion rate because of the layer formation which caused by the slow time speed of electrochemical interaction with continued exposure. The general total corrosion rates degrease with increasing the concentration of corrosion medium. The corrosion rate decreasing with increasing the Antimony percentages or contains in alloys for the three first alloys. However for the fourth alloys with (15%Sb-83.35%Pb) didn’t shows the significant effect in corrosion rates. REFERENCES [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] D Mukhewee and S Guruviah, Physical and Corrosion - Resistant Properties Of Rapidly Quenched Lead-Antimony And Lead-Antimony-Tin Alloys, Central Electrochemical Research Institute, Karaikudi - 623 006, Bulletin of Electrochemistry 1 (6) Nov. – Dec, pp. 539-541, 1985. Z. Ghasemi And A. Tizpar, Studies On Corrosion Resistance And Electrochemical Behavior Of Pb-Sb-As-S Alloys As Positive Grids In Lead-Acid Batteries, International Journal Of Electrochemical Science (2), Page 700 – 720, September 2007. Peter J. Hurley, The Structure, Redox Corrosion and Protection of Commercial LeadAntimony Shot, Blake International Limited, Maple Grove, Huddersfield United Kingdom, September 2013. VictorPocajt, Intoduction to total material, Italia, July 2015. Sivaraman Guruswamy,Engineering properties and Applications of Lead Alloys, New Yourk, November 1999. Ezenwa, Z.O., Equilibrium Studies of Lead-Tin-Antimony Alloys, B.Eng. Project Report, Enugu State University of Science & Technology, Enugu, p17-22, 1987. Nwoye, C. I., Effect of Copper Powder Dispersion on the Electrical Conductivity of LeadAntimony Alloy, M. Eng. Thesis, Nnamdi Azikiwe University, Awka, 2000. ASTM G1, Standard Practice for Preparing, Cleaning, and Evaluation Corrosion Test Specimens, April, 2012. ASM Hand book, Metallography and Microstructuresm Volume 9, 2004. Velayutham K., U. Arumugham, B. Kumarugur-rubaran, P. Gopal, Evaluation of the AntiCorrosive Coating on Railway Bogie Components, International Jounal of Engineering and Advanced Technology, 3(2): 2249-8958, 2013. Werner Martienssen, Hans Warlimont, Springer Handbook of Condensed Matter and Materials Data, 2006. Ehsan F. Abbas & Etal, Corrosion of Copper Weldments in Salty and Acidic Solutions, Tikrit Journal of Engineering Science Vol.15, No. 1, 2008. ASM Handbook. Volume 13 of the 9th Edition Metals Handbook, page 16, fourth printing 1992. Stephen C. D., "Galvanic Corrosion ", University of Delaware, U. S. A., (2003). Takso Omse and etal, Negative Corrosion of Lead- Antimony Alloys in Lead Acid Batteries at High Temperatures, Journal of power sources, , Pages 65-70, Volume 65, Issues 1-2, March-April 1997. http://www.iaeme.com/IJCIET/index.asp 2215 editor@iaeme.com