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Microstructure, Hardness and Wear Rate of A356 Aluminium Alloy Surface Alloyed with Nitrided Titanium using GTA

Affiliations

  • Department of Mechanical Engineering, Amrita School of Engineering - Coimbatore, Amrita Vishwa Vidyapeetham University, Coimbatore - 641112, Tamil Nadu, India

Abstract


Background/Objectives: The study aims to improve surface properties of aluminium A356 alloy by surface alloying it with nitrided titanium, in a nitrogen environment, using Gas Tungsten Arc (GTA) as heat source. Methods/Statistical Analysis: Nitrided titanium sheets were surface alloyed with cast aluminium A356 blocks, in nitrogen environment, with GTA as heat source for melting. The cross-sectional microstructure of the specimens was studied using inverted metallurgical microscope. Further analysis was carried out using SEM/EDS to identify the formation of nitrides and intermetallic compounds. The hardness of the specimens was measured using Vickers hardness tester and the wear rate was determined using pin-on-disc wear tester. Findings: Microstructure analysis revealed a uniform and granular refined structure in the modified layer compared to the coarse and dendritic structure of the cast block. EDS analysis indicated the formation of hard-intermetallic compounds. The hardness was measured to be highest at the surface of the central fusion zone, with a maximum value of 656 HV while as-cast aluminium block exhibited only 76 HV. The measured wear rate was 10×10-4 mm3/m for the modified layer, compared to 52×10-4 mm3/m of the substrate. Alongside, the loss in weight after wear dropped by 4 mg. The coefficient of friction of the modified surface showed a constant trend during the wear-off period. The enhancement in these surface properties is attributed to the formation of nitrides and other intermetallic compounds that in the modified layer during surface alloying. Additionally, the use of GTA as heat source renders the surface alloying process to be economically feasible relative to other employable methods. Applications/Improvements: The devised surface alloying method used to enhance the surface properties of A356 is cheap, flexible and effective and finds intensive application in marine, automotive and manufacturing sectors.

Keywords

A356, Gas Tungsten Arc, Hardness, Nitriding, Surface Alloying, Titanium, Wear Rate.

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References


  • Kaufman JG, Rooy EL. Aluminum alloy castings: properties, processes, and applications: Asm International. 2004.
  • Richter E, Gunzel R, Parasacandola S, Telbizova T, Kruse O, Moller W. Nitriding of stainless steel and aluminium alloys by plasma immersion ion implantation. Surface and Coatings Technology. 2000 Jun; 128:21–7.
  • Chen HY, Stock HR, Mayr P. Plasma-assisted nitriding of aluminum. Surface and coatings technology. 1994 Jun; 64(3):139–47.
  • Kaczmarek L, Sawicki J, Kyziol K, Siniarski D, Jonas S, Steglinski M. Surface modification of aluminium-lithium alloy using prenitriding option and SixNy coating deposition. Journal of Achievements in Materials and Manufacturing Engineering. 2009; 37(2):282–5.
  • Meneau C, Andreazza P, Andreazza-Vignolle C, Goudeau P, Villain JP, BoulmerLeborgne C. Laser surface modification: structural and tribological studies of AlN coatings. Surface and Coatings Technology. 1998 Mar; 100:12–6.
  • Sundgren JE. Structure and properties of TiN coatings. Thin solid films. 1985; 128(1):21–44.
  • Hsieh J, Liang C, Yu C, Wu W. Deposition and characterization of TiAlN and multilayered TiN/TiAlN coatings using unbalanced magnetron sputtering. Surface and Coatings Technology. 1998 Sep; 108:132–7.
  • Munz WD. Titanium aluminum nitride films: A new alternative to TiN coatings. Journal of Vacuum Science and Technology A. 1986 Apr; 4(6):2717–125.
  • Zukerman I, Raveh A, Kalman H, Klemberg-Sapieha J, Martinu L. Thermal stability and wear resistance of hard TiN/TiCN coatings on plasma nitrided PH15-5 steel. Wear. 2007 Sep; 263(7):1249–52.
  • Sproul WD, Legg KO. Advanced surface engineering: opportunities for innovation: Technomic. 1995.
  • Bressan J, Hesse R, Silva E. Abrasive wear behavior of high speed steel and hard metal coated with TiAlN and TiCN. Wear. 2001 Oct; 250(1):561–8.
  • Brogren M, Harding GL, Karmhag R, Ribbing CG, Niklasson GA, Stenmark L. Titanium–aluminum–nitride coatings for satellite temperature control. Thin Solid Films. 2000 Jul; 370(1):268–77.
  • Liang W, Zhao X. Improving the oxidation resistance of TiAl-based alloy by siliconizing. Scripta materialia. 2001; 44(7):1049–54.
  • Wenbin D, Haiyan J, Xiaoqin Z, Dehui L, Shoushan Y. Microstructure and mechanical properties of GTA surface modified composite layer on magnesium alloy AZ31 with SiC P. Journal of Alloys and Compounds. 2007 Feb; 429(1):233–41.
  • Hioki S, Yamada T, Hatano K, Haneda M, Imanaga S. Method for melt nitriding of aluminum or its alloy. Google Patents; 1981 Jan.
  • Saravanan R, Sellamuthu R. An Investigation of the Effect of Surface Refining on the Hardness and the Wear Properties of Al-Si Alloy. Applied Mechanics and Materials; Trans Tech Publ. 2014 Jul; 53–7.
  • Heydarzadeh Sohi M, Ansari M, Ghazizadeh M, Zebardast H. Liquid phase surface nitriding of aluminium using TIG process. Surface Engineering. 2014 Dec; 31(8):598–604.
  • Zheng X, Ren Z, Li X, Wang Y. Microstructural characterization and mechanical properties of nitrided layers on aluminum substrate prepared by nitrogen arc. Applied Surface Science. 2012 Oct; 259:508–14.
  • Kou S. Welding Metallurgy 2nd edn. 2nd edition John Wiley & Sons, New Jersey, USA. 2003.
  • Dyuti S, Mridha S, Shaha S. Surface modification of mild steel using tungsten inert gas torch surface cladding. American Journal of Applied Sciences. 2010 Jun; 7(6):815–22.
  • Sivachidambaram P, Balachandar K. Optimization of Pulsed Current TIG Welding Parameters on Al-SiC Metal Matrix Composite-An Empirical Approach. Indian Journal of Science and Technology. 2015 Sep; 8(23):1–7.
  • Arul S, Sellamuthu R. Application of a simplified simulation method to the determination of arc efficiency of Gas Tungsten Arc Welding (GTAW) and experimental validation. International Journal of Computational Materials Science and Surface Engineering. 2011; 4(3):265–80.
  • Saravanan R, Sellamuthu R. Determination of the Effect of Si Content on Microstructure, Hardness and Wear Rate of Surface-refined Al-Si Alloys. Procedia Engineering. 2014 Dec; 97:1348–54.
  • Boyer R, Welsch G, Collings E. Materials Properties Handbook: Titanium Alloys. ASM International, Materials Park, USA. 1994.
  • Teker T. Effect of synergic controlled pulsed and manual gas metal ARC welding processes on mechanical and metallurgical properties of AISI 430 ferritic stainless steel. Archives of Metallurgy and Materials. 2013 Dec; 58(4):1029–35.
  • Mridha S. Titanium nitride layer formation by TIG surface melting in a reactive environment. Journal of Materials Processing Technology. 2005 Oct; 168(3):471– 7.
  • Stott F, Mitchell D, Wood G. The influence of temperature on the friction and wear of thin ceramic coatings in carbon dioxide. Journal of Physics D: Applied Physics. 1992 Jan; 25(1A):189–94.

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