Authors
School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran
Abstract
Friction stir processing was carried out on an AZ31 substrate with and without introduction of nano-sized TiC powder. Clusters of TiCwere found in the fabricated layer with a non-uniform distribution. Applied additional passes resulted in gradual break-up of TiC clusters; a nano-composite layer with a uniform dispersion of nano-sized TiC reinforcements in a matrix of fine grains (~3mm) was achieved after three further passes. This layerexhibited a micro hardness and yield strength of ~91HV and 290MPa, respectively. These values are found to be ~1.5 and 1.3 times of those of the as-received AZ31 substrate, respectively.Enhancement of mechanical properties is attributed to dispersion of nano-sized hard reinforcements in a matrix of fine grains. The layer produced without introduction of TiC powder showed a microstructure of fine grains (~5.5mm). However, it exhibited a lower micro hardness and yield strength than those of the as-received AZ31; this softening is related to dissolution of an intermetallic compound phase during the thermo-mechanical phenomena associated with friction stir processing.
Keywords
- Mordike, B. L., Ebert, T., Magnesium, Properties Applications Potential, Materials Science and Engineering A. 302 (2001) 37–45.
- Zhiye, H., Yang Liu, X., Review of Recent Studies in Magnesium Matrix Composites, Materials Science and Engineering A. 39 (2004) 6153–6171.
- Paskaramoorthy, R., Bugarin, S., Reid, R., Effect of an Interphase Layer on the Dynamic Stress Concentration in a Mg-matrix Surrounding a SiCparticle, Compound Structure. 9 (2009) 451–460.
- Lianxi, H.,Erde, W., Fabrication and Mechanical Properties of SiCw/ZK51A Magnesium Matrix Composite by Two-step Squeeze Casting, Materials Scienceand Engineering A. 278 (2000) 267.
- Thomas, W. M., Nicholas, E. D., Need-ham, J. C., Much, M. G., Optimum Processing and Tool Controls for Three- dimensional Friction Stir, GB Patent Application, No 9125978.8. (1991).
- ShafieiZarghani, A., Kashani-Bozorg, S. F., ZareiHanzaki, A., Ultrafine Grained 6082 Aluminum Alloy Fabricated by Friction Stir Processing, Journal of Materials Physics B. 22 [18&19] (2008) 2874-2878.
- Kwon, Y. J., Saito, N., Shigematsu, I., Friction Stir Process as a New Manufacturing Technique of UltrafineGrained aluminum Alloy, Materials Science Letter. 21 (2002) 1473–1476.
- Ma, Z. Y., Sharma, S. R., Mishra, R. S., Effect of Friction Stir Processing on the Microstructure of Cast A356 Aluminum, Materials Science and Engineering A. 433 (2006) 269–278.
- Ma, Z. Y., Mishra, R. S., Mahoney, M. W., Superplastic Deformation Behavior of Friction Stir Processed 7075Al Alloy, Acta Materialia. 50 (2006) 4419–4430.
- Hsu, C. J., Kao, P. W., Ho, N. J., Ultrafine-grained Al–Al2Cu Composite Produced in situ by Friction Stir Processing, Scripta Materialia. 53 (2005) 341– 345.
- Wang, W., Shi, Q. Y., Liu, P., Li, H. K., Li, T., A Novel Way to Produce Bulk SiCpReinforced Aluminum Metal Matrix Composites by Friction Stir Processing, Journal of Materials Processing Technology. 209 (2009) 2099–2103.
- Mishra, R. S., Ma, Z. Y., Charit, I., Friction Stir Welding and Processing, Materials Science and Engineering A. 341(2003) 307–310.
- Azizieh, M., Kokabi, A. H., Abachi, P., Effect of Rotational Speed and Probe Profile on Microstructure and Hardness of
AZ31/Al2O3NanocompositesFabricated by Friction Stir Processing, Materials and Design. 32 (2011) 2034–2041. - Zohoor,M., BesharatiGivi, M. K., Salami, P., Effect of Processing Parameters on Fabrication of Al–Mg/Cu Composites via Friction Stir Processing, Materials and Design. 39 (2012) 358– 365.
- Krajewski, A, D’Alessio, L., De Maria, G., Physiso-Chemical and Thermo physical Properties of Cubic Binary Carbides, Crystal Research and Technology. 33 (1998) 341–374.
- Zener, C. S., Grains, Phases and Inter- faces: An Interpretation of Micro- structure, Transactions of AIME. 175 (1948) 45- 48.
- Tomas, J., Adhesion of UltraFineParticles-energy Absorption at Contact, Chemical Engineering Science. 62 (2007) 5925–5939.
- Hamilton, C., Dymek, S., Blicharski, M., A Model of Material Flow During Friction Stir Welding, Materials Characterization, 2008, 59, 1206-1214.
- Heurtier, P., Jones, M. J., Desrayaud, C., Driver, J. H., Montheillet, F., Allehaux, D., Mechanical and Thermal Modelling of Friction Stir Welding, journal of Materials Processing Technology. 171 (2006) 348-357.
- C.I. Chang, C.J. Lee, J.C. Huang, Relationship Between Grain Size and Zener–Holloman Parameter
- During Friction Stir Processing in AZ31 Mg Alloys, Scripta Materialia. 51 (2004) 509–514.
- Chang, C. I., Wang, Y. N., Pei, H. R., Lee, C. J., Huang, J. C., On the Hardening of Friction Stir Processed Mg-AZ31 Based Composites with 5– 20% Nano-ZrO2 and Nano-SiO2 Particles, Materials Transaction. 47[12] (2006) 2942–2949.
- Lee, C., Huang, J., Hsieh, P., Mg Based NanoComposites Fabricated by Friction StirProcessing,Scripta Mater. 54 (2006) 1415–1420.
- Lloyd, D. J., Particle Reinforced Aluminum and Magnesium Matrix Composites, International Materials Review. 39 (1994) 1–24.