Self-healing alloys are promising materials that can decrease the consequences of accidents. To detect crack formation in a material is simple task that can be performed by e.g., sonic or ultrasound detection, but it is not always possible to immediately replace the damaged parts. In this situation, it is very advantageous to have the chance to heal the crack during operation, which can be done e.g., by annealing. In this paper, self-healing behavior was proven by TEM (Transmission electron microscope) observation of crack healing after annealing. The crack was observed in the rapidly solidified Al-30Ag alloy with non-equilibrium phase composition formed by a minor amount of Ag₂Al and a supersaturated solid solution of Ag in an fcc-Al matrix (fcc = face centered cubic). After annealing at 450 °C, equilibrium phase composition was obtained by forming a higher amount of Ag₂Al. This phase transformation did not allow the crack to be healed. Subsequent annealing at 550 °C caused recrystallization to a supersaturated solid solution of Ag in fcc-Al, followed by a return to the mixture of fcc-Al and Ag₂Al by cooling, and this process was accompanied by the closing of the crack. This observation proved the self-healing possibilities of the Ag₂Al phase. Practical application of this self-healing behavior could be achieved through the dispersion of fine Ag₂Al particles in a structural material, which will enrich the material with self-healing properties.

Department of Inorganic Chemistry University of Chemistry and Technology Prague Technická 5 166 28 Prague 6 Czech Republic

Department of Metals and Corrosion Engineering University of Chemistry and Technology Prague Technická 5 166 28 Prague 6 Czech Republic

Zobrazit více v PubMed

Průša F., Báhová M., Vojtěch D., Kučera V., Bernatíková A., Kubatík T.F., Michalcová A. High-Strength Ultra-Fine-Grained hypereutectic Al-Si-Fe-X (X = Cr, Mn) alloys prepared by Short-Term mechanical alloying and spark plasma sintering. Materials. 2016;9:973. doi: 10.3390/ma9120973. PubMed DOI PMC

Školáková A., Novák P., Mejzlíková L., Průša F., Salvetr P., Vojtěch D. Structure and mechanical properties of Al-Cu-Fe-X alloys with excellent thermal stability. Materials. 2017;10:1269. doi: 10.3390/ma10111269. PubMed DOI PMC

Michalcová A., Vojtěch D., Novák P., Šittner P., Pilch J., Drahokoupil J., Kolařík K. Structure and mechanical properties of an AlCr6Fe2Ti1 alloy produced by rapid solidification powder metallurgy metod et al. Int. J. Mater. Res. 2010;101:307–309. doi: 10.3139/146.110274. DOI

Van Tittelboom K., De Belie N. Self-Healing in cementitious materials—A review. Materials. 2013;6:2182–2217. doi: 10.3390/ma6062182. PubMed DOI PMC

Shi S.-C., Huang T.-F. Self-Healing Materials for Ecotribology. Materials. 2017;10:91. doi: 10.3390/ma10010091. PubMed DOI PMC

Gupta R.K., Mirza F., Khan M.U.F., Esquivel J. Aluminum containing Na2CrO4: Inhibitor release on demand. Mater. Lett. 2017;205:194–197. doi: 10.1016/j.matlet.2017.06.080. DOI

Fan Z., Wang K., Dong X., Wang R., Duan W., Mei X., Wang W., Zhang S., Xu C. Enhanced cyclic oxidation resistance through the self-healing of segmented cracks using nano-Al2O3/Ni-20 wt%Al particles in laser re-melted thermal barrier coatings. Mater. Lett. 2017;201:156–160. doi: 10.1016/j.matlet.2017.04.116. DOI

Du K., Guo X., Guo Q., Wang F., Tian Y. A monolayer PEO coating on 2024 Al alloy by transient self-feedback control mode. Mater. Lett. 2013;91:45–49. doi: 10.1016/j.matlet.2012.09.055. DOI

Zhang Y., Li Y., Ren Y., Wang H., Chen F. Double-doped LDH films on aluminum alloys for active protection. Mater. Lett. 2017;192:33–35. doi: 10.1016/j.matlet.2017.01.038. DOI

Rohatgi P.K. Al-shape memory alloy self-healing metal matrix composite. Mater. Sci. Eng. A. 2014;619:73–76. doi: 10.1016/j.msea.2014.09.050. PubMed DOI PMC

Grabowski B., Cem T. Advances in Polymer Science. Springer; New York, NY, USA: 2015. Self-Healing Metals.

Li W., Jiang Z., Yang Z. Extension and possibility of debonding in encapsulation-based self-healing materials. Materials. 2017;10:589. doi: 10.3390/ma10060589. PubMed DOI PMC

Kim D.-M., Cho Y.-J., Choi J.-Y., Kim B.-J., Jin S.-W., Chung C.-M. Low-Temperature Self-Healing of a Microcapsule-Type Protective Coating. Materials. 2017;10:1079–1093. PubMed PMC

Hautakangas S., Schut H., van Dijk N.H., Rivera Diaz del Castillo P.E.J., van der Zwaak S. Self-healing of deformation damage in underaged Al–Cu–Mg alloys. Scr. Mater. 2008;58:719–722. doi: 10.1016/j.scriptamat.2007.11.039. DOI

Alaneme K.K., Bodunrin M.O. Self-healing using metallic material systems—A review. Appl. Mater. Today. 2017;6:9–15. doi: 10.1016/j.apmt.2016.11.002. DOI

Sheng X., Lei Q., Xiao Z., Wang M. Precipitation Behavior and Quenching Sensitivity of a Spray Deposited Al-Zn-Mg-Cu-Zr Alloy. Materials. 2017;10:1100. doi: 10.3390/ma10091100. PubMed DOI PMC

Zarkevic N.A., Johnson D.D. Predicted hcp Ag-Al metastable phase diagram, equilibrium ground states, and precipitate structure. Phys. Rev. B. 2013;67:1–8. doi: 10.1103/PhysRevB.67.064104. DOI

Prashanth K.G., Scrudino S., Chaubey A.K., Lober L., Wang P., Attar H., Schimanski F.P., Pyczak F., Eckert J. Processing of Al-12Si-TNM composites by selective laser melting and evaluation of compressive and wear properties. J. Mater. Res. 2016;31:55–65. doi: 10.1557/jmr.2015.326. DOI

Prashanth K.G., Shakur Shahabi H., Attar H., Srivastava V.C., Ellendt N., Uhlenwinkel V., Eckert J., Scrudino S. Production of high strength Al85Nd8Ni5Co2 alloy by selective laser melting. Addit. Manuf. 2015;6:1–5. doi: 10.1016/j.addma.2015.01.001. DOI

Danesh Manesh H., Mashreghi A., Ehtemam Haghighi S., Khajeh A. Investigation of cold pressure welding of aluminum powder to internal surface of aluminum tube. Mater. Des. 2009;30:723–726. doi: 10.1016/j.matdes.2008.05.014. DOI

Dixmier J., Guinier A. Production of New Phases by Ultra-Rapid Quenching of Liquid Alloys. Mem. Sci. Rev. Met. 1967;64:53–58.

Tash M.M., Mahmoud E.R.I. Development of in-Situ Al-Si/CuAl2 Metal Matrix Composites: Microstructure, Hardness, and Wear Behavior. Materials. 2016;9:442. doi: 10.3390/ma9060442. PubMed DOI PMC

Rapidly Solidified Aluminium Alloy Composite with Nickel Prepared by Powder Metallurgy: Microstructure and Self-Healing Behaviour