Failure Investigation of Cold-Rolled ZnTiCu Alloy Fracture During Bending Under Ambient Temperature Conditions
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Bending ductility is an important quality parameter of the ZnTiCu rolled sheet for the fabrication of specially formed members in construction industry. Fabrication of such components is usually realized under severe loading conditions (i.e., high strain rate forming using manual tools or press brake machinery) and even sometimes under low temperature environment in the construction field, which is very often close to or less than 0 °C. Bending orientation is also an important parameter, since texture-sensitive Zn alloy cold-worked strip affects ductility performance in direction transverse to the rolling direction. A failure analysis process was implemented on a ZnTiCu bent sheet possessing cracks on outer bent areas. Light optical metallography, and scanning electron microscopy coupled with energy dispersive spectrometry, along with mechanical testing were the principal investigation techniques employed to evaluate the failure. The presence of pronounced elongated grain structure combined with coarse and continuous Ti-rich intermetallic phase, likely reduces the fracture resistance against the transverse stress field imposed by bending, stimulating, thus crack initiation and propagation.
KeywordsZnTiCu alloy Rolled sheet formability Bending fracture Failure analysis
The authors acknowledged Mr. A. Louvaris for his contribution to the experimental work.
- 1.BS EN 988 Zinc and Zinc Alloys: Specification for Rolled Flat Products for Building. (European Committee for Standardization (CEN), Brussels, 1997)Google Scholar
- 4.E.H. Rennhack, Redetermined zinc-rich portion of the Zn-Ti system. Trans. AIME 236, 941–942 (1966)Google Scholar
- 5.G.E. Dieter, Mechanical Metallurgy. SI Metric Edition (McGraw-Hill, New York, 1988)Google Scholar
- 6.W.F. Hosford, R.M. Caddell, Metal Forming: Mechanics and Metallurgy (Prentice Hall, Englewood Cliffs, 1983)Google Scholar
- 7.G. Pantazopoulos, A. Vazdirvanidis, Analysis of Bending Failure of a Zn-Alloy Sheet. 10th National Conference of Metallurgy (Varna, Bulgaria, 2007), pp. 28–31Google Scholar
- 8.J.A. Schey, Introduction to Manufacturing Processes, 2nd edn. (McGraw Hill, New York, 1987)Google Scholar