About weldability and welding of Al alloys: case study and problem solving

• Autorzy: Fracchia E. , Gobber F. , Rosso M.

Identyfikatory

DOI

10.5604/01.3001.0010.8036

• Języki publikacji: EN

Abstrakty

EN

Purpose: Among many disciplines within engineering, welding is probably one of the most inexact – rather more of an art than a science. As weldment is meant the complete joint comprising the weld metal, heat affected zones (HAZ) and the adjacent parent metal and should have the same properties as the parent metal. This paper aims provides a basic understanding of the metallurgical principles involved in how aluminium alloys achieve their strength and how welding can affect these properties. The most important and applied welding processes to Al alloys are here shortly introduced, as well as the preparation of parent metals prior to welding and good welding practice to avoid and/or keep under control defects and failures. Some case studies with possible failures will be introduced together with actions and suggestions to solve the observed problems. Design/methodology/approach: Two sheets of the EN AW 5454 (AlMg3Mn) alloy were weld with resistance welding process and after a mechanical processing of lamination was observed the presence of the defect. The microstructure of the defect as well as the welded part were evaluated with stereomicroscope (LEICA MS5), optical microscope (LEICA MEF4M), and with SEM analysis (LEO 1540 VP equipped with an energy dispersive X-ray spectroscope Oxford Link Pentafet). Findings: The well welded part was analysed with optical microscopy and electronic microscopy resulting with the attended mechanical properties. Micro-hardness indentations on the joint demonstrated the good mechanical properties of the joint while with the microscopic observations were identified the orientation and presence of precipitates typical of this alloy. In the defect, microscopically observations showed the presence of oxide inclusions. Research limitations/implications: There are a number of problems associated with the welding of aluminium and its alloys that make it difficult to achieve this ideal. The features and defects that may contribute to the loss of properties comprise the following: gas porosity, oxide inclusions and oxide filming, solidification (hot) cracking or hot tearing, reduced strength in the weld and HAZ, lack of fusion, reduced corrosion resistance and reduced electrical resistance. Originality/value: This case study illustrated clearly the importance of the cleaning on the surfaces to obtain a well welded joint ensuring the desired mechanical properties.

Słowa kluczowe

EN

heat affected zone; weldability; aluminium alloys

PL

strefa wpływu ciepła; spawalność; stopy aluminium

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2017
• Tom: Vol. 85, nr 2
• Strony: 67--74
• Opis fizyczny: Bibliogr. 5 poz., rys., tab.

Twórcy

autor

Fracchia E.

• Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Torino, Italy

autor

Gobber F.

• Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Torino, Italy

autor

Rosso M.

• Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129 Torino, Italy

Bibliografia

• [1] G. Mathers, The welding of aluminium and its alloys, Woohead Publishing, 22.
• [2] G. Çam, G. İpekoğlu, Recent developments in joining of aluminum alloys, The International Journal of Advanced Manufacturing Technology 91/5-8 (2017) 1851-1866, doi: 10.1007/s00170-016-9861-0.
• [3] M. Hakem, S. Lebaili, J. Miroud, A. Bentaleb, S.Toukali, Welding and characterization of 5083 aluminum alloy, Proceedings of the 21st International Conference on Metallurgy and Materials “Metal 2012”, Brno, Czech Republic, 2012.
• [4] S. Li, H. Dong, L. Shi, P. Li, F. Ye, Corrosion behavior and mechanical properties of Al-Zn-Mg aluminum alloy weld, Corrosion Science 123 (2017) 243-255, doi: 10/1016/j.corsci.2017.05.007.
• [5] AWS. A5.10 Specification for Bare Aluminum and Aluminum-Alloy Welding electrodes and Rods, 1999;1999:31.

Uwagi

PL

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).