Production of cellular A2011 alloy from semi-solid state

• Autorzy: Robert M. H. , Delbin D.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The work investigates a new method to produce cellular A2011 alloy and analyses the influence of processing parameters on the quality of the product. Design/methodology/approach: The proposed process involves pressing the alloy in the thixotropic semi solid state into a layer of space holder particles, which are removed after the forming operation. It is investigated the influence of the thixoforming temperature and the size of space holder particles, in the ability of penetration of the slurry in the porous pre-form as well as the structure of the obtained porous material. Products were analyzed by tomography and metallographic techniques. Findings: The proposed process showed to be able to produce acceptable porous material in a simple and low cost technique; the cellular material produced was characterized as sponge, as presented open and interconnected porosity. The quality of the product depends rather on the processing temperature than on the size of space holder particles. Low liquid fraction in the thixotropic slurry can lead to incomplete infiltration and deformation of the pre-form. In the analyzed conditions influence of the size of space holder particles could be observed neither in the processing ability nor in the quality of the product. Density of produced porous material increases as processing temperature increases, due to the increase of cells walls thickness. Research limitations/implications: The investigated process is suitable only for alloys with a significant solidification range. Practical implications: The new method to produce cellular metals can represent energy savings and is highly operational when compared to conventional methods based on liquid infiltration, since lower temperatures are involved and no need of liquid handling is required. Originality/value: The process proposed is a new one; no techniques based on thixoforming of the alloy into porous pre-forms are known so far.

Słowa kluczowe

EN

metallic alloy; cellular material; metallic sponges; thixoforming

PL

stop metaliczny; materiał komórkowy; gąbczaste materiały metaliczne; formowanie tiksotropowe

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2006
• Tom: Vol. 17, nr 1-2
• Strony: 137--140
• Opis fizyczny: Bibliogr. 7 poz., rys., wykr.

Twórcy

autor

Robert M. H.

• Faculty of Mechanical Engineering, State University of Campinas, CEP 13083-970, Campinas, SP, Brazil

autor

Delbin D.

• Faculty of Mechanical Engineering, State University of Campinas, CEP 13083-970, Campinas, SP, Brazil

Bibliografia

• [1] J. Banhart, Al foams: on the road for real application, MRS Bulletin, 2003, 290-293.
• [2] J. Banhart, Manufacturing routes for metallic foams, JOM 2000, 22-27.
• [3] C. San Marchi, A. Mortensen, Infiltration and replication process for producing metal sponges, Handbook of Cellular Metals, Wiley VCH, Weinheim, 2002, 43-55.
• [4] A. E Markaki, T. W. Clyne, The effect of cell wall microstructure on deformation and fracture of aluminium based foams. Acta Materiallia, 49, 2001, 1677-1686.
• [5] M. H. Robert, Partial melting as an efficient method to produce rheocast alloy slurries, Transactions of the Japan Foundrymen’s Society, vol. 12, 1993, 45-51.
• [6] M. M. Rovira, M. H. Robert, Effect of the thixoforging operation on the microstructure of AA2011 alloy, Proceedings of the 10th International Scientific Conference Achievements in Mechanical and Materials Engineering, Zakopane, 2001, 357-360.
• [7] E. J. Zoqui, M. H. Robert, Structural modifications in rheocast Al-Cu alloys by heat treatment and implications on mechanical properties, Journal of Materials Processing Technology, v.78, 1998, 198-203.