Practical aspects of discontinuous precipitation and dissolution

• Published in: Materials chemistry and physics Vol. 80; no. 2; pp. 476 - 481
• Main Authors: Tałach-Dumańska, Marta, Zięba, Paweł, Pawłowski, Andrzej, Wojewoda, Joanna, Gust, Wolfgang
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 26.05.2003; Elsevier
• Subjects: Applied sciences; Continuous dissolution; Cross-disciplinary physics: materials science; rheology; Discontinuous precipitation; Exact sciences and technology; Grain refinement; Materials science; Metals. Metallurgy; Physics; Solid solution hardening, precipitation hardening, and dispersion hardening; aging; Solid solution, precipitation, and dispersion hardening; aging; Strengthening; Treatment of materials and its effects on microstructure and properties; Discontinuous precipitation; Strengthening; Continuous dissolution; Grain refinement; Binary alloys; Tin alloys; Precipitation; Aluminium base alloys; Transmission electron microscopy; Grain refining; Experimental study; Microstructure; Dissolution; Heat treatments
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/S0254-0584(02)00550-3

A method of grain refinement which does not require plastic deformation is discussed. The refinement is obtained by a carefully designed thermal treatment in which the discontinuous precipitation (DP) reaction is followed by a dissolution process. Two different mechanisms of refinement were identified based on the investigations performed on Al–22at.% Zn and Ni–4at.% Sn alloys. The first one is associated with holding the orientation relationship of the former DP process. Such a behaviour was observed in the Al–22at.% Zn alloy in which the grains are refined by a factor of 7–8. If the small grains are created via recrystallisation within the area previously covered by a DP cell, like in Ni–4at.% Sn alloy, a refinement factor of 40 or even more can be obtained.