An investigation on primary Si refinement by Sr and Sb additions in a hypereutectic Al-Si alloy Reza Haghayeghi , Giulio Timelli Hypereutectic Al-Si alloys have got interests in many industrial applications such as automotive and wear-resistance environments. However, the hypereutectic Al-Si alloys have a few drawbacks. The acicular shape of eutectic Si acts as a…
An Investigation onWear Properties of A390 Alloy by Rare Alloying Elements Giulio Timelli, Reza Haghayeghi, Giulia Scampone and Alessandro De Mori Abstract Hypereutectic Al–Si alloys are good candidates for many applications including automotive industry and heavy wear environments. Among them, A390 is widely used for cylinder blocks, transmission pumps, and air compressor housings. Due to…
Nanoscale stacking fault-assisted room temperature plasticity in flash-sintered TiO2 Ceramic materials have been widely used for structural applications. However, most ceramics have rather limited plasticity at low temperatures and fracture well before the onset of plastic yielding. The brittle nature of ceramics arises from the lack of dislocation activity and the need for high stress…
A first-principles phase field method for quantitatively predicting multi-composition phase separation without thermodynamic empirical parameter. Nature Communications, 2019; 10 (1), 1 August Japanese researchers were able to accurately predict the microstructure of Nickel-Aluminum (Ni-Al) alloys that are commonly used in the design of jet engine turbine parts. This procedure predicts the microstructure of alloys based…
Effect of pressure cycles and thermal conditions on the reliability of a high-pressure diecast Al alloy heating radiator Giulio Timelli, Alessandro De Mori, Reza Haghayeghi The fatigue reliability of a diecast AlSi11Cu2(Fe) alloy radiator has been investigated at different pressure amplitudes and thermal exposure. Based on failure mode analysis, two failure mechanisms are observed…
Reliability of a high-pressure die cast Al alloy radiator Giulio Timelli, Alessandro De Mori, Reza Haghayeghi The resistance to pressure of a diecast AlSi11Cu2(Fe) alloy radiator has been studied at various holding temperatures. A recently developed method to seal the bottom opening of the radiator element has been presented and its reliability has been…
Microstructural refinement of 7449 Al alloy through liquid shearing Haghayeghi. L. Nastac, “Microstructural refinement of 7449 Al alloy through liquid shearing”, Materials letters, Vol.65, 2011, PP. 3230-3233. Applying mechanical shearing by melt conditioner machine at above liquidus temperature was carried out. The experimental results show fine and uniform structure can be acquired across…
Microstructural Evolution of AA7449 Refined by Intensive shearing Haghayeghi, “Microstructural Evolution of AA7449 Refined by Intensive shearing”, Metals and Materials International, Vol.18, 2012, PP.777-782. Many aerospace alloys are sensitive to their composition thus cannot be chemically grain refined. In addition, only 1% grain refiners can act as nuclei for refining the structure. In…
Effect of UT argon degassing on dissolved hydrogen in Al alloy Haghayeghi, H. Bahai, P. Kaoranos, “Effect of UT argon degassing on dissolved hydrogen in Al alloy”, Materials Letters, Vol.82, 2012, PP.230-232. Ultrasonic degassing has been shown to be a reasonably efficient way of degassing a melt. Similarly, vacuum degassing has also been…
Physical and chemical refinement of aerospace Al alloys Reza Haghayeghi , P. Kapranos, “Physical and chemical refinement of aerospace Al alloys”, Materials Letters, Vol.95, 2013, PP.121-124 Conventional grain refinement is performed through the addition of chemical refiners. However, this article proposes physical refinement as an alternative method for producing fine grain size….