| 1. |
- Ceschini, Lorella, et al.
(author)
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High temperature tensile behaviour of the A354 aluminum alloy
- 2014
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In: Materials Science Forum. ; 794-796, s. 443-448
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Journal article (peer-reviewed)abstract
- The high temperature tensile behaviour of the A354 casting aluminum alloy was investigated also evaluating the influence of secondary dendrite arm spacing (SDAS). Cast specimens were produced through a gradient solidification equipment, obtaining two different classes of SDAS, namely 20-25 µm (fine microstructure) and 40-50 µm (coarse microstructure). After hot isostatic pressing and T6 heat treatment, the samples underwent mechanical characterization both at room and high temperature (200 °C). Results of tensile tests and hardness measurements were related to the microstructural features and fractographic characterization, in order to investigate the effect of microstructure and high temperature exposure on the mechanical behaviour of the alloy.
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| 2. |
- Ceschini, L., et al.
(author)
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Room and high temperature fatigue behaviour of the A354 and C355 (Al-Si-Cu-Mg) alloys : Role of microstructure and heat treatment
- 2016
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In: Materials Science & Engineering. - : Elsevier. - 0921-5093 .- 1873-4936. ; 653, s. 129-138
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Journal article (peer-reviewed)abstract
- Al-Si-Mg alloys are widely used in the automotive industry for the production of engine components. Due to the new stringent emissions standards, these components undergo highertemperatures than in the past; as a result, alloys with higher thermal stability, such as the Al-Si-Cu-Mg, are currently under investigation.The present paper aims at widening the knowledge on the relationship between room temperature (RT) and high temperature fatigue behaviour of A354 and C355 alloys and their microstructural features, in particular, secondary dendrite arm spacing (SDAS) and intermetallic compounds. Samples for fatigue characterization were hot isostatic pressed, aiming to avoid the effect of solidification defects.The results of microstructural analyses and rotating bending fatigue tests highlighted that (i) SDAS influences room temperature fatigue behaviour of the peak-aged A354 and C355 alloys, while its effect on the overaged alloys at high temperature is negligible; (ii) fatigue cracks nucleated mostly from large intermetallic compounds; (iii) at room temperature, C355 alloy is characterized by higher fatigue strength (151 and 135. MPa for fine and coarse SDAS, respectively) in comparison to A354 alloy (133 and 113. MPa); after overaging and testing at high temperature, the behaviour of the two alloys is comparable. A good correlation between ultimate tensile strength and fatigue resistance was found, independent of microstructure and aging condition.
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| 3. |
- Di Egidio, G., et al.
(author)
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Dry sliding behavior of AlSi10Mg alloy produced by Laser-based Powder Bed Fusion : influence of heat treatment and microstructure
- 2023
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In: Wear. - : Elsevier. - 0043-1648 .- 1873-2577. ; 516-517
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Journal article (peer-reviewed)abstract
- The L-PBF AlSi10Mg alloy is widely used in the production of structural parts in the transportation sector. However, the high stresses caused by the severe operating conditions require an optimal combination of mechanical and tribological properties. This paper reports on the effect of optimized T5 heat treatment (direct artificial aging: 4 h at 160 °C) and novel T6 heat treatment (rapid solution: 10 min at 510 °C, followed by artificial aging: 6 h at 160 °C) on the tribological behavior of the L-PBF AlSi10Mg alloy. Dry sliding tests (ball-on-disk) were carried out using AlSi10Mg samples as rotating disks against an Al2O3 stationary ball. The optimized T5 led to the formation of a stable protective oxide layer well adherent on the worn surface, increasing the wear resistance of the alloy. In addition, the novel T6 improved wear resistance compared to conventional T6 due to microstructural refinement induced by shorter solutionizing. The sub-surface analysis of the wear tracks highlighted the higher cohesion between the more homogeneous and finer Si particles and the α-Al matrix, as well as the improved load-bearing support compared to the coarser microstructure induced by conventional T6. Therefore, the new T6 could be the optimal solution for high-performance components.
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