Effect of Cooling Rates on the Microstructure and Mechanical Property of La Modified Al7SiMg Alloys Processed by Gravity Die Casting and Semi-Solid Die Casting

Li, Longfei; Li, Daquan; Feng, Jian; Zhang, Yongzhong; Kang, Yonglin

doi:10.3390/met10040549

Cited by 6 publications

(3 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Secondly, the Si particle size has great influence on the mechanical property. When strengthening particles are dispersed evenly, the dislocation motion can be inhibited and the slip can be dispersed, thus the localized shear stress can be relieved and the yield strength can be increased [11,[49][50][51][52]. Therefore, the continuous network distribution of eutectic Si is another important factor that improves the strength of SLM Al-10Si-0.5Mg alloy.…”

Section: Strengthening Mechanismmentioning

confidence: 99%

A Comparative Study on the Microstructures and Mechanical Properties of Al-10Si-0.5Mg Alloys Prepared under Different Conditions

Guo

Sun

Huang

et al. 2022

Metals

View full text Add to dashboard Cite

Fabrication condition greatly influences the microstructures and properties of Al alloys. However, most of the available reports focus on a single fabrication technique, indicating there is still a lack of systematic comparisons among wider ranges of fabrication methods. In this paper, with conventional casting (via sand/Fe/Cu mold) and additive manufacturing (AM, via selective laser melting, SLM) methods, the effects of cooling rate (Ṫ) on the microstructures and mechanical properties of hypoeutectic Al-10Si-0.5Mg alloy are systematically investigated. The results show that with increasing cooling rate from sand-mold condition to SLM condition, the grain size (d) is continuously refined from ~3522 ± 668 μm to ~10 μm, and the grain morphology is gradually refined from coarse dendrites to a mixed grain structure composed of columnar plus fine grains (~10 μm). The eutectic Si particles are effectively refined from blocky shape under sand/Fe-mold conditions to needle-like under Cu-mold conditions, and finally to fine fibrous network under SLM condition. The tensile yield strength and elongation is greatly improved from 125 ± 5 MPa (sand-mold) to 262 ± 3 MPa (SLM) and from 0.8 ± 0.2% (sand-mold) to 4.0 ± 0.2% (SLM), respectively. The strengthening mechanism is discussed, which is mainly ascribed to the continuous refinement of grains and Si particles and an increase in super-saturation of Al matrix with increasing cooling rate.

show abstract

Section: Strengthening Mechanismmentioning

confidence: 99%

A Comparative Study on the Microstructures and Mechanical Properties of Al-10Si-0.5Mg Alloys Prepared under Different Conditions

Guo

Sun

Huang

et al. 2022

Metals

View full text Add to dashboard Cite

show abstract

“…During the solution treatment process, the precipitates in the as-cast structure of the Al-7.0Si-0.3Mg alloy dissolved, so that the Mg element was fully dissolved in the α-Al, which was well prepared for the aging treatment [15,16]. At the same time, the Si phase morphology in the alloy matrix significantly changed due to the high-temperature diffusion, which had a significant impact on the mechanical properties of the Al-7.0Si-0.3Mg alloy [17,18]. The solution temperature was determined at 525 • C. The solution time was set as 0h, 3 h, 6 h, 10 h, 12 h, and 15 h, respectively.…”

Section: Effect Of Solution Treatment On Low-temperature Mechanical P...mentioning

confidence: 99%

Effect of Heat Treatment on Mechanical Properties and Fracture Behavior of Al-7.0Si-0.3Mg Alloy at Low Temperature

Yang

Geng

et al. 2022

Crystals

View full text Add to dashboard Cite

In order to investigate the effect of heat treatment on the mechanical properties of the Al-7.0Si-0.3Mg alloy at 20−60 °C under different heat treatment processes, the tensile mechanical properties of Al-7.0Si-0.3Mg at low temperature after heat treatment were explored. The microstructure of Al-7.0Si-0.3Mg was observed by scanning electron microscopy (SEM) and transmission electron microscopy. The results show that the resistance of the dislocation movement in α-Al increased in the low-temperature condition, which is beneficial for the number of Si phase fractures that increase to enhance the tensile strength and weaken the elongation of the Al-7.0Si-0.3Mg alloy. After the solution treatment, the particle size of the Si phase reduced, while the morphology became rounded. In the early stage of aging, a GP region is generated inside the α-Al. With the prolonging of aging time, the acicular β″ phase is formed and then grows into rod-shaped β′. In the overaging stage, β′ eventually grows into flaky β. Due to the different linear expansion coefficients of the α-Al and the Mg2Si phase in the Al-7.0Si-0.3Mg alloy, the α-Al is squeezed by the Mg2Si phase under the effect of low-temperature shrinkage.

show abstract

“…Therefore, there have been a lot of studies on semi-solid forming of aluminum alloy. The current semi-solid forming technology for aluminum alloy is mostly focused on the cast aluminum alloys because the semi-solid slurry is easier to prepare [3][4][5]. Because the mechanical properties of cast aluminum alloys are relatively insufficient, wrought aluminum alloys with better performance have gradually become a research hotspot [6].…”

Section: Introductionmentioning

confidence: 99%

Microstructure and Wear Resistance of TiB2/7075 Composites Produced via Rheocasting

Gao

Yang

Gan

et al. 2020

Metals

View full text Add to dashboard Cite

In this study, TiB2/7075 aluminum matrix composites were prepared via in situ synthesis. It was found that TiB2 particles are mainly quadrate. Large TiB2 particles (1–2 μm) agglomerate at grain boundaries, but most of the particles are on the submicron scale. Adding 4.5 wt.% TiB2 particles effectively optimizes α-Al grains in the 7075 aluminum alloy. By combining in situ reinforcing particles with the self-stirring effect of a serpentuator, rheocasting of the 7075 aluminum alloy was achieved in a simple and economical way. The average grain size of the specimen after rheocasting and heat treatment was smaller than 33 μm, and the shape factors were greater than 0.85. The wear resistance of the 4.5 wt.% TiB2/7075 aluminum matrix composite that was prepared via rheocasting and gravity casting was tested with loads of 30, 60, 90, and 120 N at a friction speed of 0.15 m/s for a duration of 30 min. Because of the optimized microstructure and increased hardness, the wear resistance of the 4.5 wt.% TiB2/7075 aluminum matrix composite was significantly better than that of the 7075 aluminum alloy, and the wear resistance of the rheocast TiB2/7075 aluminum matrix composite was better than that of the gravity cast one.

show abstract

Effect of Cooling Rates on the Microstructure and Mechanical Property of La Modified Al7SiMg Alloys Processed by Gravity Die Casting and Semi-Solid Die Casting

Cited by 6 publications

References 22 publications

A Comparative Study on the Microstructures and Mechanical Properties of Al-10Si-0.5Mg Alloys Prepared under Different Conditions

A Comparative Study on the Microstructures and Mechanical Properties of Al-10Si-0.5Mg Alloys Prepared under Different Conditions

Effect of Heat Treatment on Mechanical Properties and Fracture Behavior of Al-7.0Si-0.3Mg Alloy at Low Temperature

Microstructure and Wear Resistance of TiB2/7075 Composites Produced via Rheocasting

Contact Info

Product

Resources

About