The role of transition metal additions on the ambient and elevated temperature properties of Al-Si alloys

Zamani, Mohammadreza; Ceschini, Lorella; Seifeddine, Salem

doi:10.1016/j.msea.2017.03.084

Cited by 58 publications

(50 citation statements)

References 47 publications

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“…The results show a rapid decrease in hardness during the first 10 h for both alloys. These results agree with the observations by Zamani et al 4 The alloy with combined Co and Ni addition has a hardness value about 12% higher than the base alloy. This could be because of the formation of thermally stable Co and Ni intermetallics in the Al-7Si-Co-Ni alloy.…”

Section: Mechanical Properties: Hardnesssupporting

confidence: 93%

“…3 However, the use of cast Al-Si alloys at temperatures exceeding 200°C is challenging because of the significant reduction in the mechanical properties at elevated temperature. 2,4 Therefore, researchers have focused significant efforts into improving the mechanical properties of Al-Si alloys at elevated temperatures through tailoring microstructure and alloy composition, and addition of transition elements has been shown to promote thermally stable phases. 2,[4][5][6][7] Both Co and Ni have high melting points and are well known as superalloys for high-temperature applications.…”

Section: Introductionmentioning

confidence: 99%

“…2,4 Therefore, researchers have focused significant efforts into improving the mechanical properties of Al-Si alloys at elevated temperatures through tailoring microstructure and alloy composition, and addition of transition elements has been shown to promote thermally stable phases. 2,[4][5][6][7] Both Co and Ni have high melting points and are well known as superalloys for high-temperature applications. 8,9 Limited studies have been carried out on the combined effects of Co and Ni in Al-Si alloys.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Co and Ni Addition on the Microstructure and Mechanical Properties at Room and Elevated Temperature of an Al–7%Si Alloy

2017

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Increasing environmental demands are forcing the automotive industry to reduce vehicle emissions by producing more light-weight and fuel efficient vehicles. Al-Si alloys are commonly used in automotive applications because of excellent castability, high thermal conductivity, good wear properties and high strength-to-weight ratio. However, most of the aluminium alloys on the market exhibit significantly reduced strength at temperatures above 200°C. This paper presents results of a study of the effects of Co and Ni in a hypoeutectic Al-Si alloy on microstructure and mechanical properties at room and elevated temperature. Tensile test specimens with microstructures comparable to those obtained in high-pressure die casting, i.e. SDAS * 10 lm, were produced by directional solidification in a Bridgman furnace. The results show an improvement in tensile properties up to 230°C.

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Section: Mechanical Properties: Hardnesssupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Effect of Co and Ni Addition on the Microstructure and Mechanical Properties at Room and Elevated Temperature of an Al–7%Si Alloy

2017

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“…The drawback of Al-based composites lies in the high-temperature performance since the Al matrix suffers from softening during thermal exposure. Alloying elements like copper (Cu) and nickel (Ni) are specifically added to maintain good mechanical properties at high temperatures [ 10 , 11 , 12 , 13 ]. These elements form intermetallic compounds that are thermally stable and can withstand load bearing during temperature rise.…”

Section: Introductionmentioning

confidence: 99%

On the Hardness and Elastic Modulus of Phases in SiC-Reinforced Al Composite: Role of La and Ce Addition

Lattanzi

Jarfors

et al. 2021

Materials

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The use of silicon carbide particles (SiCp) as reinforcement in aluminium (Al)-based composites (Al/SiCp) can offer high hardness and high stiffness. The rare-earth elements like lanthanum (La) and cerium (Ce) and transition metals like nickel (Ni) and copper (Cu) were added into the matrix to form intermetallic phases; this is one way to improve the mechanical property of the composite at elevated temperatures. The α-Al15(Fe,Mn)3Si2, Al20(La,Ce)Ti2, and Al11(La,Ce)3, π-Al8FeMg3Si6 phases are formed. Nanoindentation was employed to measure the hardness and elastic modulus of the phases formed in the composite alloys. The rule of mixture was used to predict the modulus of the matrix alloys. The Halpin–Tsai model was applied to calculate the elastic modulus of the particle-reinforced composites. The transition metals (Ni and Cu) and rare-earth elements (La and Ce) determined a 5–15% increase of the elastic modulus of the matrix alloy. The SiC particles increased the elastic modulus of the matrix alloy by 10–15% in composite materials.

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“…At high temperatures, the alloy's precipitates such as β'' and θ´ which maintain the alloy strength at room temperature are usually coarsened or dissolved. As a result, the lack of strengthening phases leads to the considerable decline of alloy performance that limits their practical applications in engine blocks, cylinder heads, or heat shields [3][4][5][6][7]. Although higher Cu content improves the mechanical properties via forming a higher fraction of Al2Cu phase, the concentrations of Si and Cu in the industrial Al-Si based alloys have reached their limits because the addition of Cu increases corrosively and shrinkage porosities [8].…”

Section: Introductionmentioning

confidence: 99%

Nanoscale Zr-containing precipitates; a solution for significant improvement of high-temperature strength in Al-Si-Cu-Mg alloys

Rahimian

Amirkhanlou

Blake

et al. 2018

Materials Science and Engineering: A

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This work aims to reveal the valuable role of Zr in cast Al-Si-Cu-Mg alloys utilised at elevated temperatures. The Al7Si2Cu0.2Zr alloy, subjected to well-tuned heat treatment process, was benchmarked against the conventional Al7Si0.5Cu alloy. Microstructural investigation showed that the main strengthening phases in the Al7Si2Cu0.2Zr alloy are θ´, Q´, Al-Si-Cu-Zr and Al-Si-Zr precipitates. Two Zr-containing precipitates (Al-Si-Cu-Zr and Al-Si-Zr) with the size of 80-200 nm are formed during solutionising at530 °C, which can be considered as the first ageing step. Other two Cu-containing precipitates (θ´and Q´) at the size of 20 nm are formed during ageing (170 °C). Nano-sized Zr-containing precipitates are mostly exhibited elliptical morphology with coherent/semi-coherent interfaces with the α-Al matrix, making them more stable at elevated temperatures. As a result, the yield strength is improved at room temperature from 261 to 291 MPa, and the ultimate tensile strength (UTS) is improved from 282 to 335 MPa for the Al7Si2Cu0.2Zr alloy, compared with the Al7Si0.5Cu alloy. Moreover, the mechanical properties are significantly improved at elevated temperatures. The yield strength and UTS at 200 °C are 177 and 186 MPa, respectively, for the Al7Si0.5Cu alloy. But these are224 and 246 MPa, respectively, for the Al7Si2Cu0.2Zr 2 alloy. The improvement of mechanical properties at elevated temperatures is mainly attributed to the refined microstructure and the precipitation of strengthening phases containing slow-diffused Zr element to retard the precipitation coarsening. Furthermore, the addition of Cu changes the precipitates from θ´ and β´´ in the Al7Si0.5Cu alloy to θ´ and Q´ in the Al7Si2Cu0.2Zr alloy which, in turn, induce a complementary effect on the improvement of mechanical properties.

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The role of transition metal additions on the ambient and elevated temperature properties of Al-Si alloys

Cited by 58 publications

References 47 publications

Effect of Co and Ni Addition on the Microstructure and Mechanical Properties at Room and Elevated Temperature of an Al–7%Si Alloy

Effect of Co and Ni Addition on the Microstructure and Mechanical Properties at Room and Elevated Temperature of an Al–7%Si Alloy

On the Hardness and Elastic Modulus of Phases in SiC-Reinforced Al Composite: Role of La and Ce Addition

Nanoscale Zr-containing precipitates; a solution for significant improvement of high-temperature strength in Al-Si-Cu-Mg alloys

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