scholarly journals INVESTIGATION OF THE INFLUENCE OF DIFFERENT MODIFIERS ON THE EUTECTIC SI IN THE COMPOSITION OF ALSI18 ALLOY

2021 ◽  
Vol 3 ◽  
pp. 261-265
Author(s):  
Ivan Panov ◽  
Boyan Dochev ◽  
Valentin Manolov ◽  
Angel Velikov ◽  
Vanya Dyakova
Keyword(s):  
Eutectic Silicon ◽  
Microstructural Analysis ◽  
Primary Silicon ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Size And Shape ◽  
Silicon Crystals ◽  
Different Types ◽  
Eutectic Si ◽  
Shape And Size

The structure of hypereutectic aluminum-silicon alloys consists of primary silicon crystals arranged in a eutectic matrix. In the present work the influence of different types of modifiers on the size and shape of the silicon crystals in the composition of the eutectic of the AlSi18 alloy has been studied. The classic for this type of alloys modifier (phosphorus), as well as the nanomodifiers SiC and nanodiamonds (ND) have been used. The results of the microstructural analysis show that the three modifiers used affect differently the shape and size of the eutectic silicon of the investigated alloy.

scholarly journals INVESTIGATION OF THE INFLUENCE OF THE MODIFIERS P, SR, TI AND COMBINATIONS OF THEM ON THE STRUCTURE AND MECHANICAL PROPERTIES OF ALSI25 ALLOY

2021 ◽  
Vol 3 ◽  
pp. 256-260
Author(s):  
Ivan Panov ◽  
Boyan Dochev ◽  
Desislava Dimova
Keyword(s):  
Mechanical Properties ◽  
Primary Silicon ◽  
Mechanical Tests ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Size And Shape ◽  
Silicon Crystals ◽  
Positive Effect ◽  
Aluminum Silicon

The most commonly used elements to modify primary silicon crystals in the structure of hypereutectic aluminum-silicon alloys are phosphorus and sulfur. Phosphorus has been shown to have the highest coefficient of modification with respect to the primary silicon and is therefore a preferred modifier. There are also data on the positive effect of the modifiers Sb, Sr, Ti, and B on the silicon crystals in the structure of this type of alloys. The influence of the modifiers phosphorus, strontium, titanium and combinations of them on the size and shape of both the primary silicon crystals and the silicon crystals in the composition of the eutectic of the AlSi25 alloy has been studied in this work. Mechanical tests have been performed to determine both the strength and the plastic parameters of the investigated alloy (in unmodified and modified state). The classic for this type of alloys modifier - phosphorus - has been introduced into the melt by the ligature CuP10. Strontium has been introduced by the ligature AlSr10, and titanium - by the ligature AlTi5B1, the two ligatures in the form of rods. The investigated alloy has also been modified by combinations of the used modifiers: phosphorus and strontium, phosphorus and titanium.The influence of the used modifiers on the structure and mechanical properties of AlSi25 alloy has been discussed.

Growth of eutectic silicon from primary silicon crystals in aluminium-silicon alloys

1997 ◽  
Vol 36 (1) ◽  
pp. 47-54 ◽  
Author(s):  
A.J. Criado ◽  
J.A. Martínez ◽  
R. Calabrés
Keyword(s):  
Eutectic Silicon ◽  
Primary Silicon ◽  
Silicon Alloys ◽  
Silicon Crystals

scholarly journals Simultaneous Refinement of Primary Si and Modification of Eutectic Si in A390 Alloy Assisting by Sr-Modifier and Serpentine Pouring Channel Process

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3109 ◽  
Author(s):  
Pengyu Yan ◽  
Weimin Mao ◽  
Jing Fan ◽  
Bingkun Wang
Keyword(s):  
Eutectic Silicon ◽  
Primary Silicon ◽  
Interface Energy ◽  
Nucleation Site ◽  
Nucleation And Growth ◽  
Dominant Factor ◽  
Channel Process ◽  
Primary Si ◽  
Eutectic Si ◽  
A390 Alloy

In this study, A390 alloy was prepared using the combined process of a water-cooled copper serpentine pouring channel (SPC) and strontium (Sr) modifier, in order to simultaneously refine primary silicon (Si) and modify eutectic silicon (Si). The nucleation and growth mechanisms of the Si phase were discussed by morphology analysis and non-isothermal analytical kinetics. The results indicate that the size of primary Si is refined to 25.2–28.5 µm and the morphology of eutectic Si is modified from acicular into fibrous. The serpentine pouring channel process stimulates primary Si nucleation due to chilling effect and has no influence on eutectic Si nucleation. Impacts of Sr-modifier on primary and eutectic Si are similar, including three aspects: (1) poisoning of the nucleation site; (2) decreasing the interface energy between Si phase and liquid; (3) raising the activation energy for diffusion across solid-liquid interface. The content of Sr determines which one of the three aspects mentioned above is the dominant factor to promote or restrain the nucleation and growth of the primary and eutectic Si in hypereutectic Al-Si alloy.

scholarly journals Refinement of Primary Silicon Crystals by Novel P-Doped γ-Al2O3 Particles in Solidification of Hypereutectic Al-Si Alloys

2016 ◽  
Vol 877 ◽  
pp. 550-557 ◽  
Author(s):  
Kawther Al-Helal ◽  
Ian Stone ◽  
Zhong Yun Fan
Keyword(s):  
Particle Size ◽  
Size Range ◽  
Average Particle Size ◽  
Primary Silicon ◽  
Average Particle ◽  
Commercial Purity ◽  
Particle Size Range ◽  
Silicon Crystals ◽  
Primary Si ◽  
Eutectic Si

P-doped γ-Al2O3 was found to be a potent substrate to nucleate primary silicon whilst good modification of the eutectic matrix is retained during solidification of hypereutectic Al-Si alloys. On using P-doped γ-Al2O3 could be a perfect and clean source of P without additional impurities. The optical micrographs show that the morphologies of primary silicon crystals in solidification of Al-18Si alloy are changed from irregular coarse morphologies to fine regular particles. The average particle size of primary Si decreased from 52 μm to 25 μm and 22 μm in adding P-doped α-Al2O3 and P-doped γ-Al2O3 respectively. It was clear that P-doped γ-Al2O3 led to good refinement of primary Si and the modification effect on eutectic Si was retained in solidification of commercial purity Al-18Si alloy. Adding P-doped γ-Al2O3 give a good primary Si refinement to Al-18Si alloy if compared with the addition of P and using finer P doped γ-Al2O3 powder give narrower particle size range similar to that of adding P.

REYNOLDS 390 and A390

Alloy Digest ◽  
1971 ◽  
Vol 20 (8) ◽  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
High Hardness ◽  
Heat Treating ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Temperature Performance

Abstract REYNOLDS 390 and A390 are hypereutectic aluminum-silicon alloys having excellent wear resistance coupled with good mechanical properties, high hardness, and low coefficients of expansion. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, and machining. Filing Code: Al-203. Producer or source: Reynolds Metals Company.

ALUMINUM 713.0

Alloy Digest ◽  
1985 ◽  
Vol 34 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Room Temperature ◽  
High Strength ◽  
Heat Treating ◽  
Good Combination ◽  
Casting Alloy ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Permanent Mold Castings ◽  
Aluminum Base

Abstract ALUMINUM 713.0 is an aluminum-base casting alloy that ages at room temperature to provide high-strength sand and permanent-mold castings. It has a good combination of mechanical properties and its corrosion resistance is equivalent to that of the aluminum-silicon alloys. It is dimensionally stable. Among its many uses are housings, machinery parts, fittings, lever arms and brackets. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-263. Producer or source: Various aluminum companies.

scholarly journals A Spatiotemporal Statistical Method of Ship Domain in the Inland Waters Driven by Trajectory Data

2021 ◽  
Vol 9 (4) ◽  
pp. 410
Author(s):  
Fan Zhang ◽  
Xin Peng ◽  
Liang Huang ◽  
Man Zhu ◽  
Yuanqiao Wen ◽  
...  
Keyword(s):  
Statistical Method ◽  
Yangtze River ◽  
Domain Size ◽  
Inland Waters ◽  
The Yangtze River ◽  
Trajectory Data ◽  
Different Types ◽  
Dry Seasons ◽  
Ship Collision ◽  
Shape And Size

In this study, a method for dynamically establishing ship domain in inland waters is proposed to help make decisions about ship collision avoidance. The surrounding waters of the target ship are divided to grids and then calculating the grid densities of ships in each moment to determine the shape and size of ship domain of different types of ships. At last, based on the spatiotemporal statistical method, the characteristics of ship domains of different types of ship in different navigational environments were analyzed. The proposed method is applied to establish ship domains of different types of ship in Wuhan section of the Yangtze River in January, February, July, and August in 2014. The results show that the size of ship domain increases as the ship size increases in each month. The domain size is significantly influenced by the water level, and the ship domain size in dry seasons is larger than in the wet seasons of inland waters.

scholarly journals Effect of primary silicon crystals on the fluidity of eutectic and hypereutectic Al-Si alloys in lost foam casting

2021 ◽  
Author(s):  
Shailesh Kamble
Keyword(s):  
Process Parameters ◽  
Metal Flow ◽  
Primary Silicon ◽  
Lost Foam Casting ◽  
Minor Role ◽  
Automotive Components ◽  
Silicon Crystals ◽  
A Minor ◽  
Lost Foam

The hypereutectic Aluminum-Silicon (Al-Si) Alloys are gaining impetus in the automotive components, mainly due to their wear resistance. This property in these alloys is derived from the primary silicon crystals. However, there are unique metal flow and mold filling problems associated with hypereutectic Al-Si alloys in Lost Foam Casting (LFC). This investigation is a pioneering work undertaken to gain a better understanding of the role of primary silicon crystals and other phases in the LFC of hypereutectic Al-Si alloys. Time-temperature and first derivative curves were used to determine velocity of metal flow and to calculate solid fractions. Process parameters such as superheat, gating design and alloy composition were manipulated to change the morphology of primary silicon crystals. Microscopy and image analysis of castings enabled study of precipitated particles. Solidification, interlocking and melt sluggishness of precipitated particles significantly influenced fluidity, and the routine process parameters played a minor role.

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