Influence of Nanodispersions on Properties and Microstructure Features of Cast and T6 Heat-Treated Al Si Hypoeutectic Alloys

2012 ◽  
Vol 192-193 ◽  
pp. 76-82
Author(s):  
Iman El Mahallawi ◽  
Hoda Abdelkader ◽  
Laila Shehata ◽  
Asmaa Amer ◽  
Joachim Mayer ◽  
...  
Keyword(s):  
Lamellar Spacing ◽  
Light Metal ◽  
Nano Particles ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Mechanical Stirring ◽  
Heat Treated ◽  
Cast Alloys ◽  
Semi Solid ◽  
Function Relationship

Cast light metal alloys have retained their importance and unique characteristics as first candidates when cost-function relationship is considered. Hypoeutectic aluminum silicon alloys as (A356) exhibit several specific and interesting properties that qualify them to be used in many automotive and aeronautical applications. Evidence of significant enhancement in strength in the properties of Al-Si cast alloys by incorporating nano-particles have been recently presented. The present study aims at developing nano-dispersed Al-Si alloys with suitable casting methods that assure the dispersion of the nano-particles. In this work a number of cast samples of A356 were prepared by rheo-casting in a specially designed and built furnace unit allowing for the addition of the nano-particles into the molten Al-Si alloy in the semi-solid state with mechanical stirring. The microstructural features and the mechanical properties of the cast and T6 heat treated samples were investigated. The results obtained in this work showed enhancement in the mechanical strength of the nano-dispersed alloys, accompanied by significant increase in the elongation percentage, supported by evidence of refined dendrite arms length, and inter-lamellar spacing.

Correlation between Alloying Elements and Aging Parameters and Hardness and Machinability of Aluminum-Silicon Alloys Using Minitab Software

2015 ◽  
Vol 1101 ◽  
pp. 217-224
Author(s):  
Mahmoud M. Tash ◽  
Khaled A. Abuhasel ◽  
Saleh A. Alkahtani
Keyword(s):  
Artificial Aging ◽  
Drilling Force ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Alloying Additions ◽  
Surface Fraction ◽  
Solution Treated ◽  
Heat Treated ◽  
Si Content ◽  
Mg Content

The present study was undertaken to investigate the effect of alloying additions and aging parameters (time and temperature) on the hardness and machinability of Al-Si alloys. Hardness, drilling force and moment and number of holes drilled/tool measurements were carried out on specimens prepared from grain refined, Sr modified and heat treated Al-Si alloys. Aging treatments were carried out for the as solution treated (SHT) specimens (after quenching in warm water). The specimens were aged at different conditions; artificial aging was carried out at 180˚C, 200 ˚C and 220˚C for 2 and 5 h. Hardness, drilling force and moment and number of holes drilled/tool as a function of different metallurgical parameters (i.e. %Si content, %Mg content, heat treatment parameters (time and temperature), Cu-intermetallics surface fraction and Fe-intermetallic surface fractions) are analyzed to acquire an understanding of the effects of these variables and their interactions on the hardness and machinability of heat treated Al-Si alloys.

Semi-Solid Processing of Nano-SiCP/ Al-Si Composites and Mechanical Properties with Rheo-Casting

2019 ◽  
Vol 285 ◽  
pp. 33-38
Author(s):  
Shu Sen Wu ◽  
Du Yuan ◽  
Qiang Chen ◽  
Shu Lin Lü ◽  
Zhi Wei Huang
Keyword(s):  
A356 Alloy ◽  
Average Diameter ◽  
Sem Analysis ◽  
Nano Particles ◽  
Mechanical Stirring ◽  
Sic Particles ◽  
New Process ◽  
The Matrix ◽  
A356 Aluminum ◽  
Semi Solid

Generally nano-SiC particles are difficult to be added into molten aluminum metals because of poor wettability. Nano-SiC particles reinforced A356 aluminum alloy composites were prepared by a new process, i.e., a molten-metal process combined with mechanical stirring at semi-solid state and ultrasonic vibration method. The nano particles were β-SiCp with an average diameter of 40 nm, and pre-oxidized at about 850°C to form an oxide layer with thickness of approximately 3.6 nm. The SEM analysis results show that nano-SiC particles are dispersed well in the matrix and no serious agglomeration is observed. The tensile strength and elongation of the 2wt.% nano-SiCp/A356 composite in as-cast state are 259 MPa and 5.3%, and they are improved by 20% and 15% respectively compared with those of the A356 alloy.

Microstructure of Thixoformable Hypoeutectic Cast Iron

2012 ◽  
Vol 192-193 ◽  
pp. 219-224 ◽  
Author(s):  
Eugênio José Zoqui ◽  
Angel Sanchez Roca ◽  
Hipólito Domingo Carvajal Fals
Keyword(s):  
Cast Iron ◽  
Morphological Evolution ◽  
Raw Material ◽  
Heating Process ◽  
Compression Tests ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Final Microstructure ◽  
Semi Solid ◽  
Aluminum Silicon

The use of a specially designed hypoeutectic cast iron as a potential raw material for the thixoforming process is described in this paper. Thixoforming technology normally uses aluminum-silicon alloys such A356 and A357 as raw materials. Iron-based alloys are less common, despite the lower cost of the raw material. The paper describes the semi-solid behavior and corresponding final microstructure of a hypoeutectic gray cast iron after thixoforming tests. The Fe-2.6wt%C-1.5wt%Si alloy was prepared via conventional casting in sand molds. Samples were heated to the semi-solid state at 1160 and 1180oC and held at these temperatures for 0, 30, 90 and 120s, and then subjected to compression tests. Two-platen compression tests were carried out in an instrumented eccentric press in order to determine the semi-solid behavior. The holding time in the semi-solid range simulates the industrial heating process that is time-controlled rather than temperature-controlled. The semi-solid behavior indicated that the semi-solid cast iron behaves like aluminum-silicon alloys, presenting a stress of up to 24MPa under 80% strain and a corresponding apparent viscosity of up to 1.5*105 Pa.s at 1180oC. The final microstructure after compression testing was essential in determining the material’s morphological evolution. Tests revealed that heating up to the semi-solid range followed by thixoforming changes the material’s graphite morphology from type A to B (or E), but does not significantly affect the interdendritic arm spacing between graphite lamellae. The resulting structure is composed of fine graphite and pearlite.

scholarly journals Evaluation of Cracking Causes of AlSi5Cu3 Alloy Castings

2014 ◽  
Vol 59 (3) ◽  
pp. 1089-1092 ◽  
Author(s):  
Š. Eperješi ◽  
M. Matvija ◽  
ľ. Eperješi ◽  
M. Vojtko
Keyword(s):  
Automotive Industry ◽  
Pressure Casting ◽  
Operating Life ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Heat Treated ◽  
Low Pressure Casting ◽  
Alloy Castings ◽  
Pressure Die Casting

Abstract Recently, the castings made from aluminum-silicon alloys by pressure die casting are increasingly used in the automotive industry. In practice, on these castings are high demands, mainly demands on quality of their structure, operating life and safety ensuring of their utilization. The AlSi5Cu3 alloy castings are widely used for production of car components. After the prescribed tests, the cracks and low mechanical properties have been identified for several castings of this alloy, which were produced by low pressure casting into a metal mould and subsequent they were heat treated. Therefore, analyses of the castings were realized to determine the causes of these defects. Evaluation of structure of the AlSi5Cu3 alloy and causes of failure were the subjects of investigation presented in this article.

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.

Effects of T5 and T6 Heat Treatments Applied to Rheocast A356 Parts for Automotive Applications

2008 ◽  
Vol 141-143 ◽  
pp. 237-242 ◽  
Author(s):  
Mario Rosso ◽  
Ildiko Peter ◽  
R. Villa
Keyword(s):  
Fatigue Behaviour ◽  
Cyclic Stress ◽  
Industrial Applications ◽  
Fatigue Tests ◽  
Controlled Cooling ◽  
Test Analysis ◽  
Heat Treated ◽  
Mechanical Performances ◽  
Semi Solid ◽  
Number Of Cycles

The correlation between the evaluation of the mechanical and of the fatigue behaviour of the rheocast, T5 and T6 heat treated SSM A356 aluminium alloy with respect to the microstructures of the component has been investigated. The study has been carried out on a suspension arm injected in a rheocasting 800 tons plant in Stampal S.p.A. The new rheocasting is a process that allows obtaining the alloys in a semisolid state directly from the liquid state, by controlled cooling of the molten alloys. The resulting microstructures are very fine, free from defects and homogeneous: these characteristics improve the mechanical properties of the alloys and specially the response to cyclic stress, an important issue for a suspension component. After a preliminary tensile test analysis, axial high frequency fatigue tests have been carried out at room temperature on specimen cut out from the suspension arm to determine the Wöhler curve and the number of cycles to failure. The results of this work allow a comparison of the effects of heat treatment process, T5 or T6, on Semi-Solid components for industrial applications in the automotive field. On the basis of these analysis the correlation between microstructure and mechanical performances can be established.

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