The use of thermodynamic simulation for the selection of hypoeutectic aluminum–silicon alloys for semi-solid metal processing

2004 ◽  
Vol 364 (1-2) ◽  
pp. 48-54 ◽  
Author(s):  
Q. Han ◽  
S. Viswanathan
Keyword(s):  
Thermodynamic Simulation ◽  
Solid Metal ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Metal Processing ◽  
Semi Solid ◽  
Selection Of ◽  
Aluminum Silicon

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.

SSM Provides Important Advantages; So, why has SSM Failed to Achieve Greater Market Share?

2014 ◽  
Vol 217-218 ◽  
pp. 481-486 ◽  
Author(s):  
John L. Jorstad
Keyword(s):  
Turbulent Flow ◽  
Heat Treating ◽  
Solid Metal ◽  
Light Metals ◽  
Solidification Shrinkage ◽  
Air Entrapment ◽  
Thin Sections ◽  
Metal Processing ◽  
Semi Solid ◽  
Minimum Heat

Semi solid metal processing has numerous technical and economic advantages, such as viscous, non-turbulent flow (thus no air entrapment during casting), ability to fill ultra-thin sections (thus reduced part weight), little solidification shrinkage in the die (thus little or no porosity), minimum heat imparted to tooling (thus long tool life) and good response to T-5 aging (thus reduced heat treating costs). Still, SSM has never achieved a prominent position in the field of light metals casting Why? Perhaps the reason was largely the down economy of recent years and SSM will yet emerge with the prominence once expected of it.

Impact of melt treatment on semi-solid metal processing

2007 ◽  
Vol 436 (1-2) ◽  
pp. 86-90 ◽  
Author(s):  
Sahrooz Nafisi ◽  
Reza Ghomashchi
Keyword(s):  
Solid Metal ◽  
Melt Treatment ◽  
Metal Processing ◽  
Semi Solid

scholarly journals Surface Characterization and Tribological Performance of Anodizing Micro-Textured Aluminum-Silicon Alloys

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1862 ◽  
Author(s):  
Luanxia Chen ◽  
Zhanqiang Liu ◽  
Bing Wang ◽  
Qinghua Song ◽  
Yi Wan ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Sliding Friction ◽  
Tribological Performance ◽  
Area Ratio ◽  
Micro Milling ◽  
Dry Sliding ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Aluminum Silicon

Eutectic aluminum-silicon alloys present high frictional coefficient and a high wear rate due to the low hardness under sliding friction conditions. In this paper, the eutectic aluminum-silicon alloy was textured firstly by micro-milling operations. Then, the micro-textured specimen was subjected to anodizing to fabricate alumina films. The surface topography, surface roughness, and bearing area ratio of micro-textured and anodizing micro-textured specimens were measured and characterized. For the anodizing micro-textured specimens, the surface roughness and superficial hardness increase compared with those for micro-textured ones. Tribological tests indicate that anodizing micro-textured samples present lower friction coefficient of 0.37 than that of flat samples of 0.43 under dry sliding conditions. However, they exhibit higher friction coefficient at 0.16 than that of flat samples of 0.13 under oil-lubricated conditions. The difference between the friction coefficient of anodizing micro-textured and flat samples under dry and oil-lubricated conditions is ascribed to the influence mechanism of surface roughness, bearing area ratio curves, and its relative parameters on the tribological performance of testing samples. The dry sliding friction coefficient has a positive correlation with bearing area ratio curves, while they present negative correlation with bearing area ratio curves under oil-lubricated conditions. The synergy method treated with micro-milling and anodizing provides an effective approach to enhance the dry sliding friction property of eutectic aluminum-silicon alloys.

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