Optimization of the Microstructural Evolution of Al-8%Si in Cooling Slope Device

The aim of this work was to develop understanding of microstructural evolution of the alloy casted in semi-solid condition using a cooling slope and conventional casting followed by ECAP in a 120odie. Feed materials were prepared by cooling slope casting and conventional casting for ECAP process. The microstructures and Vickers hardness of the worked materials extruded by two routes (A and BC) were evaluated. The primary α-Al phase tends to be elongated after processing by route A. However, its morphology was similar in nature to the microstructure of the as-cast sample after processing by route BC. The Si particles become fragmented during ECAP processing and are more nearly globular in shape and uniform in size than in the as-cast sample. The microstructure of the semi-solid cast ECAPed samples was more homogenous than that of the conventional cast ECAPed sample followed by ECAP for both routes. The hardness of semi-solid cast ECAP samples was also higher than that of conventional cast ECAPed samples for both routes.

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Microstructural Evolution of AZ91 Alloy Containing 3%Ca Prepared by Cooling Slope

Solid State Phenomena - Semi-Solid Processing of Alloys and Composites X ◽

10.4028/3-908451-59-0.427 ◽

2008 ◽

pp. 427-432

Author(s):

Ali Khosravani ◽

Hossein Aashuri ◽

P. Davami ◽

A. Narimannezhad ◽

A. Foroughi ◽

...

Keyword(s):

Microstructural Evolution ◽

Az91 Alloy ◽

Cooling Slope

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Microstructural Evolution of ETIAL 160 Aluminium Alloy Feedstock Produced by Cooling Slope Casting

Solid State Phenomena - Semi-Solid Processing of Alloys and Composites X ◽

10.4028/3-908451-59-0.575 ◽

2008 ◽

pp. 575-580

Author(s):

Nurşen Saklakoğlu ◽

Yücel Birol ◽

Şefika Kasman

Keyword(s):

Aluminium Alloy ◽

Microstructural Evolution ◽

Cooling Slope ◽

Cooling Slope Casting

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Microstructural Evolution of A356 Al Alloy During Flow Along a Cooling Slope

Transactions of the Indian Institute of Metals ◽

10.1007/s12666-012-0208-8 ◽

2012 ◽

Vol 65 (6) ◽

pp. 669-672 ◽

Cited By ~ 22

Author(s):

Prosenjit Das ◽

Sudip. K. Samanta ◽

B. R. K. Venkatpathi ◽

Himadri Chattopadhyay ◽

Pradip Dutta

Keyword(s):

Microstructural Evolution ◽

Al Alloy ◽

Cooling Slope

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Microstructural Evolution in Reduced TiO2

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100097089 ◽

1981 ◽

Vol 39 ◽

pp. 74-75

Author(s):

W. T. Donlon ◽

S. Shinozaki ◽

E. M. Logothetis ◽

W. Kaizer

Keyword(s):

Microstructural Evolution ◽

Point Defects ◽

Extended Defects ◽

Small Deviations ◽

Controlled Atmospheres ◽

Limited Solubility ◽

Thin Foils ◽

Heat Treated ◽

Porous Polycrystalline ◽

Crystallographic Shear

Since point defects have a limited solubility in the rutile (TiO2) lattice, small deviations from stoichiometry are known to produce crystallographic shear (CS) planes which accomodate local variations in composition. The material used in this study was porous polycrystalline TiO2 (60% dense), in the form of 3mm. diameter disks, 1mm thick. Samples were mechanically polished, ion-milled by conventional techniques, and initially examined with the use of a Siemens EM102. The electron transparent thin foils were then heat-treated under controlled atmospheres of CO/CO2 and H2 and reexamined in the same manner.The “as-received” material contained mostly TiO2 grains (∼5μm diameter) which had no extended defects. Several grains however, aid exhibit a structure similar to micro-twinned grains observed in reduced rutile. Lattice fringe images (Fig. 1) of these grains reveal that the adjoining layers are not simply twin related variants of a single TinO2n-1 compound. Rather these layers (100 - 250 Å wide) are alternately comprised of stoichiometric TiO2 (rutile) and reduced TiO2 in the form of Ti8O15, with the Ti8O15 layers on either side of the TiO2 being twin related.

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