The aluminum matrix composites with ceramic dispersoids can be separated by density difference concept. In the proposed work composite scrap is recycled using an oil fired furnace. The scrap is melted in the furnace and temperature is maintained below 740 degree centigrade. Because of the density difference the lighter dispersoids will float and heavier dispersoids will settle down. The clean melt is separated be removing the floating and settled dispersoids, and then filtering using ceramic filters.

ZA-27 based metal matrix composites (MMCs) have been prepared with 1, 2, 3, and 4% of reinforcement by compocasting method. Sample specimens of dimensions 70mm � 10mm � 2mm were machined from the prepared ingots. The damping behavior and dynamic young's modulus of the base alloy and the particulate reinforced composites was studied over a temperature range of 30�C to 300�C by using a dynamic mechanical analyzer. The damping capacity of the materials was observed to increase with the increase in temperature whereas the dynamic modulus was found to decrease with the increase in temperature. The damping capacity at lower temperature may be attributed to coefficient of thermal expansion (CTE) mismatch induced dislocations and intrinsic damping of the matrix alloy whereas damping capacity at higher temperature may be attributed to matrix/reinforcement interface and thermoelastic damping.

Document image analysis and recognition (DIAR) is the process of performing the overall interpretation of document images. These document images conform, to an implicit or explicit document structure, which may be viewed as a guiding by a model for the class of documents of interest. This model describes the physical relationships between the entities that make up the document. Character recognition is applied at the final level of this process to provide an encoding of the symbols contained in a logical entity such as a paragraph or table once the characters have been isolated by other stages. The variable error rate and lack of determination demands considerable error correction as well as interactive validation.

The oxidation behavior of aluminium composite with 0, 2, 4, and 6% by weight of albite at 200 to 500�C has been investigated. With in the experimental temperature ranges a parabolic weight gain was observed. The weight gain as a function of oxidation time becomes linear after an initial period on oxidation formation; an oxide scale was found whose morphology depends on temperature, cooling rate and subscale formation at the interface between the matrix and reinforcement. The presence of albite particulate reinforcement has very little effect on the oxidation behavior. The interface oxidization rate was found to be higher than that of other regions. The oxidation products were either metallic oxides or ceramic oxides. The exposure time of specimens to oxidation was 1000 minutes at various temperatures. In the present work key principles of alloy oxidation were discussed. Also the paper emphasizes various reactions taking place and the activation energies involved in the oxidation reactions.

An accelerated aging response was detected in Al6061 based metal matrix composites, in age hardening, electrical resistivity, EDS diffraction, TEM, DSC and microstructural observations. The samples were subjected to aging at 32, 80, 180, and 320�C for 0.01 to 100 hours. The peak of the hardness and the resistivity values of the MMCs increased with increasing reinforcement content and ageing temperature although the MMCs precipitation kinetics (peak) in the matrix alloy is significantly accelerated due to the presence of reinforcement. It is thought that the dislocation assisted nucleation processes reduce the apparent activation energy for precipitation, and a higher nucleation density of precipitates in the composites. Changes in the properties of the composites during aging have been explained on the basis of microstructural alterations during ageing.

Document image analysis and recognition (DIAR) is the process of performing the overall interpretation of document images. These document images conform to an implicit or explicit document structure, which may be viewed as a guiding by a model for the class of documents of interest. This model describes the physical relationships between the entities that make up the document. Character recognition is applied at the final level of this process to provide an encoding of the symbols contained in a logical entity such as a paragraph or table once the characters have been isolated by other stages. The variable error rate and lack of determination demands considerable error correction as well as interactive validation.

Flyash, a residue of burning coal / lignite at thermal power stations, has generally been considered as a waste material, there is renewed interest in developing alternatives to disposal. One possible solution for this problem is to incorporate Flyash particles into cement-based materials. Utilization of Flyash should minimize environmental impact and maximize conservation of natural resources. In this study, use of Flyash wastes in producing cement stabilized soil blocks has been investigated. There are several parameters namely, the rate of added Flyash waste, the amount of cement used as stabilizer and block processing. The processing is exactly the same as per the soil stabilized blocks, except that fly-ash of specified quality, constitute an additional input material. The flyash is partially substituted for cement at 16% to 24% of total Cement content used, depending on the target Compressive Strength of the final product, thereby saving on costs. The Experimental investigation involves least investment and makes use of ordinary equipment with normal water spray curing. The blocks are good for making nonload-bearing walls or pre-cast blocks for nonstructural filler wall masonry. The use of Flyash as addition to cement paste show satisfactory results in mechanical properties, it has few desirable characteristics such as lower density and higher fracture toughness. The paper concludes that it is possible to significantly, improve the dimensional stability and performance of cement stabilized soil blocks to the extent, that they can be suitably used for construction of Pedestrian and low volume roads.

The unlubricated sliding wear behaviour of Zinc-Aluminum (AZ-27) alloy composites reinforced with zircon particles of size 30-50 ?m is evaluated in the present study. The content of zircon in the alloy was varied from 1-5% in steps of 2 weight %. A pin-on-disc wear testing machine was used to evaluate the wear rate, in which a hardened EN24 steel disc was used as the counterface. The results indicated that the wear rate of the composites was lesser than that of the matrix alloy and it further decreased with the increase in zircon content. However, the wear rate increased with the increase in load and the sliding distance, both in the case of composites and the alloy. Increase in the applied load increased the wear severity by changing the wear mechanism from abrasion to particle cracking induced delamination wear. It was found that the wear resistance increased monotonically with an increase in zircon content.

Most aluminium alloys have good corrosion resistance in natural atmospheres. Heat treatable alloys can however be susceptible to grain boundary attack in certain tempers as a result of local electro-chemical cells caused by precipitates and precipitate free zones. Al-Li binary alloys have been reported to be susceptible to intergranular corrosion resulting from the anodic nature of the Al-Li precipitates. The addition of magnesium, alters the transformation sequence and Al-Li-Mg alloys have been reported to have good resistance to intergranular corrosion. The experimental work described in this paper utilized accelerated corrosion tests established to predict long-term outdoor behaviour of existing alloy systems. The test results for lithium-containing alloys ought to be correlated in a similar manner, but there is a lack of documented data on the corrosion of these alloys in natural environments. The results reported here should be treated with caution when comparing with known alloy systems.

This paper describes a study of the mechanical properties of cast lead-antimony alloy composites containing silicon carbide (SiC) particles of size 90-150 ?m and of contents ranging from 0% to 5% by weight. The 'vortex method' of production was employed in which the SiC particles were poured into the vortex created by stirring the molten metal at 400�C by means of a mechanical agitator. The results of this study revealed that as SiC composition was increased, there were significant increases in the ultimate tensile strength (UTS), hardness, torsional strength and impact strength of the composite, accompanied by a reduction in its ductility. An attempt is made in the paper to provide explanations for these phenomena. � 1996.