Articles you may be interested inEffect of deposition temperature on electron-beam evaporated polycrystalline silicon thin-film and crystallized by diode laser Appl. Phys. Lett.
Recent finite element calculations [1] indicate that structures constructed from partially compacted hollow spheres exhibit a greater stiffness and strength than many other cellular structures at comparable density. It has been observed that gas atomization of metallic powders often leads to entrapment of the flow field gas [2]. The resulting hollow powders are an unwanted by-product in the sense that they lead to porosity and future sites of defect in solid parts. Here a method is developed to separate the hollow powders according to their size, shape and density. They are then consolidated to a porous structure. Examples of this are given for both a titanium alloy and a nickel-base superalloy. The compressive mechanical properties are measured and compared to those of other porous structures.
Currently, most high-technology materials are inspected for quality after processing, with very low yields, great variability and high costs. Intelligent process control potentially enables much greater yields of highquality materials, which will reduce the designers' inhibitions about consideration of new, emerging materials in the design of new products, and enable their earlier introduction into systems and their components. Development of concurrent engineering tools and systems, with the development of intelligent processing of materials technology as a cornerstone to concurrent engineering, will then lead to long-term changes in the way that organizations conduct product development. Potential benefits include a large reduction in the time required to develop new products, increased quality and reduced life-cycle costs.
The characteristics of A112Mo formed in aluminum annealed after implantation with selected maximum molybdenum concentrations were examined by analytical electron microscopy techniques. The A112MO was isolated as the only precipitate in the microstructure for maximum as-implanted molybdenum concentrations up to 11 atomic percent. The morphology of the A112MO can be selected by choosing the maximum as-implanted molybdenum level over the same concentration range. A predominantly lamellar A112MO precipitate structure formed when aluminum was annealed at 550°C after implantation with maximum molybdenum concentrations in the range of 3.3 - 4.4 at.%. The orientation of the body centered cubic (bcc) A112Mo precipitate with respect to the face centered cubic (fcc) matrix can be expressed as (123)p || (002)m and [301]p || [310]m. An explanation for the experimentally observed orientation relationship was developed based on the characteristic relationships between the bcc A112MO precipitate and the fcc matrix. A continuous film of A112MO formed in the surface modified region when aluminum was annealed after implantation with maximum molybdenum concentrations in the approximate range of 8-11 at.%. The microstructure of the A112Mo film was found to depend on the annealing temperature. A granular film formed after annealing at 550°C whereas a mottled film formed after annealing at 400°C. Sequential annealing experiments revealed that the mottled film transforms to a granular film which indicates the mottled film is metastable.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.