Phase Evolution of Al85Co7Y8 Alloy during Mechanical Alloying

Bu çalışmada nanoyapılı Al85Co7Y8 (at.%) alaşımı, mekanik alaşımlama (MA) tekniği kullanılarak elementel tozların katı hal reaksiyonuyla sentezlenmiştir. Toz alaşımlar, argon gazı altında sertleştirilmiş paslanmaz çelik hazne ve bilyeler kullanılarak yüksek-enerjili bilyeli değirmen içerisinde 300 saatlik öğütme işlemine tabi tutulmuştur. Öğütme işlemi süresince numunelerdeki yapısal ve morfolojik değişimler X-ışını difraksiyonu (XRD) ve taramalı elektron mikroskobu (SEM) ile termal kararlılıkları ise diferansiyel termal analiz (DTA) ile incelenmiştir. MA işlemi sonucunda aşırı doymuş fcc-Al katı çözelti fazı içeren alaşımlar üretilmiştir. Al85Co7Y8 alaşımının 300 saatlik öğütme işlemi sonrasındaki kristalit boyutu yaklaşık 16 nm olarak bulunmuşturIn this study, the nanostructured AlCoY (at.%) alloy was synthesized by a solid state reaction from the constituent elemental powder mixture via mechanical alloying (MA). The powder mixture was ball milled for times up to 300 h in a planetary high energy mill using hardened steel vial and balls under argon atmosphere. Structural and morphological changes during the milling process were characterized by a combination of X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Thermal stability of the milled powders was investigated using differential thermal analysis (DTA). The results showed that supersaturated ?-Al solid solution was formed in the whole content of the milled material. The mechanically alloyed AlCoY powder for 300 h of milling indicated the formation of fine nanoparticles with a size of about 16 n

Microfabricated barcodes for particle identification

Microfabricated barcodes formed in SU8 photopolymer are presented as a method for identifying individual particles based on their diffraction patterns. Two designs of barcoded particles are considered; a single layer SU8 process and a two layer SU8 process. Theoretical data shows that for ideal barcoded particles it should be possible to obtain several million uniquely identifiable codes for particles as small as 50 microns in length

Fabrication of diffraction-encoded micro-particles using nano-imprint lithography

A nano-imprint lithography technique is described for fabrication of optically encoded microparticles (diffractive barcodes). The particles are fabricated from SU8 - a material which can be processed lithographically, and which can be used for attachment of molecular tags. The barcodes are identified by their unique diffraction pattern