Ti_1-xAl_xN coated tools are commonly used in high-speed machining, where the cutting edge of an end-mill or insert is exposed to temperatures up to 1100 °C. Here, we investigate the effect of Yttrium addition on the thermal stability of Ti_1-xAl_xN coatings. Reactive DC magnetron sputtering of powder metallurgically prepared Ti_0.50Al_0.50, Ti_0.49Al_0.49Y_0.02, and Ti_0.46Al_0.46Y_0.08 targets result in the formation of single-phase cubic (c) Ti_0.45Al_0.55N, binary cubic/wurtzite c/w-Ti_0.41Al_0.57Y_0.02N and singe-phase w-Ti_0.38Al_0.54Y_0.08N coatings. Using pulsed DC reactive magnetron sputtering for the Ti_0.49Al_0.49Y_0.02 target allows preparing single-phase c-Ti_0.46Al_0.52Y_0.02N coatings. By employing thermal analyses in combination with X-ray diffraction and transmission electron microscopy investigations of as deposited and annealed (in He atmosphere) samples, we revealed that Y effectively retards the decomposition of the Ti_1-x-yAl_xY_yN solid-solution to higher temperatures and promotes the precipitation of c-TiN, c-YN, and w-AlN. Due to their different microstructure and morphology already in the as deposited state, the hardness of the coatings decreases from ~35 to 22 GPa with increasing Y-content and increasing wurtzite phase fraction. Highest peak hardness of ~38 GPa is obtained for the Y-free c-Ti_0.45Al_0.55N coating after annealing at T_a = 950 °C, due to spinodal decomposition. After annealing above 1000 °C the highest hardness is obtained for the 2 mol % YN containing c-Ti_0.46Al_0.52Y_0.02N coating with ~29 and 28 GPa for T_a = 1150 and 1200 °C, respectively. Full article

Random phase encoding is a unique technique for volume hologram which can be applied to various applications such as holographic multiplexing storage, image encryption, and optical sensing. In this review article, we first review and discuss diffraction selectivity of random phase encoding in volume holograms, which is the most important parameter related to multiplexing capacity of volume holographic storage. We then review an image encryption system based on random phase encoding. The alignment of phase key for decryption of the encoded image stored in holographic memory is analyzed and discussed. In the latter part of the review, an all-optical sensing system implemented by random phase encoding and holographic interconnection is presented. Full article

Honeycomb monoliths consist of a large number of parallel channels that provide high contact efficiencies between the monolith and gas flow streams. These structures are used as adsorbents or supports for catalysts when large gas volumes are treated, because they offer very low pressure drop, short diffusion lengths and no obstruction by particulate matter. Carbon-based honeycomb monoliths can be integral or carbon-coated ceramic monoliths, and they take advantage of the versatility of the surface area, pore texture and surface chemistry of carbon materials. Here, we review the preparation methods of these monoliths, their characteristics and environmental applications. Full article

In this paper we will demonstrate how a thermodynamic-kinetic method can be utilized to rationalize a wide range of interfacial phenomena between Sn-based lead-free solders and Ni metallizations. First, the effect of P on the interfacial reactions, and thus on the reliability, between Sn-based solders and electroless Ni/immersion Au (ENIG) metallizations, will be discussed. Next, the effect of small amounts of Cu in Sn-based solders on the intermetallic compound (IMC), which forms first on top of Ni metallization, will be covered. With the help of thermodynamic arguments a so called critical Cu concentration for the formation of (Cu,Ni)₆Sn₅ can be determined as a function of temperature. Then the important phenomenon of redeposition of (Au,Ni)Sn₄ layer on top of Ni₃Sn₄ IMC will be discussed in detail. The reasons leading to this behaviour will be rationalized with the help of thermodynamic information and an explanation of why this phenomenon does not occur when an appropriate amount of Cu is present in the soldering system will be given. Finally, interfacial reaction issues related to low temperature Sn-Zn and Sn-Bi based solders and Ni metallization will be discussed. Full article