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Abstract

The microstructure of as-cast and as-HIPed (hot isostatic pressed) K403 superalloy was investigated using a scanning electron microscopy (SEM), as component analysis was conducted by energy dispersive x-ray spectrometer (EDS). It was found that the microstructure of the alloy was improved significantly through HIP. Firstly, the microporosity and micropores in as-cast alloy were ameliorated effectively and the morphology of grains tended to be uniform. Moreover, the morphology of carbides at grain boundaries transformed from thread-like to granular. Uppermost, the size, shape and volume fraction of γ′ phase were significantly optimized and γ′ precipitates in two different sizes were generated in matrix. Nanoindentation experiment was then carried out to obtain the nanohardness and elastic modulus of as-cast and as-HIPed K403 superalloy. The results revealed an obvious increase in both nanohardness and elastic modulus after HIP. Conclusions could be drawn from the research that HIP could improve the microstructure of as-cast K403 superalloy, which could enhance the mechanical properties of the alloy positively.

Abstract

We calculate the electronic properties of austenite and martensite Fe-9%Mn alloys using the self consistent full-potential linearized-plane-wave method under the generalized gradient approximation full lattice relaxation. By minimizing total-energy, the lattice constants in their ground states were determined. We discuss the total energy dependence of the volume, and density of states (DOS).

Abstract

Titanium dioxide(TiO2) is a well-known material which is non-toxic with efficient photoactivity, high stability, low-cost and corrosion-resistant. Up to today’s technology, TiO2 films are coated for various applications in the scientific area. In this study, bilayer TiO2 films were coated on indium tin oxide(ITO) layers that have different characteristic properties. The devices designed as homemade of Direct Current Magnetron Sputtering (DCMS) and Spray Pyrolysis Deposition (SPD) coating methods were used to coat the first and second layers of bilayer TiO2 films, respectively. The optical and crystalline characterizations of bilayer TiO2 films were analyzed by UV-VIS spectroscopy and XRD techniques. The XPS spectrum showed that O2 molecules simply oxidize from Ti3+ to Ti4+ after SPD coating method. The characterization results of TiO2 films showed change in optical band gap value and crystalline structure of TiO2 bilayer.

.694 MeV γ-ray following thermal neutron capture and reported by the nuclear probe in three different positions. These Frenkel pairs are stable up to at least 373 K. Key words: α-Hf; Frenkel Pairs; Nuclear Quadrupole Interaction. PACS numbers: 61.66.Dk; 61.80.-x; 76.80.+y 1. Introduction Radiation damage in metals has been studied in the past by various methods, e. g. high energy electrons, heavy ions, or neutrons [1]. For the latter, applications in fusion reactors and nuclear power reactors were one of the driving forces. In this respect it is somewhat sur- prising

phenomena. PACS®(2010). 81.20.EV, 72.15.-V, 82.40.ck, 82.0.-s, 89.20.kk, 61.66.DK, 66.30.Ny. 1 Introduction In the past quarter century the increasing cost of energy and increased environmental awareness has lead to a global re- quirement for the reduction of automotive emissions. One strategy for the reduction of emissions is reducing the gross weight of vehicles. As the weight is decreased, less fuel is consumed to propel the vehicle. The average vehicle in 1977 had a mass of 1666 kg, and in 2001 the average weight had been reduced to 1504 kg; an over 136 kg reduc- tion