Evolution of the surface structure the proton-irradiated tungsten during isochronal annealing in the temperature range 600-1000 °C

This paper presents the research results the surface structure evolution of high-purity tungsten after irradiation with 350 keV protons and subsequent annealing in the temperature range 600 – 1000 °C. Irradiation to a fluence of 5×1017 cm‒2 leads to blisters formation on the irradiated surface. Successive two-hour annealing results in the evolution of the distribution of blisters - the total number of blisters decreases while the fraction of larger blisters increases. At an annealing temperature of 1000C, the blisters dissolve. Do not observed the blisters disclosure and surface flaking both after proton irradiation and subsequent annealing in temperature range 600 – 1000 °C.

Annealing Induced Saturation in Electron Concentration for V-Doped CdO

As-grown Ar-deposited Cd1−xVxO and Ar/O2-deposited Cd1−yVyO feature lower and higher electron concentrations than 4 × 1020 cm−3, respectively. After isothermal and isochronal annealing under N2 ambient, we find that the two series exhibit a decrease or increase in electron concentrations until ~4 × 1020 cm−3 which is close to Fermi stabilization energy (EFS) level of CdO, with the assistance of native defects. An amphoteric defects model is used to explain the changing trends in electron concentrations. The tendencies in mobility further confirm our results. This work may provide some strategies to predict the electrical properties in CdO.

Influence of Heat Treatment on Microhardness and Phase Transformations in Cast and Homogenized 7075(-Sc-Zr) Aluminium Alloys

The positive effect of Sc,Zr-addition on mechanical properties in Al-based alloys preferred for automotive manufacture to produce lightweight vehicles is generally known. Microstructure, mechanical, electrical and thermal properties of the conventionally cast and homogenized (475 °C/60 min) Al-5.4wt.%Zn-3.1wt.%Mg-1.5wt.%Cu (7075) and Al-5.2wt.%Zn-3.0wt.%Mg-1.4wt.%Cu-0.2wt.%Sc-0.1wt.%Zr (7075-ScZr) alloys during isochronal annealing were characterized. Precipitation reactions were studied by microhardness, electrical resistivity and conductivity measurements, differential scanning calorimetry and positron annihilation spectroscopy. Microstructure observation by scanning and transmission electron microscopy proved the Zn,Mg,Cu-containing eutectic phase at grain boundaries in the alloys. The melting of this eutectic phase was observed at ~ 481 °C for the both alloys. The distinct changes in microhardness and electrical resistivity isochronal curves as well as in heat flow of the alloys studied are mainly caused by dissolution of the clusters/Guinier-Preston (GP) zones and by formation of the metastable phase particles of the Al–Zn–Mg–Cu system. Clusters/GP zones were formed during the cooling and/or in the course of the storage at room temperature. These clusters/GP zones were formed predominantly by Mg and Zn alloying elements. Hardening effect after isochronal annealing at temperatures above ~ 300 °C reflects the Sc,Zr-addition in both states of the 7075-ScZr alloy. Probably precipitation of the T-phase (Al2Zn3Mg3) and S-phase (Al2CuMg) particles took place during the annealing. The Sc,Zr-addition does not significantly influence precipitation of the particles formed in the Al–Zn–Mg–Cu system.