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The coarse prior-β grain structure in titanium alloys produced by additive manufacturing is associated to mechanical anisotropy and limited fatigue life. Here we report a novel methodology to refine such structure by rapid heat treatment of Ti–6Al–4V produced by laser powder-bed fusion. The refinement was analysed using high-temperature EBSD that showed, for the first time, how high angle boundary β grains nucleated and grew with quasi-equiaxed morphology by epitaxial recrystallization. These findings show the potential for such heating regime to be applied to control grain size, morphology and distribution in a wider category of structural alloys produced by additive manufacturing. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Abstract The lack of knowledge about the interdependence between energy and metals hinders sustainable management of the two essential resources. In this study, a hybrid framework which combines the Environmentally Extended Input-Output Analysis (EEIOA) and Ecological Network Analysis (ENA) was constructed to evaluate energy-metals use and flows within China's economic system in 2012, from the perspective of nexus. Furthermore, the structural properties of nexus networks and mutual relationships between sectors were simultaneously explored. The results show that hybrid energy (direct energy + metals-related energy) and hybrid metals (direct metals + energy-related metals) used by all the sectors were 1.22 and 1.05 times their direct energy and direct metals use, respectively. In both hybrid energy and metal networks, mining industry and construction industry had a strong control and dependence relationship (over 50%) with other sectors, reflecting the tight inter-sectoral connection between energy use and metals use. Therefore, stabilizing these main control and dependence pathways is essential to the system's effective operation. In addition, alleviating excess industrial capacity and optimizing economic structure are two effective measures to improve the currently low energy-metals circulation efficiency within China's economy system. By revealing the nexus between energy and metals in China, this study provides important policy implications for trade-offs and synergies between energy and metals use. Graphical abstract Image 1 Highlights • The interdependence between energy and metals was quantified from a nexus perspective. • System stability and inter-sectoral energy and metals linkages in the nexus network were investigated. • The circulation of energy and metals within China's economic system were both in a state of low efficiency. • Feasible strategies were provided for sustainable energy and metals management. [ABSTRACT FROM AUTHOR]

Rapid urbanization drives the expansion of urban power girds, which involves enormous energy intensive products such as steel and concrete and inevitably results in a great quantity of carbon emissions. However, little has been done to investigate urban power girds' impact on carbon emissions. To solve this problem, this study makes efforts to calculate the carbon emissions of urban power grid in Jing-Jin-Ji region, one of the most populous and economically dynamic regions in China, in light of the hybrid method. Moreover, the depreciation life of urban power grids is taken into consideration for the first time, which avoids the underestimation of the accumulated carbon emissions of urban power grid due to depreciation. The results show that the accumulated carbon emissions of urban power grid in Jing-Jin-Ji region are 2.71E+06 t CO 2 eq. in 1993. When it comes to 2014, this figure increases by over 7.2 times. The majority of the carbon emissions by typical urban substations and transmission line projects are contributed by electrical equipment, steel and construction industries. 4 scenarios are set to predict the future carbon emissions by power grids in Jing-Jin-Ji region. The highest accumulated carbon emissions in 2020 are projected to be 7.63E+07 t CO 2 eq. under the condition shortest depreciation life (SDL) in the First Year Finished (FYF) scenario. Regression analysis is also carried out to show some influential factors such GDP's influence on power grids' carbon emissions, suggesting that the correlation between carbon emissions and regional economic development becomes more significant after Power System Reform Plan in 2002. This study not only draws a holistic picture of power grid but also bears significance to policies and actions in urban regions. [ABSTRACT FROM AUTHOR]