Search Results (2)

The tandem metal inert gas (MIG) process uses two wires that are continuously fed through a special welding torch and disbursed to form a single molten pool. Within the contact tip of the modern approach, the wires are electrically insulated from one another. This study identified the effect of welding electrode spacing on the distortion of AA5052 aluminum plates and different mechanical properties including hardness and thermal cycle using grey relational analysis. Plate distortion was subsequently predicted using the grey prediction model GM (1, 6). This research used a pair of 400 mm × 75 mm × 5 mm of AA5052 plates and electrode distances of 18, 27, and 36 mm. The welding current, voltage, welding speed, and argon flow rate were 130 A, 23 V, 7 mm/s, and 17 L/min, respectively. The temperature was measured using a type-K thermocouple at 10, 20, 30, and 40 mm from the center of the weld bead. The smallest distortion at an electrode distance of 27 mm was 1.4 mm. At an electrode distance of 27 mm, the plate may reach a proper peak temperature where the amount of heat input and dissipation rate are similar to those for electrode distances of 18 mm and 36 mm. The highest relative VHN of 57 was found in the BM, while the lowest, 46, was found in the WM, showing good agreement with their respective grain sizes. Six parameters were designed using grey relational analysis (GRA) and subsequently employed in the grey prediction model GM (1, 6). Process evaluation results show that predictions for welding distortions are consistent with actual results, thus, the GM (1, 6) model can be used as a predictive model for welding distortions of 5052 aluminum plates. Full article

Due to the rapid economic development in China, the conflict between the increasing traditional energy consumption and the severe environmental threats is more and more serious. To ease the situation, greater use of wind energy in China could be the solution for energy conservation and sustainable environment in the long run. This paper describes the presentation of wind power in China, which covers distribution, bases, installed capacity, power generation from the spatial perspective and the environmental benefit. In addition, grey model (GM(1,1) ) and scenario analysis are employed to forecast the installed capacity in China from 2017 to 2025, then the evaluation of two methods is presented. By this research, the results are shown as the following: (1) the North region has great wind energy with 2500–3000 giga watt (GW) and the offshore wind energy in the Southeast is abundant; (2) the Inner Mongolia base located in North China makes a great contribution to wind power as well as having great potential for wind power development with the potential of 1300 GW; (3) the growth rate of installed capacity and wind power generation in China is declining with 100% in 2006 to 30% in 2015, 107% in 2009 to 17% in 2015, respectively; (4) the “three North” region has made a great contribution to current installed capacity and wind power generation with 74% and 71%, respectively; (5) wind power has significant environmental benefits with coal reduction of 23,887 × 10⁴ tce, CO₂ reduction of 66,854 × 10⁴ tons and SO₂ reduction of 173 × 10⁴ tons in total from 2008 to 2015; (6) the installed capacity in China from 2017 to 2025 is predicted utilizing a GM(1,1) model with 38,311.1810 × 10³ GW in 2025, while, with a scenario analysis, the installed capacity will reach up to 40,000 × 10³ GW in 2025 under the high GDP growth rate and 29,000 × 10³ GW in 2025 under the low GDP growth rate, respectively. Finally, it can be concluded that China has a solid foundation for the wind power development due to its abundant wind resources and great potential for wind power. Furthermore, the sustainable development can be guaranteed, and reduction in energy usage as well as emissions can be achieved by promoting wind power widely and effectively. Full article