Resistance spot welding (RSW) is widely used in industries such as the aerospace, automotive, and electrical application industries. RSW is very useful for joining aluminum and its welding parameters lead to good quality joints. This research studied the influence of the welding parameters, such as welding current, welding time, and the electrode force, of micro resistance spot welding (MRSW) on the mechanical properties and fracture of a nugget of aluminum alloy (AA) 1100. AA 1100 plate with a thickness of 0.4 mm was used in this experiment. An alternating current (AC) RSW machine and electrode were used in this study. The welding parameters used in this study are welding current, welding time, and electrode force. Holding time is assumed to be constant. The welding time values of 6 CT, 8 CT, and 10 CT were combined with a welding current of 8 kV, and electrode forces of 32 kg, 42 kg, and 52 kg. The results showed that by increasing the electrode force, the load rate decreases, and the elongation distance tends to decrease, except for the electrode force of 52 Kg. The effect of the electrode force on the diameter and thickness of the weld nugget was not significant.
All metals have unique advantages and disadvantages in terms of their mechanical properties. Advantages such as flexibility are needed for construction and for the manufacture of sophisticated products. Some industries have improved the mechanical properties of metals by welding dissimilar ones together, such as aluminum alloy (AA) to stainless steel (SS) to reduce vehicle weights in order to improve fuel consumption. However, little research has been conducted on using micro resistance spot welding (mRSW) to join SS and Al by inserting a zinc (Zn) sheet between them as an interlayer. In this study, the mechanical properties of the weldment are tested using a shear test and Vickers micro hardness test. The results are compared using welding times of 6, 8 and 10 cycle times (CTs) and welding currents of 5 and 8 kA during the mRSW process. It is found that the SS, Zn and AA sheets could be joined with mRSW using an 8 kAA welding current and a 6 CT welding time. The micro hardness in the AA-Zn dissimilar joint increased relative to SS-Zn. Using a Zn sheet also improved displacement in the tensile shear test; however, it also increased the hardness of the diffusion zone.
The smart city is an exciting concept for improving the quality of the city. However, a smart city needs participation from citizens and all related stakeholders to use the technologies effectively in order to achieve the goal and solve the problems. Even though the city already has high-tech infrastructures, participation still required to provide ideas, inputs, and roles within the development of smart city concepts. This research aims to describe and analyze the current state of the e-Participation frameworks and propose a novel framework for smart cities. The analysis will go through a systematic literature review. Hopefully, this study makes contributions by providing a novel framework of e-Participation for smart cities. This research has implications for theory and practice. For theory, the novel framework can be added to the body of knowledge of e-participation, e-government, and smart cities fields. For practice, the framework will be useful for practitioners, policymakers, people and other stakeholders related to the smart city governance to increase citizen participation through technology-based services.
In the dissimilar materials and dissimilar thin thickness sheets joining, welding current and welding time parameters of resistance spot welding (RSW) effect weld ability. RSW used for joining thin plate less than 1000 μm is called micro-resistance spot welding (μRSW). The objective of this article is to study the effect of welding current and welding time to the joining dissimilar thin thickness materials and the microstructure of a weld joint. The thickness of Al 1100 is 400 μm, and KS 5 Spring Steel is 200 μm. Welding parameters are Cycle Time 0.5, 1, 1.5, Welding Current 1kA and 2 kA, and holding time 10 second. Welding current 1kA, Cycle time of 0.5 produce maximum shear load of 227.4 N and fracture area of 6.644 mm2. Welding current 2 kA, cycle time of 1.5 affect maximum load of 222.7 N and fracture area of 10.559 mm2. Welding parameters lead to the majority fracture on aluminum material. The welding current and cycle time do not significantly affect maximum shear load and fracture area.
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