Development of techniques for joining and welding materials on a micrometer scale is of great importance in a number of applications, including life science, sensing, optoelectronics and MEMS packaging. In this paper, methods of welding and sealing optically transparent materials using a femtosecond fiber laser (1 MHz & 1 μm) were demonstrated which overcome the limit of small area welding of o...

in this paper, dissimilar resistance spot welding of aisi 1075 eutectoid steel to aisi 201 stainless steel is investigated experimentally. for this purpose, the experiments are designed using response surface methodology and based on four-factor, five-level central composite design. the effects of process parameters such as welding current, welding time, cooling time and electrode force are inv...

Abstract Regarding porosity formation and gas content, choosing the appropriate shielding for laser welding is essential achieving high-quality joints. Keyhole-induced tendency nitrogen content in SS 304 stainless steel welds were investigated based on gases during fiber welding. Beads-on-plate autogenous made at 5 kW continuous wave (CW) N 2 Ar mixtures. Optical metallography, micro-focused X-...

The present research work is aimed at highlighting the safety aspects in a welding process. The process of welding is being used extensively for the last several decades as one of the most commonly used joining techniques for various metallic structures including ships, airplanes, automobiles, bridges, pressure vessels, etc. In this research article, some issues related to the procedures adopte...

In this paper, a low cost, high performance and full PC-based sensor system for the pulsed gas metal arc welding (PGMAW) is described. It allows the visual online observation of all states of the welding process, including the material transition, and all welding situations without an additional lighting unit. Additionally, the synchronized measurement of the welding current and welding voltage...

Submerged Arc welding process is automated and semiautomated high deposition down hand welding process not vertical or over welding process, The fundamental difference of this welding process is that the Arc is not visible it is submerged into the flux. Weldment is fully submerged the heat loss is minimum and the thermal efficiency is very high up to 80-90%. A constant power sources and control...

There are many industries where austenitic stainless steel needs to be welded specially in power generation industries. Unfortunately the austenitic stainless welding has several fabrication and metallurgical drawbacks when welded by using conventional fusion welding methods, which can often leads to in-service failure. The most pronounced fabrication faults are hot cracks due to inadvertent us...

Friction stir lap welding of 7B04 aluminum alloy was conducted in the present paper, and the effect of welding speed on the defect features and mechanical performance of lap joints was investigated. The results indicate that the hook defect at the advancing side (AS) can reduce the effective thickness of the top sheet, and the sheet thinning level is gradually lowered by increasing the welding ...

Friction stir welding is a solid state joining process. High strength aluminum alloys are widely used in aircraft and marine industries. Generally, the mechanical properties of fusion welded aluminum joints are poor. As friction stir welding occurs in solid state, no solidification structures are created thereby eliminating the brittle and eutectic phases common in fusion welding of high streng...