Wyniki wyszukiwania - BazTech

1

Fabrication and effect of Mg–Zn solid solution via Zn foil interlayer alloying in FSW process of magnesium alloy

Sahu Prakash Kumar, Pal Sukhomay, Das Bipul, Shi Qingyu

Archives of Civil and Mechanical Engineering

|

2020

|

Vol. 20, no. 4

589--603

EN

The present study demonstrates the friction stir welding (FSW) process can be used as a mechanical alloying tool to fabricate a solid solution. An attempt has been taken for alloying the AM20 Mg base matrix using Zn at the weld zone during friction stir welding. Successful joints with sound mechanical properties and enhanced quality attributes are observed in the welds. Use of Zn alloying element at the nugget zone, the joint efficiency reached 90% to that of the base material and also which is about 25% more than the strength obtained in the case of without alloying element set of experiments. The addition of Zn alloy to Mg substrate forms Mg–Zn binary solid solution reinforcing intermetallic compounds, namely MgZn and Mg7Zn3 resulting in improved joint properties. This research work also reports the investigative outcomes, namely flow in the joint area, metallurgical deviation, microstructural modification, and diffusion of the constituent alloying element during the welding process. The targeted objective was effectively accomplished and the Zn alloyed stir area can fulfil the required application. The findings from the selective alloying process may be relevant for the implementation of industrial users over Mg alloys using a FSW process with better weldability and improved strength.

2

Transient finite element simulation and microstructure evolution of AA2219 weld joint using gas tungsten arc welding process

Arunkumar S., Shrikrishna A. K., Paulraj S., Devakumaran K., Kumar S. R.

Advances in Science and Technology. Research Journal

|

2016

|

Vol. 10, nr 31

64--73

EN

In this study we focus on finite element simulation of gas tungsten arc welding (GTAW) of AA2219 aluminum alloy and the behavioral of the microstructure before and after weld. The simulations were performed using commercial COMSOL Multiphysics software. The thermal history of the weld region was studied by initially developed mathematical model. A sweep type meshing was used and transient analysis was performed for one welding cycle. The highest temperature noted was 3568 °C during welding. The welding operation was performed on 200×100×25 mm plates. Through metallurgical characterization, it was observed that a fair copper rich cellular (CRC) network existed in the weld region. A small amount of intermetallic compounds like Al2Cu is observed through the XRD pattern.

3

Effect of tool geometry and welding speed on mechanical properties and microstructure of friction stir welded joints of aluminium alloys AA6082-T6

Patil H. S., Soman S. N.

Archive of Mechanical Engineering

|

2014

|

Vol. LXI, nr 3

455--468

EN

Friction stir welding is a solid state innovative joining technique, widely being used for joining aluminium alloys in aerospace, marine automotive and many other applications of commercial importance. The welding parameters and tool pin profile play a major role in deciding the weld quality. In this paper, an attempt has been made to understand the influences of welding speed and pin profile of the tool on friction stir welded joints of AA6082-T6 alloy. Three different tool pin profiles (tapered cylindrical four flutes, triangular and hexagonal) have been used to fabricate the joints at different welding speeds in the range of 30 to 74 mm/min. Microhardness (HV) and tensile tests performed at room temperature were used to evaluate the mechanical properties of the joints. In order to analyse the microstructural evolution of the material, the weld’s cross-sections were observed optically and SEM observations were made of the fracture surfaces. From this investigation it is found that the hexagonal tool pin profile produces mechanically sound and metallurgically defect free welds compared to other tool pin profiles.

PL

Spawanie tarciowe z przemieszaniem (FSW) jest innowacyjną techniką spawalniczą stosowaną szeroko przy łączeniu stopów aluminiowych w lotnictwie, przemyśle okrętowym, motoryzacyjnym i w wielu innych istotnych komercyjnie zastosowaniach. Parametry spawania i profil trzpienia narzędzia grają główną rolę gdy chodzi o jakość spawu. W pracy podjęto próbę zbadania wpływów szybkości spawania i profilu trzpienia na spawanie tarciowe z przemieszaniem stopu AA6082-T6. Trzy różne profile trzpienia (zwężający się cylindryczny z czterema żłobkami, trójkątny i sześciokątny) były używane do wykonania spawów przy różnych szybkościach spawania w zakresie od 30 do 74 mm/min. W celu oceny właściwości mechanicznych spawów wykonano badanie mikrotwardości (HV) oraz testy na rozciąganie w temperaturze pokojowej. Dla oceny mikrostrukturalnej ewolucji materiału przeprowadzono obserwacje przekrojów spawu metodą optyczną, a obserwacje powierzchni pęknięć przy pomocy elektronowego mikroskopu skaningowego (SEM). Na podstawie badań stwierdzono, że zastosowanie sześciokątnego profilu trzpienia narzędzia daje spawy solidne mechanicznie i wolne od defektów, lepsze niż dla pozostałych profili trzpienia.