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Optimization of Process Parameters of Ultrasonic Welding on Dissimilar Metal Joints

Mohan Kumar Anand, Rajasekar R., Karthik Vaduganathan, Kheawhom Soorathep

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 3

887--892

EN

Nowadays the automotive industry mostly prefers innovative solid-state welding technologies that would enable to welding of lightweight and high-performance materials. In this work, 3105-H18 Aluminium alloy (Al) and pure Copper (Cu) specimens with 0.5 mm thickness have been ultrasonically welded in a dissimilar (Al-Cu) manner. Optimization of process parameters of ultra-sonic welding has been carried out through full factorial method, three levels of variables considered for this experimental studies namely, weld pressure, amplitude, and time, also each variable interaction with welding strength has been studied. Additionally, micro-hardness and microstructure investigation in welded joints has been studied. The result shows that the weld strength greatly influenced weld amplitude at a medium and higher level of weld pressure. The interface micro-hardness of the welded joint has lower compared to the base metal.

2

The Influence of Mg Additive on the Structure and Electrical Conductivity of Pure Copper Castings

Kranc M., Sikora G., Górny M., Garbacz-Klempka A.

Archives of Foundry Engineering

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2017

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Vol. 17, iss. 4

85--90

EN

The aim of this paper was to attain defect free, pure copper castings with the highest possible electrical conductivity. In this connection, the effect of magnesium additives on the structure, the degree of undercooling (ΔTα = Tα-Tmin, where Tα – the equilibrium solidification temperature, Tmin – the minimum temperature at the beginning of solidification), electrical conductivity, and the oxygen concentration of pure copper castings have been studied. The two magnesium doses have been investigated; namely 0.1 wt.% and 0.2 wt.%. A thermal analysis was performed (using a type-S thermocouple) to determine the cooling curves. The degree of undercooling and recalescence were determined from the cooling and solidification curves, whereas the macrostructure characteristics were conducted based on a metallographic examination. It has been shown that the reaction of Mg causes solidification to transform from exogenous to endogenous. Finally, the results of electrical conductivity have been shown as well as the oxygen concentration for the used Mg additives.

3

Experimental investigations of the pure copper produced by equal channel angular pressing

Greger M., Muskalski Z., Wiewiórowska S.

Hutnik, Wiadomości Hutnicze

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2015

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Vol. 82, nr 1

27--30

EN

Equal channel angular pressing (ECAP) is one of the methods of severe plastic deformation (SPD) that produces ultra-fine grained materials. Experiments were conducted in order to analyses the influence of equal-channel angular pressing on the microstructure and hardness of copper. The samples were processed by ECAP trough total of 14 passes at 20°C using the processing route BC. The ECAP processing refines the grain size. The hardness increases with the number of passes, i.e. it increases with a decrease in the grain size.

PL

Metoda przeciskania przez kanał kątowy (ECAP) jest jedną z metod przeróbki plastycznej, pozwalającą na otrzymanie materiału charakteryzującego się ultradrobnoziarnistą strukturą. Badania eksperymentalne przeprowadzono w celu oceny wpływu zastosowania procesu przeciskania przez kanał kątowy na mikrostrukturę i twardość miedzi. Proces prowadzono w 14 przepustach w temperaturze 20°C. Zastosowanie procesu ECAP wpływa na rozdrobnienie ziarna. Twardość miedzi wzrasta wraz z liczbą przepustów, tzn. wzrasta wraz ze spadkiem rozmiaru ziaren.