This study conducts an experimental investigation to explore the impact of the traverse speed of a tool on the tensile strength and micro-structural peculiarities of joints attained during friction stir welding of Cu alloy namely CDA 101 at plates. In this process, other parameters including spinning speed of tool (1100 rpm) and downward force (6 kN) were kept constant. A tool with a cylindrical tapered pin geometry was made to traverse at varying speeds, from 20 mm/min to 45 mm/min. It was observed that the CDA 101 joints fabricated at 20 mm/min were entirely free of flaws, while the joints fabricated at other traverse speeds of the tool were featured several weld flaws. Grains in the center of the stir zone of the joints obtained at 20 mm/min were uniformly distributed and homogeneous due to the significant volume of frictional heat and sufficient stirring force. The highest tensile strength of 200. 65 MPa (nearly 85. 38% of base metal) was exhibited by the joint attained at 20 mm/min.

The hot cracking susceptibility can be determined by establishing the transition temperature between brittle and ductile fracture at high temperature tensile testing of in situ solidified samples. High temperature tensile properties were determined for commercial cathodic pure Cu and Cu- 30%Zn alloy. The transition temperatures for pure Cu and Cu-30%Zn were evaluated from ultimate tensile stress, true strain and area reduction at different testing temperatures. The results show that hot cracking in pure Cu also occurred below and near to its melting temperature. It can be proposed that in this case excess vacancies and vacancy diffusion and condensation are the dominating mechanisms for hot crack formation. The transition temperature for Cu- 30%Zn was much lower than its solidus temperature and this alloy has more susceptibility to hot cracking as compared to pure Cu. The effect of two different cooling rates (15 °C/min and 60 °C/min) on the transition temperature was investigated. The results show that by increasing cooling rate, the transition temperature will increase. The morphology of fracture surfaces for both ductile and brittle modes were evaluated by SEM Two different morphologies, i.e. interdendiritic and intergranual fracture, was found. 

This study focused on the effect of electroslag remelting process (ESR) on microstructure and composition of as-cast Cu-Cr-Zr alloy. The results revealed that applying ESR process resulted in a more uniform distribution of alloying elements. However, slight aggregation of large precipitates and inclusions existed in as-cast ingot. It was observed that impurities like P, S and Mg which had significant effect on electrical property were eliminated after ESR process. Moreover, further optimization of alloy composition which in turn would affect its mechanical and electrical properties was obtained through using ESR technique, successfully.

This study aims at investigating changes in microstructure and strength of W alloy and Cu bimetals with varying spark plasma sintering (SPS) temperature and percentage of copper in W-Cu-Ni alloy. After SPS of W (12 wt%)-Cu (14 wt%)-Ni (3 wt%) alloy powder into consolidated discs at 1350 °,C, they were spark plasma sintered to copper discs at various temperatures. Assessment of the interface microstructure and shear strength was performed by field emission scanning electron microscpe (FESEM) and shear strength test, respectively. Results indicated SPS is successful in forming a perfect metallic bond with monolithic interface and high shear strength of about 45 MPa in Cu/W-12Cu-3Ni bimetal that is extra high quality and not reported in previous investigations.

An Ag–Cu (AC) bimetallic alloy nanoparticles in various proportions were fabricated by facile electrochemical process is presented in this work. Apart from the electrochemical method of synthesis, the surface morphology, crystal structure and texture as well as the optical properties of the nano alloy have been investigated. The surface morphology and the particle size of the Ag–Cu deposits were deliberated by scanning electron microscopic studies. The preferred orientation and average particle size of the AC NTs were obtained by X-ray diffraction analysis.The well-dispersed AC nano alloy (NA) exhibited ultrafine size and high crystallinity corresponding to face centered cubic Ag and Cu. Ultraviolet–visible spectroscopy was performed to study the optical properties of the nano alloy and the results showed that the nano alloys have wide band gap energies 3.18, 3.57 and 3.03 eV for AgCu, AgCu2 and AgCu3 NAs, respectively. The studies on size, morphology and composition of the nanoparticles were performed by means of transmission electron microscopy, and energy dispersive X-ray Analysis.