This work investigates the effect of bismuth (Bi) addition, 1 wt% Bi, on wettability of the Sn-3.0Ag-0.5Cu (SAC305) ternary Pb-free solder alloy. Adding Bi to SAC305 decreased the contact angles (θ) of the Sn-2.0Ag-0.5Cu-1.0Bi (SAC-1Bi) quaternary Pb-free solder alloy, which were measured by using of the sessile drop method at various temperatures (250, 280 and 310 °C) on Cu substrate in argon (Ar) atmosphere. Microstructures, inter-metallic phases and melting temperatures were analyzed by optical microscope, scanning electron microscopy, X-ray diffraction, and differential scanning calorimetry, and effects of the amount of Bi on microstructure were investigated. The experimental results exhibited that when the addition of Bi was 1 wt%, changing in melting temperature of SAC-1Bi solder was insignificant, but the wetting angles (θ) of the solder alloy decreased which were measured by using of the sessile drop method at various temperatures. The lowest θ was obtained as 35.6° for SAC-1Bi alloy at 310 °C.

Magnesium and its alloys have become important structural materials in the last couple of decades due to their exceptional and mechanical properties. In this study, the effects of the introduction Cd, Bi, and Sn alloying elements were introduced into AM60 alloys produced from Mg-Al-Mn triple junction in order to improve the microstructural and mechanical properties. The weight percent of the alloying elements was chosen as 0.5% wt. besides the introduction of the additional alloying elements, the effect of cooling rate on microstructural and mechanical properties of the alloys have been investigated. The results showed that the alloying elements introduced to AM60 resulted in an improvement in the mechanical properties of the alloys, which is attributed to the changes in the microstructure. The higher cooling rate led to the formation of the finer α-Mg master matrix which in turn enhanced the mechanical properties of the alloys. It was observed that the intermetallic phase of β-Mg17Al12 at the grain boundaries became thinner due to the rapid cooling rate and the introduction of the alloying elements, and the continuity decreased and the intergranular distance shortened. The addition of the alloying element increased the tensile strength of the AM60 alloy from 140 MPa to 210 MPa and the elongation values increased from 5% to 22%. The effects of the alloying elements and the cooling rate on the hardness and yields properties of the samples were also studied.

This study deals with the microstructure, mechanical, and wear properties of the extruded ZK60 matrix composites strengthened with 45 µm, 15% silicon carbide particle (SiC) and 760 nm, 0.2–0.5% aluminium nitride (AlN) nanoparticle reinforcements. First, the reinforcement elements of the composites, SiC and AlN mixtures were prepared in master-magnesium powder, and compacts were formed under 450 MPa pressure and then sintered. Second, the compacted reinforcing elements were placed into the ZK60 alloy matrix at the semi-solid melt temperature, and the melt was mixed by mechanical mixing. After the melts were mixed for 30 min and a homogeneous mixture was formed, the mixtures were poured into metal moulds and composite samples were obtained. After being homogenized for 24 h at 400 °C, the alloys were extruded with a 16:1 deformation ratio at 310 °C and a ram speed of 0.3 mm/s to create final composite samples. After microstructure characterization and hardness analysis, the dry friction behavior of all composite samples was investigated. Depending on the percentage ratios of SIC and AlN reinforcement elements in the matrix, it was seen that the compressive strength and hardness of the composites increased, and the friction coefficient decreased. While the wear rate of the unreinforced ZK60 alloy was 3.89 × 10⁻⁵ g/m, this value decreased by 26.2 percent to 2.87 × 10⁻⁵ g/m in the 0.5% AlN + 15% SiC reinforced ZK 60 alloy.