This study was undertaken to investigate the effects of Cu and solution heat treatment on the microstructure and hardness of cast Al-Al4Sr metal matrix composite. Different amounts of Cu (0.3, 0.5, 1, 3 and 5 wt.%) were added to the composite. Specimens were heat treated at 500 °C for 4 hours followed by water quenching. Microstructural studies were assessed by the use of optical microscope, sc...

The pathogenic mutant (P174L) of human Sco1 produces respiratory chain deficiency associated with cytochrome c oxidase (CcO) assembly defects. The solution structure of the mutant in its Cu(I) form shows that Leu-174 prevents the formation of a well packed hydrophobic region around the metal-binding site and causes a reduction of the affinity of copper(I) for the protein. K(D) values for Cu(I)W...

There is a growing concern that dietborne metal toxicity might be important in aquatic ecosystems. However, the science behind this matter is insufficiently developed to explicitly and accurately account for this in metal regulation or risk assessment. We investigated the effects of a chronic exposure of Daphnia magna to an elevated level of Cu (3000 microg Cu/g dry wt) in their diet (the green...

Several candidate alloys have been suggested as high-temperature lead-free solder for Si die attachment by different researchers. Among them, Zn–Al based alloys have proper melting range and excellent thermal/electrical properties. In this study, Zn–Al–Mg–Ga solder wire was used to attach Ti/Ni/Ag metallized Si die on Cu lead-frame in an automatic die attach machine. Die attachment was performe...

Sn–Ag–Cu composite solders reinforced with nano-sized, nonreacting, noncoarsening 1 wt% TiO2 particles were prepared by mechanically dispersing TiO2 nano-particles into Sn–Ag–Cu solder powder and the interfacial morphology of the solder and flexible BGA substrates were characterized metallographically. At their interfaces, different types of scallop-shaped intermetallic compound layers such as ...

Addition of TiO2 to a polytetrafluoroethylene (PTFE) particle-dispersed composite contributes to the self-cleaning properties of the water-repellent composite. However, its application is limited to outdoor usage or under ultraviolet (UV) irradiation. In this study, a novel visible-light-sensitive photocatalytic and superhydrophobic material was developed by adding Cu/WO3 to a PTFE particulate ...

W and Cu can be found in separate phases the W-Cu composites since these elements do not dissolve each other neither liquid nor solid phase, but with mechanical alloying it is possible to produce nonequilibrium alloys In this work nanostructured were produced by planetary ball milling. The powder was sintered on 900 °C 950 50 MPa pressure applied. meso- microstructure of samples, investigated S...

Porous structured silicon or porous silicon (PS) powder was prepared by chemical etching of silicon powder in an etchant solution of HF: HNO₃: H₂O (1:3:5 v/v). An immersion time of 4 min was sufficient for depositing Cu metal from an aqueous solution of CuSO₄ in the presence of HF. Scanning electron microscopy (SEM) analysis revealed that the Cu particles aggregated upon an increase in metal co...

60) to be used for fabricating jewellery, so alloying additions are made to increase the hardness. Platinum jewellery alloys usually have platinum contents of 90 wt.% and higher. The most common alloys are hallmarked as 950 platinum (95 wt.%). Unlike carat gold (Au) jewellery alloys, where relatively large additions can be made (to alter the properties of the alloy such as its hardness or colou...