New developments in solid dielectric life extension technology

Research on ultrasonic welding of copper wire harness and aluminum alloy: based on experimental method and GA-ANN model

The scope and limitations of first generation expert systems

Symmetric split Hopkinson compression and tension tests using synchronized electromagnetic stress pulse generators

Self-piercing riveting of similar and dissimilar metal sheets of aluminum alloy and copper alloy

Due to its simplicity in instrumentation and data analysis, uniaxial tensile tests are commonly used for determining the plastic stress-strain relation of a sheet metal. However, the tensile stress-strain data obtained using the standard procedure is valid only up to the moderate strain level just before the onset of diffuse necking in the specimen gage section. Once the diffuse necking starts, the plastic deformation of the specimen becomes increasingly non-homogenous within the necked region. Questions arise regarding the validity of extrapolating the uniaxial stress-strain data to very large strains when one analyzes the forming failure of the sheet metal. Here an experimental technique and the related application procedure for obtaining rate-dependent, anisotropic, tensile stress-strain data of sheet metals at large strains up to fracture are described. Detailed plastic strain mapping results of a tapered commercially pure titanium thin sheet specimen are presented to characterize necking of the thin sheet. A brief discussion of a hybrid experimental and numerical methodology for estimating the strain hardening, strain rate sensitivity, and plastic anisotropy of sheet metals at large tensile strains is given. Preliminary results on necking in aluminum alloys, copper alloys, and low-carbon steel thin sheets are also presented.

Niobium (Nb) was initially applied in the industry in 1933 to stabilize stainless steels against intergranular corrosion. Around 1970, niobium started to be used in many technological applications, especially in heat treatments at high temperatures, in the form of superalloys and, over the past four decades, Nb has been employed on an industrial scale. During recent years, applications of niobium have increased steadily in various segments such as: micro-alloyed steels, super alloys, thin films, medical implants, titanium and aluminum alloys, superconductors and copper alloys, electrolytic and ceramic capacitors. The worldwide demand for Nb grew at an annual rate of 10% between the years 2000-2010, were the sectors of energy, automotive and construction of the largest consumers FeNb. In 2000 the brazilian production was 35,458 t of Nb and, in 2007, reached 82,000 t of concentrate Nb. Brazil has the world's largest reserves of Nb (98.53%), which totaled 842.4 million t. So, in this paper is made a study on the evolution of the production of niobium in Brazil and its main industrial and technological applications.

Measuring deformation mostly is based on the contact type of measurements which utilize the gauges and instruments. But this type of contact will lead to error in the precise measurement because of errors by the contact, measuring instruments, and human. So, feel proud to introduce image processing in the field of measurement. Here, in this study deals the measurement of deformation of deep drawing specimen by image processing which is called as contact free method. This is invasive method of measurement in two dimensions.Deep drawing process is an important sheet metal forming in which flat sheet metal had been forced through the die in association with the forward punch force and opposing blank holder force. As the blank passes through the tool set converts 2D bank into 3D cup formation. The process of achieving the required diameter of the cup can be produced in single stage or multistage operation. In this study, experimental study had been conducted on single stage deep drawing process for assessment of deformation and strain in aluminum alloy, copper alloy and brass alloy. Cylindrical cup deep drawing experimental tests were performed with blank of 60 x 60 square plate with 1 mm thickness. Eventually this new approach will help to optimize the geometry parameters deep drawing specimen correlation with the Matlab results.

In China, iron, chromium and manganese are classified as ferrous metals, with other 64 kinds of metals as nonferrous metals. China usually refers to copper, aluminum, lead, zinc, nickel, tin, antimony, mercury, magnesium and titanium in huge production and consumption as ten major nonferrous metals. Ferrous metals in general sense also include nonferrous alloys. The term “non-ferrous alloys” refers to alloys based essentially on nonferrous metals (usually more than 50 %) and mingled with one or several other kinds of elements. Aluminum alloys, copper alloys and magnesium alloys etc are frequently-used nonferrous alloys.

Tubular hollow fibre electrodes for CO2 reduction made from copper aluminum alloy with drastically increased intrinsic porosity

Tension-torsion measurements were made with applied strain on ACSR, AACSR,ACAR, aluminum and aluminum alloy conductors, as well as on groundwires. Results were compared with predictions of a model based on mechanical properties of constituent wires and the geometry of the multistrand cable. True tensile strength of each cable was predicted accurately. Deviations were found in the torque values of cables containing galvanized steel strands. Interstrand friction, not considered in the model, is thought to be responsible for the deviation. Frictionless interaction of strands was found to be a reasonable approximation for aluminum and aluminum alloy stands.

Crevice corrosion for dissimilar metal contacts is a key problem in engineering applications. This work has attempted to prevent the ingress of corrosive media into the crevice between aluminum alloy and copper by controlling the roughness (machining accuracy) of the contact surfaces. Both electrochemical and alternating dry/wet immersion tests were used to investigate the corrosion resistance of aluminum alloy–copper contacts with different contact surface roughness. Considering the relationship between the contact surface roughness and the liquid–solid contact angle and the crevice width, a finite element model based on fluid dynamics theory is established to analyze the effect of the contact surface roughness on the seawater infiltration depth in the contact crevice. The distribution of corrosion products on the aluminum alloy and copper surfaces is observed by optical microscope and scanning electron microscope. The phase composition of the corrosion products is analyzed by X‐ray diffraction technique. The results show that the corrosion resistance of the contact improves as the roughness of the contact surface decreases. This is attributed to the fact that the infiltration of seawater is retarded due to the decrease in the crevice width and increase in the contact angle with the decrease in the contact surface roughness.

Synthetic ester and blended insulating oils have attracted widespread attention owing to their great potential on performance enhancement because of the high capacity with tailorable molecular structure and mixable components. In this work, natural ester insulating oil (FR3) is blended into the synthetic tetra-ester insulating oil (KA) via mixing and oscillating. The physicochemical and electrical property measurements of the ester blends indicate the flash point, fire point, and AC breakdown voltage of KA are capable to be increased, and the dissipation factor of KA is reduceable by the addition of FR3. As expected, a series of physicochemical properties of the ester blends follow a quasi-linear relationship with the variation (in vol%) of FR3. However, the flash point (closed cup) is verified with high nonlinearity according to the results of thermogravimetric-derivative and thermogravimetric-differential scanning calorimetry (TG-DSC) tests in nitrogen. The optimized ester blend (85 vol% (KA):15 vol% (FR3)) is typically manifested by high flash point (260°C), low pour point (-51°C), low dissipation factor (1.44%), high AC breakdown voltage (76.5 kV), and high onset temperature of DSC either in nitrogen (229.99°C) or in the air (272.05°C). The activation energy is analyzed based on the Arrhenius equation, dissipation factor, and resistivity values in order to recognize the optimum ratio of the ester blends.

Hydrogen porosity in directionally solidified aluminium–copper alloys: a mathematical model

The patent design around is key to the company when launch a new product. So product development must not impinge the patent right. TRIZ is a power tool for patent analysis and innovation. The evolution patterns and routes help design to find out current technologies' developing status and imply the next developing level of the technologies. The problem is found out with consideration of how to achieving the next generation of technology. The contradiction solving principles is the tool to help designer get primal solution for the innovation. The design solution which design around existing patents and have higher perform would construct by contradiction matrix and inventive principles. The belt conveyor is a case study and developed to improving the performance without impinging existing patent.

From measurements of the radius of curvature of extended dislocation nodes observed by transmission electron microscopy, stacking-fault energies have been determined for a number of copper and silver base aluminium and zinc solid solution alloys and also for a number of nickel-cobalt alloys. Rough estimates of about 40, 25 and 150 erg cm−2 respectively can be made of the stacking-fault energies of copper, silver and nickel. The accuracy of the measurement and the possibility of segregation of solute atoms to stacking faults are discussed.