It is reported that three respectively from the College of Polymer Science and Engineering, Jeonnam University, Kwangju University, the three South Korean university researchers to develop a thermally stable silver-based conductive 3D printing wire. Their research, just published in Advanced Materials magazine, could have a significant impact on 3D printing of integrated electronic components. In the electronics manufacturing industry, conductive 3D printing makes it easy to customize parts by minimizing the amount of conductive fillers. In this study, South Korean researchers developed a 3D printed wire with less than 3% by weight of preconductive filler by forming a silver-organic composite (SOC). The use of a chelating agent allows the SOC to have thermal stability (TS), and thermal degradation is minimized to 0.91% (weight ratio), even at high temperatures as well as 3D printing by the cage effect. In addition, the researchers also directly designed a compact extruder with a short (3cm) heating phase. It is used to make wires based on TS-SOC to minimize thermal degradation. In addition, silver nanoparticles (SNPs) with a diameter of 70 to 90 nm are uniformly formed and densified conductive percolation networks are formed by releasing the chelating reaction and chemical reduction of the surface. Finally, not only electrical characteristics up to 55.71 S cm-1 were obtained, but internal short-circuits due to plugging problems with conventional conductive wires can also be overcome. This TS-SOC-based, thermally stable conductive wire enables continuous 3D printing. This method is cost-effective by using the least amount of filler, and makes it possible to produce custom 3D electrodes using organic silver nanoparticles.
Asbestos was added as an common ingredient to Brake Pads post-WWI, as car speeds began to increase, because research showed that its properties allowed it to absorb the heat (which can reach 500 °F) while still providing the friction necessary to stop a vehicle. However, as the serious health-related hazards of asbestos eventually started to become apparent, other materials had to be found. Asbestos brake pads have largely been replaced by non-asbestos organic (NAO) materials in first world countries. Today, brake pad materials are classified into one of four principal categories, as follows:
Non-metallic materials - these are made from a combination of various synthetic substances bonded into a composite, principally in the form of cellulose, aramid, PAN, and sintered glass. They are gentle on rotors, but produce a fair amount of dust, thus having a short service life.
Semi-metallic materials - synthetics mixed with varying proportions of flaked metals. These are harder than non-metallic pads, more fade-resistant and longer lasting, but at the cost of increased wear to the rotor/drum which then must be replaced sooner. They also require more actuating force than non-metallic pads in order to generate braking torque.
Fully metallic materials - these pads are used only in racing vehicles, and are composed of sintered steel without any synthetic additives. They are very long-lasting, but require more force to slow a vehicle while wearing off the rotors faster. They also tend to be very loud.
Ceramic materials - Composed of clay and porcelain bonded to copper flakes and filaments, these are a good compromise between the durability of the metal pads, grip and fade resistance of the synthetic variety. Their principal drawback, however, is that unlike the previous three types, despite the presence of the copper (which has a high thermal conductivity), ceramic pads generally do not dissipate heat well, which can eventually cause the pads or other components of the braking system to warp.However, because the ceramic materials causes the braking sound to be elevated beyond that of human hearing, they are exceptionally quiet.
Auto Brake Pads,Car Pad Shims,Brake Pad Shims,Autozone Brake Pads LIXIN INDUSTRIAL & TRADE CO.,Limited , https://www.jmautoplugs.com