Reducing contact resistance of high current connectors on electric vehicle by controlling contact pressure and addition of plating material
This paper studies on contact resistance on copper busbar connection relative to plating materials, plating thickness, and contact pressure. This study is important because busbar connection plays an important role on electric distribution performance. A good busbar connection would have low contact resistance, therefore low energy losses and better reliability. In this study, the sample are busbar connection without plating, busbar connection with zinc plating, busbar connection with nickel plating, and busbar connection with silver plating. First aspect that is going to be tested is contact resistance measurement without load on each. The next test is contact resistance measurement with DC load of 9, 18, and 27 A. Each test is conducted with the contact pressure variation of 5.6, 7.0, dan 8.4 MPa, and with plating thickness of 5, 15, and 25 μm. The result shows that busbar connection with 5 μm silver plating have much lower contact resistance compared to all the other configuration.
Injection lap riveting
Abstract This paper presents an injection lap riveting process to connect two sheets placed one on top of the other. The process is carried out at ambient temperature and differs from self-pierce riveting because its joining principle is based on plasticity and friction without fracture and formation of new surfaces. The working principle is based on two consecutive operations - first, a dovetail ring hole is machined in the lower sheet and then a semi tubular rivet is injected through the upper sheet into the dovetail ring hole of the lower sheet, by compression with a punch. The presentation is based on a combined experimental and numerical investigation and special emphasis is put on the influence of the dovetail ring hole geometry in material flow, riveting force, and pull-out and shear destructive forces. The last past of the paper includes details of a prototype cutting tool that was developed by the authors for producing the dovetail ring holes in-site and fostering the portability and applicability of the process.
Tailored synthesis of TiC∕a-C nanocomposite tribological coatings
Composite coatings made of nanocrystalline TiC (nc-TiC) particles and amorphous carbon (a-C) have been prepared in a double magnetron sputtering system using graphite and titanium targets under Ar bombardment. Chemical composition and microstructure of coatings were studied by transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), and x-ray diffraction (XRD) for a set of samples prepared varying the ratio and intensity of power applied to each magnetron. Changes in coatings microstructure, from a quasipolycrystalline TiC to a nanocomposite formed by nanocrystals of TiC embedded in an amorphous matrix of carbon (nc-TiC∕a-C), are observed depending on the synthesis conditions. Tribological and mechanical properties of coatings were tested using a pin-on-disk tribometer and an ultramicrohardness indenter, respectively. Coatings with moderate hardness (7–27GPa), low friction (0.1–0.2), and low wear rates (k∼10−7mm3∕Nm) were obtained. A percentage between 15% and 30% of TiC is found ...