Alaa Abdel-Azim Elmoursi

Novel Electrical Joints Using Deformation Machining Technology Part I: Computer Modeling

This paper explores the use of deformation machining technology (DMT), originally developed at Bauman Moscow State Technical University, to make electrical joints and compare their performance to bolted and welded electrical joints. The DMT process is used to generate tooth-like profiles on two opposing surfaces that make the electrical joint, which are later joined by applying a mechanical load. To optimize the interfacing surface tooth-like profiles, a computational finite element model is developed. The model is used to simulate the mechanical joining of both Cu and Al DMT joints. The model is able to predict the most important parameters that contribute to enhancing the teeth interlocking and increasing the contact surface area. The model is successfully used in optimizing Cu-DMT joints; however, for Al-DMT joints the model predicted an unreliable electrical joint attributed to a spring-back effect that occurs after the mechanical load for making the joint is removed.

Novel Electrical Joints Using Deformation Machining Technology—Part II: Experimental Verification

This is the second part of the paper related to the exploration of deformation machining technology (DMT), originally developed at Bauman Moscow State Technical University, as it may apply to making electrical joints and comparing their performance to bolted and welded electrical joints. The DMT process is used to generate tooth-like profiles on two opposing surfaces that make the electrical joints which are later joined by applying a mechanical load. Part I contained a more detailed explanation of the DMT process and the description of the results of computer modeling of DMT joints in copper and aluminum. This paper provides the experimental results of the mechanical and electrical performance of copper and aluminum DMT joints which were compared to bolted and welded electrical joints of identical geometries. Measurements of tensile strength and electrical resistance, after thermal cycling and short-circuit testing, show equivalent or better performance of copper DMT joints compared with copper bolted and welded joints. In addition, it is observed that copper DMT joints have superior performance when compared with aluminum DMT joints, this was attributed to lesser gap filling and the springback effect that occurs after the mechanical load for making the joint is removed. The computer modeling results reported in Part I of this paper support these observations.

Tribological Characteristics of AlMgB14 and Nanocomposite AlMgB14-TiB2 Superhard Coatings

This study investigated the friction and wear characteristics of two super-hard coatings on M2 steel. One was AlMgB14 , produced by pulsed laser deposition (PLD), and the other was a nanocomposite of AlMgB14 -TiB2 , produced by physical vapor deposition (PVD). Tests were conducted under unidirectional and reciprocating sliding against AISI 52100 bearing steel in both dry and oil-lubricated conditions. The AlMgB14 coating exhibited an encouraging but short-lived low friction stage (μ = 0.2) in dry sliding. The AlMgB14 -TiB2 coating reduced the wear rates by one order of magnitude relative to the M2 steel and three orders of magnitude for the counterface in dry sliding. This nanocomposite coating also demonstrated significant extension (>2.5X) of the low friction (non-scuffing) stage when sliding under starved lubrication.© 2008 ASME