In embodiments of an expandable mobile device, the device includes first and second housing parts that slide-engage relative to each other to extend and retract the device. According to the invention, the metal of the aforementioned metal part is melted by the electric arc alone without the use of any laser beam. The formulation contains essential amounts of calcium, magnesium Vitamin D, Vitamin K-1, Folic Acid and Soy Isoflavones, as well as other ingredients and healthy filler components. A second part may be provided with a plastic housing, circuit boards containing electrical components, and a bezel. 001 to 10; c is MgNi mole ratio in the range from 0.