Abstract: A high electron mobility transistor (HEMT) device is disclosed. The HEMT device includes a substrate with epitaxial layers over the substrate that includes a buffer layer having a dopant comprising aluminum, wherein the concentration of aluminum within the buffer layer is between 0.5% and 3%. The epitaxial layer further includes a channel layer over the buffer layer and a barrier layer over the channel layer. A gate contact is disposed on a surface of the epitaxial layers. A source contact and a drain contact are also disposed on the surface of the epitaxial layers, wherein the source contact and the drain contact are spaced apart from the gate contact and each other.

Abstract: A tubular axle having a spindle and a bearing shoulder is formed directly into heat-treated tubing. The method generally includes a heating operation, and a two stage forming operation. The first operation is to induction heat a steel tubular axle blank to a temperature less than 1500 degrees Fahrenheit. The next operation includes forcing a preform die assembly onto the tubular blank to reduce a length of the blank to a second diameter while forming an intermediate section having a first and second ramped section. The final operation includes forcing an upset die assembly onto the end of the blank to form a gathered material section formed intermediate the first ramped section and the second ramped section. The second diameter provides a pre-machined diameter for the final axle spindle and the gathered material section provides a pre-machined area for the final integral bearing shoulder.