Determination of Microstructural Changes By Severely Plastically Deformed Copper-Aluminum Alloy: Optical Study

Our work deals with the problem of producing a complex metal-ceramic composite using the processes of internal oxidation (IO) and severe plastic deformation. For this purpose, Cu-Al alloy with 0.4wt.% of Al was used. IO of sample serves in the first step of the processing as a means for attaining a fine dispersion of nanosized oxide particles in the metal matrix. Production technology continues with repeated application of severe plastic deformation (SPD) of the resulting metal-matrix composite to produce the bulk nanoscaled structural material. SPD was carried out with equal channel angular pressing (ECAP), which allowed that the material could be subjected to an intense plastic strain through simple shear. Microstructural characteristics of one phase and multiphase material was studied on internally oxidized Cu with 0.4wt.% of Al sample composed of one phase copper-aluminum solid solution in the core and fine dispersed oxide particles in the same matrix in the mantle region. In this manner AFM, X-ray diffraction and Raman spectroscopy were used. Local structures in plastically deformed samples reflect presence of Cu, CuO, Cu2O, Cu4O3 or Al2O3 structural characteristics, depending on type of sample

Tendon injuries around the elbow

The authors describe a technique with a single anterior incision and fixation with an internal button, the Endobutton. The procedure is performed through a 5-cm transverse skin incision, and the tendon is sutured to the Endobutton with 2 number 5 Ethibond sutures. Surgical repair in the depths of the muscular forearm is not required, because the tendon is simply sutured external to the wound. The Endobutton delivers and locks the tendon into a hole in the radial tuberosity. The Endobutton technique was used in 12 patients who were allowed early active mobilization. All were satisfied, returned to activities, and regained grade 5 strength. Average flexion was from 5° to 146° with 81° supination and 80° pronation. No neurovascular complications or synostosis occurred. In cadaveric studies the average distance from the biceps tendon were ulnar artery 6 mm, median nerve 12 mm, and posterior interosseous nerve 18 mm. The average distance from the posterior interosseous nerve to a Steinman pin advanced through the proximal radius was 14 mm. This technique is a safe and effective method of repair of distal biceps tendon avulsion that allows active mobilization with minimal risk of complication (J Shoulder Elbow Surg 2000;9:120-6).</p