Patent Number: 047055774
Section: description

EXAMPLE 7.6 g uranium powder having an average particle size of 30 /.mu. and 5.6 g aluminum powder having an average particle size of 50 /.mu. were mixed for more than an hour in a tumbling mixer equipped with plastic or ceramics inserts and rotating at 70 rpm. Due to the pyrophorosity of the U powder the work was performed in a gas purification box. The powder mixture was then pressed at 300 MPa and room temperature into a plate of 2.5 mm thickness. Thereafter, the pressed body was inserted into an Al frame together with Al bottom and cover foils (sheaths, each with a thickness of 2.4 mm) and was welded to the frame in vacuo in a welding box. Rolling took place in three passes, a reduction in thickness of 1 mm of the combination of plate, frame and foils was realized in each of the first and second passes and an additional reduction in thickness of 15% was realized in the third roll pass. Thereafter the thickness of the plate was 1.3 mm. The rolling temperature was near 800.degree..+-.25 K., with the picture frame being heated for about 10 minutes before the first rolling pass. After the third rolling pass, the plate together with the frame was placed onto a sheet of molybdenum, was covered at its upper surface with a further sheet of molybdenum. In a steel clamping device the two molybdenum sheets were then fixed to the steel plate of the device and the said combination was subjected to a heat treatment of 800.degree..+-.25 K. for 100 hours. Radiographs and glow images of the plate indicated a uniform and homogeneous macroscopic structure without the formation of macroscopic cracks or bubbles. It will be understood that the above description of the present invention is susceptible to various modifications, changes, and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of appended claims.