Superplasticity of beryllium

Beryllium is a metal having unique physicomechanical properties, including a record specific rigidity, but it undergoes cold and red brittleness. As a result of long-term investigations, we were the first to manufacture high-purity fine-grained beryllium, which has the room-temperature plasticity that is higher than that of commercial-purity powdered beryllium by an order of magnitude and exhibits superplastic flow at elevated temperatures. In this review, we summarize the results of the long-term study of the superplastic flow of beryllium and the mechanisms of high-temperature deformation.     

Immunotoxicity of beryllium

The patient, a 35-year-old woman, had been diagnosed as SLE since she developed butterfly rash, arthritis and hair loss with positive antinuclear antibody, anti-DNA antibody, and LE cells in 1989, and treated with daily 20 mg prednisolone (PSL). She had been suffering from nausea, vomiting and waterly diarrhea since 1992. In June 1995, she noted pollakisuria and sense of residual urine, followed by dysuria and nocturia in October. She was admitted to our hospital in January 1996 with progressive gastrointestinal and urinary symptoms. Computerized tomography (CT) depicted thickening of the wall of intestine and bladder, diminished volume of bladder, and bilateral hydronephrosis and hydroureter. Biopsy of the bladder revealed erosion of mucosa and moderate infiltration with inflammatory cells. The diagnosis of lupus cystitis and peritonitis was made and she was initially given intravenous methylprednisolon pulse therapy (500 mg/day) for 3 days, and then switched to 100 mg of daily intravenous PSL. She responded partially to this regimen, but gradually developed gastrointestinal and urinary symptoms again when PSL was tapered down to 70 mg/day. Therefore, monthly intravenous cyclophosuphamide pulse therapy was started. With this therapy, her bladder and bowel symptoms improved, and then the thickness of her bladder and intestinal wall, and the bladder volume normalized. Five months after institution of therapy, PSL was successfully tapered down to 30 mg/day and she was discharged. Intravenous cyclophosphamidepulse therapy is a choice of treatment for steroid-resistant lupus cystitis and peritonitis.     

Kroll process beryllium

High-purity beryllium metal was prepared on a laboratory scale by Kroll process procedures in which sodium was used as a reductant. Crude beryllium chloride, purchased from commercial sources, was purified by vacuum sublimation and fused-salt scrubbing. Purified beryllium chloride was vaporized and reacted at a controlled rate with molten sodium at temperatures ranging from 650° to 750°C to form beryllium sponge. Excess metal reductant and byproduct salt were removed from the sponge metal by vacuum distillation. Beryllium sponge metal was wet ball milled to ?200 or ?400 mesh powders. Beryllium powder metal, subsequently consolidated by isostatic pressing, was hot extruded and machined into tensile specimens for evaluation of mechanical properties. Evaluation indicates that the beryllium described in this study is of higher purity than comparable commercial grades of metal; also it is more ductile but has somewhat lower strength. The overall process appears to have an excellent potential from an economic standpoint.