Pressure effects on flow and fracture of Be-Al alloys

Abstract

The flow and fracture behavior of Be-Al alloys were determined in tension with different levels of superimposed pressure. The Be-Al alloys were prepared by Brush Wellman, Inc. (Cleveland, OH) from prealloyed powders processed to either a hot isostatically pressed ("hipped") or cold isostatically pressed and extruded condition. Significant effects of pressure on both the flow and ductility have been observed at room temperature, with implications on the formability of these materials. The effects of changes in processing conditions and stress state on the flow and fracture behavior are summarized in addition to both optical and scanning electron microscopy (SEM) examination of the fracture surfaces. Separate other studies on the alloy constituents (e.g., Al and Be) are also reported. The results are also compared to previous works on monolithic materials and composites tested with high pressure.

Effects of Ag, Co, and Ge additions on microstructure and mechanical properties of Be-Al alloy fabricated by investment casting

“…One of the fracture morphologies [Fig. 9(a)] is the brittle zone surrounded by smooth tearing edges in Be phase with different cleavage steps and smooth cleavage planes [5] . The other [Fig.…”

“…A very low mutual solubility of the Be-Al alloy is the barrier to creating alloys with properties substantially different from those of pure metals. Adding elements in Be-Al alloys may lead to some changes in the mechanical properties [5] . Allowing for the basic principles of alloy strengthening, the elements need to have relatively high solid solubility or be capable of forming intermetallic compounds in Be-Al alloys.…”

“…Allowing for the basic principles of alloy strengthening, the elements need to have relatively high solid solubility or be capable of forming intermetallic compounds in Be-Al alloys. Ag, Cr, Cu, Hf, Li, Sc, Zr, and Mg are likely to experience a noticeable solubility in Al; meanwhile, Au, Cu, Fe, Co, Ni, and Pd have a noticeable solubility in Be [5,6] . Many researchers have investigated the effect of adding elements on the properties of Be-Al alloy [7][8][9][10][11] .…”

Experimental Study on Engineering Mechanical Properties of Beryllium

“…Typical value of Be's elongation is usually not exceeding 5%, as a striking contrast, elongation of Aluminum (Al) may reach 20% [2]. On the other hand, Be is a kind of very expensive metal, before the years of 2002, its price had already reached $800 per pound [3]. High defect rate and high price may exert unbearable pressure on enterprise, therefore how to increase Be's elongation now is one of the most significant problems in Be research subjects for scientists and engineers.…”

A Shear Compression Disk Specimen with Controlled Stress Triaxiality under Quasi-Static Loading

“…Among the more common configurations are a circumferentially-notched tensile specimen (e.g., [15][16][17]), notched plane specimens (e.g., [18]), shear and planenotched tensile specimens (e.g., [19]), and a standard tensile specimen exposed to hydrostatic compression in a chamber [20]. These experiments are used to extract a variety of properties including plastic behavior and fracture strain.…”