THE METALLURGY OF YTTRIUM AND THE RARE EARTH METALS PARTⅡ MECHANICAL PROPERTIES

摘要

Study of the mechanical properties of rare earth metals was continued. Tensile, compression, fatigue, and impact properties were determined. Evaluation of the metals was extended to include hot and cold working characteristics, and studies were made of alloy systems predicted to have improved mechanical properties.nCast yttrium, dysprosium, and erbium can be cold worked to improve mechanical properties. All are easily swaged at 980℃ (l800°F). The resulting structures are uniform and dense, and the properties are improved over the cast condition. Tensile properties are quite comparable when the metals are in the same condition. Ductility (as measured by reduction of area) was somewhat limited for the cast structures, but was improved by working. The cast rare earth metals are notch sensitive. The fatigue properties follow the normal pattern of increased life with decreased maximum applied load. Extrapolated S-N curves indicate fatigue endurance limits in the order of 40 - 50％ of the corresponding ultimate tensile strengths.