The effect of trace element B on microstructure of directionally slidified new type Co-base superalloy is studied systematically in this paper.It is found that the addition of B makes the incipient melting temperature...The effect of trace element B on microstructure of directionally slidified new type Co-base superalloy is studied systematically in this paper.It is found that the addition of B makes the incipient melting temperature of the alloy decline remarkably.Compared withthe alloy having a boron contenl of 0.05%,the incipient melting temperature of the alloywith 0.7% B decreases by 197℃.The primary and secondary dendrite arm spacings in-crease and the volume fraction of interdendritic carbides with fine microstructure becomesbigger with the enhancement of boron content.When the alloy is with 0.7wt%B,M<sub>3</sub>B<sub>2</sub> precipitates in the interdendrites.展开更多
采用单向硼/环氧复合材料补片真空袋压工艺单面修复含中心裂纹不同厚度铝合金板,测试了修复试件的疲劳性能,从疲劳寿命、疲劳裂纹扩展速率和裂纹扩展纹线考察不同厚度铝合金板修复后疲劳性能的差异。结果表明:硼/环氧补片胶接修复后,铝...采用单向硼/环氧复合材料补片真空袋压工艺单面修复含中心裂纹不同厚度铝合金板,测试了修复试件的疲劳性能,从疲劳寿命、疲劳裂纹扩展速率和裂纹扩展纹线考察不同厚度铝合金板修复后疲劳性能的差异。结果表明:硼/环氧补片胶接修复后,铝合金板的疲劳寿命大幅度提高,且疲劳寿命提高幅度随铝合金板厚度增大而降低。厚度为1.76 mm、5.20 mm和10.20 mm 3种铝合金板修复试件的疲劳寿命分别是未修复试件的22.30倍、12.84倍和8.40倍。厚度为1.76 mm铝合金板修复试件在铝合金板完全断裂后还能继续承担疲劳载荷,而厚度为5.20 mm和10.20 mm 2种铝合金板修复试件在铝合金板断裂后完全破坏。裂纹扩展速率和归一化裂纹长度差均随铝合金板厚度增大而增大。展开更多
文摘The effect of trace element B on microstructure of directionally slidified new type Co-base superalloy is studied systematically in this paper.It is found that the addition of B makes the incipient melting temperature of the alloy decline remarkably.Compared withthe alloy having a boron contenl of 0.05%,the incipient melting temperature of the alloywith 0.7% B decreases by 197℃.The primary and secondary dendrite arm spacings in-crease and the volume fraction of interdendritic carbides with fine microstructure becomesbigger with the enhancement of boron content.When the alloy is with 0.7wt%B,M<sub>3</sub>B<sub>2</sub> precipitates in the interdendrites.
文摘采用单向硼/环氧复合材料补片真空袋压工艺单面修复含中心裂纹不同厚度铝合金板,测试了修复试件的疲劳性能,从疲劳寿命、疲劳裂纹扩展速率和裂纹扩展纹线考察不同厚度铝合金板修复后疲劳性能的差异。结果表明:硼/环氧补片胶接修复后,铝合金板的疲劳寿命大幅度提高,且疲劳寿命提高幅度随铝合金板厚度增大而降低。厚度为1.76 mm、5.20 mm和10.20 mm 3种铝合金板修复试件的疲劳寿命分别是未修复试件的22.30倍、12.84倍和8.40倍。厚度为1.76 mm铝合金板修复试件在铝合金板完全断裂后还能继续承担疲劳载荷,而厚度为5.20 mm和10.20 mm 2种铝合金板修复试件在铝合金板断裂后完全破坏。裂纹扩展速率和归一化裂纹长度差均随铝合金板厚度增大而增大。