电子束选区熔化(selective electron beam melting,SEBM)增材制造技术在制备具有低室温塑性的金属间化合物材料方面具有独特的技术优势,采用该技术制备的TiAl合金部件已经在先进航空发动机获得成功应用。本研究以Ar气雾化的Ti-48Al-2Cr-...电子束选区熔化(selective electron beam melting,SEBM)增材制造技术在制备具有低室温塑性的金属间化合物材料方面具有独特的技术优势,采用该技术制备的TiAl合金部件已经在先进航空发动机获得成功应用。本研究以Ar气雾化的Ti-48Al-2Cr-2Nb预合金粉末为原料,采用SEBM成功制备出TiAl合金低压涡轮导向叶片模拟件,并对叶片的抗热冲击性能及随炉试棒的室温拉伸性能进行评价。结果表明:SEBM制备的TiAl合金经热处理后室温抗拉强度可达515 MPa,断后伸长率为1.13%;TiAl合金叶片模拟件经700℃水淬热冲击120次后结构完整,经900℃水淬热冲击6次后叶身部分出现垂直于径向的裂纹;结合裂纹扩展路径和裂纹断口分析,确定叶片部件在热冲击条件下失效的主要机制是表面较大粗糙度引起的应力集中。展开更多
With types of in-house-synthesized multi-walled carbon nanotubes (CNTs);highly active CNT-promoted Co-Cu catalysts,symbolized as CoiCuj-x%CNTs (mass fraction) were prepared by the co-precipitation method from nitrate ...With types of in-house-synthesized multi-walled carbon nanotubes (CNTs);highly active CNT-promoted Co-Cu catalysts,symbolized as CoiCuj-x%CNTs (mass fraction) were prepared by the co-precipitation method from nitrate salts of the corresponding metallic components.Their catalytic performances for the cinnamyl alcohol synthesis from the hydrogenation of cinnamaldehyde were studied and compared with the corresponding CNT-free coprecipitated catalyst of CoiCuj mixed oxide.It was shown that the appropriate incorporation of a minor amount of the CNTs into CoiCuj oxide could significantly increase the catalytic activity for cinnamyl alcohol synthesis.Under the pressure of 5.0 MPa,the highest yield of cinnamyl alcohol reaches 94.4% with selectivity of 98.7% for the catalyst Co_(2)-Cu1-10.0%CNTs.The addition of an appropriate amount of CNT can promote the highly dispersed catalyst and promote the recovery of the catalyst.The results show that carbon nanotube is an excellent accelerator,and its properties for unique hydrogen absorption play important roles in promoting the synthesis of cinnamyl alcohol.展开更多
文摘电子束选区熔化(selective electron beam melting,SEBM)增材制造技术在制备具有低室温塑性的金属间化合物材料方面具有独特的技术优势,采用该技术制备的TiAl合金部件已经在先进航空发动机获得成功应用。本研究以Ar气雾化的Ti-48Al-2Cr-2Nb预合金粉末为原料,采用SEBM成功制备出TiAl合金低压涡轮导向叶片模拟件,并对叶片的抗热冲击性能及随炉试棒的室温拉伸性能进行评价。结果表明:SEBM制备的TiAl合金经热处理后室温抗拉强度可达515 MPa,断后伸长率为1.13%;TiAl合金叶片模拟件经700℃水淬热冲击120次后结构完整,经900℃水淬热冲击6次后叶身部分出现垂直于径向的裂纹;结合裂纹扩展路径和裂纹断口分析,确定叶片部件在热冲击条件下失效的主要机制是表面较大粗糙度引起的应力集中。
基金supported by the National Natural Science Foundation of China (No.21773196).
文摘With types of in-house-synthesized multi-walled carbon nanotubes (CNTs);highly active CNT-promoted Co-Cu catalysts,symbolized as CoiCuj-x%CNTs (mass fraction) were prepared by the co-precipitation method from nitrate salts of the corresponding metallic components.Their catalytic performances for the cinnamyl alcohol synthesis from the hydrogenation of cinnamaldehyde were studied and compared with the corresponding CNT-free coprecipitated catalyst of CoiCuj mixed oxide.It was shown that the appropriate incorporation of a minor amount of the CNTs into CoiCuj oxide could significantly increase the catalytic activity for cinnamyl alcohol synthesis.Under the pressure of 5.0 MPa,the highest yield of cinnamyl alcohol reaches 94.4% with selectivity of 98.7% for the catalyst Co_(2)-Cu1-10.0%CNTs.The addition of an appropriate amount of CNT can promote the highly dispersed catalyst and promote the recovery of the catalyst.The results show that carbon nanotube is an excellent accelerator,and its properties for unique hydrogen absorption play important roles in promoting the synthesis of cinnamyl alcohol.
