激光诱导自蔓延Ni-Al合金组织性能及掺杂B的影响  

Influence of B on microstructure and properties of NiAl alloy prepared by laser-induced self-propagating reaction synthesis

作　　者：李刚[1] 金红梅[1] 于君娜[1] 唐海鹏[1] 

机构地区：[1]辽宁工程技术大学材料科学与工程学院,辽宁阜新123000

出　　处：《兵器材料科学与工程》2012年第4期8-11,共4页Ordnance Material Science and Engineering

基　　金：辽宁省科学事业公益研究基金计划项目资助

摘　　要：在Ni14.3Al5.7中掺杂原子数分数为1.86%的B,将原始粉末压制成坯。采用不同激光点火功率对压坯进行激光诱导自蔓延烧结,利用SEM、XRD及硬度、磨损、耐蚀性测试表征手段,分析研究烧结合金的微观组织结构及宏观性能。结果表明:未添加B,烧结合金物相为Ni3Al、NiAl、Al2O3,合金组织呈网状分布;掺杂B后,烧结产物为Ni3Al、NiAl、Al4B2O9、Al2O3,对产物组织形貌影响较小。当烧结功率为700 W,烧结合金的显微硬度达到381.27HV,维钝电流为0.253 mA/mm2;功率为1 100 W,相对密度达89.3%;功率为900 W,耐磨性最佳,相对质量损失为0.24%。在相同烧结功率下,B提升了烧结合金的相对密度、硬度,但耐磨性、耐蚀性能有所下降。Ni14.3Al5.7 alloy powder blended with 1.86% （atomic fraction） boron powder was pressed and prepared by laser ignition induced SHS at different laser power. By means of SEM, XRD, hardness test, abrasion test and corrosion test, the microstructure and macroscopic properties of the sintered alloy were studied. The experimental results show that without adding boron powder, the product phases of the sintered alloy are Ni3Al,NiAl and Al2O3, and the structures of the sintered alloy distribute as net. When the laser power is 700 W, the micro hardness of the sintered alloy reaches the maximum of 381.27HV and the passivation current density is 0.253 mA/mm2; When the laser power is 1 100 W, the relative density of the sintered alloy reaches the maximum, which is 89.3% ; When the laser power is 900 W, the relative wear rate of the sintered alloy is the lowest of 0.24%. After adding boron powder, the product phases of the sintered alloy are Ni3Al, NiAl, Al4B2O9 and Al2O3, and there is little effect on the microstructure and morphology. With the same laser power, the addition of boron powder can improve the hardness and relative density of the sintered alloy, but reduce the abrasion resistance and corrosion resistance.

关 键 词：激光烧结 自蔓延合成 微观组织 宏观性能 

分 类 号：TF124[冶金工程—粉末冶金]