纳米材料因其自身独特性能而备受关注,从而引发了人们对其进行一系列的研究。采用机械合金化法(MA)和粉末冶金法(PM)制备了纳米尺寸和常规尺寸粉末,通过控制温度和压力等因素,利用真空热压烧结炉将两种不同尺寸的Cu-20Co-20Cr-20Ni粉末...纳米材料因其自身独特性能而备受关注,从而引发了人们对其进行一系列的研究。采用机械合金化法(MA)和粉末冶金法(PM)制备了纳米尺寸和常规尺寸粉末,通过控制温度和压力等因素,利用真空热压烧结炉将两种不同尺寸的Cu-20Co-20Cr-20Ni粉末热压成块体合金,并利用电化学测试技术研究了它们在0.5mol·L^(-1)中性Na Cl溶液中的腐蚀行为以及纳米化对其腐蚀行为的影响。结果表明:当Cu-20Co-20Cr-20Ni合金处于0.5mol·L^(-1) Na Cl腐蚀溶液中时,纳米尺寸Cu-20Co-20Cr-20Ni合金较相应的常规尺寸合金自腐蚀电位发生正移,电荷传递电阻变大,腐蚀电流密度减小。可见,晶粒细化导致Cu-20Co-20Cr-20Ni合金的耐腐蚀性能增强。展开更多
Mo-Cu composite and Cr18-Ni8 stainless steel were brazed with Ni-Cr-P filler metal in a vacuum of 10-4 Pa and a Mo-Cu/Cr18-Ni8 joint was obtained. Microstructure in Mo-Cu/Cr18-Ni8 joint was investigated by field-emiss...Mo-Cu composite and Cr18-Ni8 stainless steel were brazed with Ni-Cr-P filler metal in a vacuum of 10-4 Pa and a Mo-Cu/Cr18-Ni8 joint was obtained. Microstructure in Mo-Cu/Cr18-Ni8 joint was investigated by field-emission scanning electron microscope( FE-SEM) with energy dispersive spectrometer( EDS). Shear strength of Mo-Cu/Cr18-Ni8 lap joint was measured by electromechanical universal testing machine. An excellent Mo-Cu/Cr18-Ni8 joint with a shear strength of 155 MPa was achieved at 980 ℃ for 20 min. Brazed joint was mainly comprised of eutectic structure in the center of brazing seam,matrix structure and lump structure. Ni-Cu( Mo) and Ni-Fe solid solution were at the interface beside Mo-Cu composite and Cr18-Ni8 stainless steel,respectively. Shear fracture exhibited mixed ductile-brittle fracture feature with trans-granular fracture,ductile dimples and tearing edges. Fracture originated from the interface between brazing seam and Mo-Cu composite.展开更多
文摘纳米材料因其自身独特性能而备受关注,从而引发了人们对其进行一系列的研究。采用机械合金化法(MA)和粉末冶金法(PM)制备了纳米尺寸和常规尺寸粉末,通过控制温度和压力等因素,利用真空热压烧结炉将两种不同尺寸的Cu-20Co-20Cr-20Ni粉末热压成块体合金,并利用电化学测试技术研究了它们在0.5mol·L^(-1)中性Na Cl溶液中的腐蚀行为以及纳米化对其腐蚀行为的影响。结果表明:当Cu-20Co-20Cr-20Ni合金处于0.5mol·L^(-1) Na Cl腐蚀溶液中时,纳米尺寸Cu-20Co-20Cr-20Ni合金较相应的常规尺寸合金自腐蚀电位发生正移,电荷传递电阻变大,腐蚀电流密度减小。可见,晶粒细化导致Cu-20Co-20Cr-20Ni合金的耐腐蚀性能增强。
基金supported by Shandong Natural Science Foundation(ZR2015EM040)
文摘Mo-Cu composite and Cr18-Ni8 stainless steel were brazed with Ni-Cr-P filler metal in a vacuum of 10-4 Pa and a Mo-Cu/Cr18-Ni8 joint was obtained. Microstructure in Mo-Cu/Cr18-Ni8 joint was investigated by field-emission scanning electron microscope( FE-SEM) with energy dispersive spectrometer( EDS). Shear strength of Mo-Cu/Cr18-Ni8 lap joint was measured by electromechanical universal testing machine. An excellent Mo-Cu/Cr18-Ni8 joint with a shear strength of 155 MPa was achieved at 980 ℃ for 20 min. Brazed joint was mainly comprised of eutectic structure in the center of brazing seam,matrix structure and lump structure. Ni-Cu( Mo) and Ni-Fe solid solution were at the interface beside Mo-Cu composite and Cr18-Ni8 stainless steel,respectively. Shear fracture exhibited mixed ductile-brittle fracture feature with trans-granular fracture,ductile dimples and tearing edges. Fracture originated from the interface between brazing seam and Mo-Cu composite.
