在恒定的法向载荷下,使用Rockwell C 120°金刚石压头对聚碳酸酯(PC)、熔融石英、紫铜和镁合金AZ31进行微米划痕测试,研究滑动速度对试样划痕响应的影响.压入深度小于压头的球锥转变深度,确保仅有压头顶端的圆球部分与试样接触.结...在恒定的法向载荷下,使用Rockwell C 120°金刚石压头对聚碳酸酯(PC)、熔融石英、紫铜和镁合金AZ31进行微米划痕测试,研究滑动速度对试样划痕响应的影响.压入深度小于压头的球锥转变深度,确保仅有压头顶端的圆球部分与试样接触.结果表明:随着滑动速度的增加,压入深度、残余深度和划痕沟槽的宽度均非线性减小,划痕硬度和弹性恢复率均非线性增大;PC和紫铜的划痕摩擦系数先增大后减小,PC的黏弹性行为对其摩擦响应有显著影响;熔融石英的划痕摩擦系数先增大后减小,最后趋于稳定;镁合金AZ31的划痕摩擦系数先减小后增大.熔融石英、紫铜和镁合金AZ31的划痕摩擦系数的变化趋势可通过几何接触模型进行解释.展开更多
通过Rockwell C 120°金刚石压头对16种金属材料进行微米划痕测试,研究渐进法向力对材料划痕响应的影响。结果表明:随着法向力从5 mN线性增大到30 N,压入深度和残余深度均线性增加;弹性回复率先迅速增大,然后趋于一个常数。当压入...通过Rockwell C 120°金刚石压头对16种金属材料进行微米划痕测试,研究渐进法向力对材料划痕响应的影响。结果表明:随着法向力从5 mN线性增大到30 N,压入深度和残余深度均线性增加;弹性回复率先迅速增大,然后趋于一个常数。当压入深度小于压头的球锥转变深度时,仅有压头顶端的圆球与材料接触,残余划痕宽度非线性增加;当压头的圆锥部分与材料接触时,残余划痕宽度线性增大。稳定弹性回复率和划痕硬度随屈服强度的增加而线性增大。纯Mo、纯W和40Cr的划痕摩擦系数随法向力的增加始终非线性增大,其余金属的划痕摩擦系数先非线性增加,之后趋于稳定;划痕摩擦系数的变化趋势可通过几何接触模型进行解释。在较大法向力下,QT500的摩擦机制中黏着摩擦和犁沟摩擦起到几乎相同的作用,其余材料的摩擦机制主要为犁沟摩擦。稳定划痕摩擦系数随稳定划痕硬度及其与弹性模量比值的增加而线性减小。展开更多
In order to improve the corrosion resistance of carbon steel,Hastelloy coatings were prepared on E235steel substrate by ahigh power diode laser with laser scanning speeds of6and12mm/s,respectively.The interface betwee...In order to improve the corrosion resistance of carbon steel,Hastelloy coatings were prepared on E235steel substrate by ahigh power diode laser with laser scanning speeds of6and12mm/s,respectively.The interface between the coating and substratewas firstly exposed by dissolving off the substrate.Its microstructure,composition and mechanical properties were systemicallystudied.Special“edges”along the grain boundary were found at coating/substrate interface.These“edges”consisted of intergranularcorrosion area and real grain boundary.The interface of coating mainly displayed austenite structure ascribed to the rapidsolidification as well as the dilution of Ni during preparation.Additionally,Hastelloy coating and its interface prepared at the speedof12mm/s showed higher hardness than that prepared at the speed of6mm/s.Grain boundaries had higher friction coefficient thangrains at both coating/substrate interfaces.Moreover,the interface at higher laser scanning speed exhibited smaller grains,lowerdilution rates of Ni and Fe as well as a better tribological property.展开更多
文摘在恒定的法向载荷下,使用Rockwell C 120°金刚石压头对聚碳酸酯(PC)、熔融石英、紫铜和镁合金AZ31进行微米划痕测试,研究滑动速度对试样划痕响应的影响.压入深度小于压头的球锥转变深度,确保仅有压头顶端的圆球部分与试样接触.结果表明:随着滑动速度的增加,压入深度、残余深度和划痕沟槽的宽度均非线性减小,划痕硬度和弹性恢复率均非线性增大;PC和紫铜的划痕摩擦系数先增大后减小,PC的黏弹性行为对其摩擦响应有显著影响;熔融石英的划痕摩擦系数先增大后减小,最后趋于稳定;镁合金AZ31的划痕摩擦系数先减小后增大.熔融石英、紫铜和镁合金AZ31的划痕摩擦系数的变化趋势可通过几何接触模型进行解释.
文摘通过Rockwell C 120°金刚石压头对16种金属材料进行微米划痕测试,研究渐进法向力对材料划痕响应的影响。结果表明:随着法向力从5 mN线性增大到30 N,压入深度和残余深度均线性增加;弹性回复率先迅速增大,然后趋于一个常数。当压入深度小于压头的球锥转变深度时,仅有压头顶端的圆球与材料接触,残余划痕宽度非线性增加;当压头的圆锥部分与材料接触时,残余划痕宽度线性增大。稳定弹性回复率和划痕硬度随屈服强度的增加而线性增大。纯Mo、纯W和40Cr的划痕摩擦系数随法向力的增加始终非线性增大,其余金属的划痕摩擦系数先非线性增加,之后趋于稳定;划痕摩擦系数的变化趋势可通过几何接触模型进行解释。在较大法向力下,QT500的摩擦机制中黏着摩擦和犁沟摩擦起到几乎相同的作用,其余材料的摩擦机制主要为犁沟摩擦。稳定划痕摩擦系数随稳定划痕硬度及其与弹性模量比值的增加而线性减小。
基金Project supported by the New Staff Research Start-up Fund and the Innovation Fund(School of Materials Science and Engineering) of Southwest Petroleum University,China
文摘In order to improve the corrosion resistance of carbon steel,Hastelloy coatings were prepared on E235steel substrate by ahigh power diode laser with laser scanning speeds of6and12mm/s,respectively.The interface between the coating and substratewas firstly exposed by dissolving off the substrate.Its microstructure,composition and mechanical properties were systemicallystudied.Special“edges”along the grain boundary were found at coating/substrate interface.These“edges”consisted of intergranularcorrosion area and real grain boundary.The interface of coating mainly displayed austenite structure ascribed to the rapidsolidification as well as the dilution of Ni during preparation.Additionally,Hastelloy coating and its interface prepared at the speedof12mm/s showed higher hardness than that prepared at the speed of6mm/s.Grain boundaries had higher friction coefficient thangrains at both coating/substrate interfaces.Moreover,the interface at higher laser scanning speed exhibited smaller grains,lowerdilution rates of Ni and Fe as well as a better tribological property.
