【摘要】 为研究Fe-Cu二元合金时效硬化问题,采用小角中子散射(SANS)并结合电子显微镜技术研究了Fe-0.6Cu二元合金热时效过程Cu元素脱溶分解对硬度及微观组织变化规律的影响。结果表明,未时效基体晶界基本为三维形态,晶界处共格程度较低,基体由于固溶强化,硬度较大;时效初期Cu元素以二维形态在晶界处局部聚集,晶界处共格程度增大,硬度减小;继续时效晶界处析出大量富Cu相,晶界处共格程度减小,硬度增大;到达时效峰值附近富Cu析出相由二维形态转变为三维结构,晶界两边的Cu元素聚集程度降低,共格程度增大,硬度减小。时效过程中,脱溶分解驱动力越大,晶界处富Cu析出相从二维形态向三维结构转变的速度更快。更多还原

【Abstract】 In order to examine the age-hardening of Fe-Cu binary alloy,the effect of dissolution and decomposition of Cu element on hardness and microstructure of Fe-0.6 Cu binary alloy during thermal aging was studied by small angle neutron scattering(SANS)and electron microscope.The results show that the grain boundary of the unaged matrix is basically three-dimensional,the degree of coherence at the grain boundary is low,and the hardness of the matrix is higher due to solution strengthening,and at the initial stage of aging,Cu elements are locally aggregated at the grain boundary in two-dimensional form,the degree of coherence at the grain boundary increases and the hardness decreases,and a large number of Cu-rich phases precipitate at the grain boundary after continuous aging,the coherence degree at the grain boundary decreases and the hardness increases.Near the aging peak,the Cu-rich precipitates change from two-dimensional morphology to three-dimensional structure,the aggregation degree of Cu elements on both sides of the grain boundary decreases,the degree of coherence increases,and the hardness decreases.During the aging process,the greater the driving force of dissolution and decomposition,the faster the transformation of the Cu-rich precipitates at the grain boundary from two-dimensional morphology to three-dimensional structure.更多还原