摘要
将220℃退火的LF6M铝合金试样在320℃重新进行热处理,观察了220℃退火试样和320℃退火试样的金相组织和晶界显微结构,对比研究了2种退火状态的LF6M铝合金在硫酸溶液中的阳极极化行为,并观察了2种基材上硫酸阳极氧化膜的微观结构。结果表明:220℃退火试样中的β相沿晶界集中分布,在320℃重新热处理后,β相在晶界及晶内均匀分布,晶界腐蚀敏感性减弱;β相粒子在阳极氧化过程中优先溶解,会造成氧化膜中的微小孔洞缺陷,因此220℃退火试样阳极氧化时,氧化膜中因孔洞缺陷的集中形成了更大的局部缺陷,防护性能下降,而320℃重新热处理可以改善这一状况。
LF6M aluminum alloys annealed at 220 ℃ were retreated at 320 ℃.The influence of annealing temperature on microstructure of LF6M aluminum alloy substrates and anodic oxide coatings formed in sulfuric acid solution was studied.The anodic behavior of LF6M alloys in sulfuric acid solution was researched using potentiodynamic polarization curves.β-phase particles concentrated in grain boundaries of LF6M alloys annealed at 220 ℃,but distributed equably in grains and boundaries for alloys treated at 320 ℃.β-phase particles dissoluted preferentially during anodic oxidation and cavities formed in the films on both annealing condition.For LF6M alloys annealed at 220 ℃,larger cavities were caused by preferential dissolution of β-phase particles along grain boundaries,which lead to the decline of the oxide films＇ corrosion resistance.However,retreatment at 320 ℃ could restrain the formation of larger cavities in the oxide films.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2010年第6期33-35,86,共4页
Surface Technology
关键词
LF6M铝合金
退火温度
阳极氧化
Β相
LF6M aluminum alloy
annealing temperature
anodic oxide
β-particles
