【摘要】 分别用纳米颗粒Cr（平均尺寸62 nm）,Al（平均尺寸85nm）和微米颗粒Cr和Al（平均尺寸3μm）复合电沉积制备Ni-11Cr-3Al纳米复合镀层（ENC）和Ni-11Cr-7Al微米复国镀层（EMC）。纳米颗粒的复合使ENC Ni-11Cr-3Al比EMC Ni-11Cr-7Al的颗粒分布更加均匀,颗粒间距减小近25倍。900℃,24h恒温氧化实验表明,ENC Ni-11Cr-3Al与EMC Ni-11Cr-7Al相比氧化速率显著降低。这是由于其快速形成一层连续、致密的Cr₂O₃膜,进而促进其下Al₂O₃膜的快速形成所致。更多还原

【Abstract】 Two electrodeposited Ni matrix composite coatings were prepared;one was Ni-11Cr-3Al（by mass%） prepared using nano-sized particles of Cr and Al and the other was Ni-11Cr-7Al composite prepared using micron-sized particles of Cr and Al.Compared with the electrodeposited micron-composite（EMC） Ni-HCr -7Al,the electrodeposited nanocomposite（ENC） Ni-11Cr-3Al exhibited much homogeneous distribution of Cr and Al particles,because of an approximately 25-fold decrease in interparticle spacing.The significantly shorter interparticle spacing allowed the ENC Ni-11Cr-3Al to grow a continuous Cr₂O₃ layer first and then an Al₂O₃ layer underneath during a very short stage of oxidation.This is the fundamental reason for the result that the ENC,although it had a lower content of Al,was oxidized slower than the EMC Ni-11Cr-7Al during oxidation in air at 900℃.The size effect of the Cr and Al particles on the oxidation behavior of the electrodeposited Ni-Cr-Al composite coatings is discussed in detail.更多还原