摘要
采用同步送粉激光熔覆技术分别将Ni基和Co基合金粉末熔覆在结晶器铜板表面,制备出组织均匀无缺陷且与基体结合良好的熔覆层。研究表明:Ni基熔覆层平均显微硬度为672.3HV0.5,Co基熔覆层平均显微硬度为604HV0.5,分别约为目前广泛使用的Ni基电镀层的2.6倍和2.4倍,是铜基体的6.5倍和6.2倍。虽然目前结晶器铜板表面强化主要采用电镀技术,但电镀层在较高的工作温度下会出现软化现象。热冲击更会使镀层组织变粗,镀层硬度下降更加显著,并伴有间隙和气孔等缺陷,但对激光熔覆层性能的影响却很小。因此,激光熔覆技术是结晶器铜板表面强化的一种有效方法,可替代电镀工艺。
Ni based alloy and. Co based alloy have been successfully cladded on the crystallizer Cu alloy by powder fed laser cladding, whose microstructure are fine, dense and defect-free. The metal- lurgical bonding layer is formed at the bottom of the laser cladding layer. It is found that the average micro-hardness of Ni based and Co based cladding layer separately is 672.3 HV0.s and 604 HV0.5 which is about 2.6 times and 2.4 times of Ni based electroplated layer, about 6.5 times and 6.2 times of Cu substrate. Although electroplating is the main strengthening technique on the copper crystallizer sur- face, electroplated layer micro-hardness will become, low with the temperature becoming high. Through heat shock test the electroplated layer microstructure become large and its micro-hardness also become much lower than before, while it is little influence on laser cladding laser. So laser cladding is the one of effective methods of surface strengthening on the copper crystallizer, and can replace electro- plating technique.
出处
《电加工与模具》
2013年第1期31-36,共6页
Electromachining & Mould
基金
国家自然科学基金资助项目(51275303)
关键词
结晶器铜板
激光熔覆
电镀层
热冲击
crystallizer Cu board
laser cladding
electroplating coating
thermal shock
