Electrodeposition of NiCoCr-Al_2O_3 Foam Alloy and its Antioxidation at High Temperatures

NiCoCr-Al_2O_3 foam alloy was electrodeposited,the effects of the composition of solution on the properties of foam alloy were studied.The contents of Cr and Al_2O_3 in the alloy increase with the increases of concentrations of CrCl_3·6H_2O and Al_2O_3 in bath,the alloy surface changes to black when Cr in the alloy is over 6.8%;the alloy becomes fragile when Al_2O_3 in the alloy is over 8.1%.It is foudn that only when the temperature was higher than 852.37℃did the phase which is propitious to antioxidation at high temperatures appear.The effects of treatment temperature on the antioxidation of the alloy at high temperatures were investi- gated,the mass gain was the lowest after the alloy was treated at 1200℃.The effects of chromium and aluminium contents on the antioxidation of the alloy at high temperatures were also studied,the antioxidation of the alloy was improved with increasing the amount of Cr and Al_2O_3 in the alloy.It is found that Al_2O_3 promo- ted the antioxidation of the alloy.