The thermal stability of nanocrystalline Ni-Co-Fe-P coatings with phosphorus content up to 3.38 wt% prepared by pulsed electrodepostion was studied using XRD, TEM and DSC. It is found that multi-component alloying doe...The thermal stability of nanocrystalline Ni-Co-Fe-P coatings with phosphorus content up to 3.38 wt% prepared by pulsed electrodepostion was studied using XRD, TEM and DSC. It is found that multi-component alloying does improve the thermal stability of nanocrystalline coatings due to a “solution drag effect”. For nanocrystalline Ni-40.41%Co-6.16%Fe-1.63%P coating, P-atoms segregate the grain boundaries during annealing which leads to a higher thermal stability. While due to the higher initial P-concentration in Ni-30.1%Co-2.15%Fe-3.38%P, saturation of P and precipitation occurs earlier leading to a slightly lower stability.展开更多
Cr_2O_3-forming ferritic stainless steels have been widely explored as intermediate temperature solid oxide fuel cells(SOFCs) interconnects.However,the evaporation of chromia scale might migrate to and poison the cath...Cr_2O_3-forming ferritic stainless steels have been widely explored as intermediate temperature solid oxide fuel cells(SOFCs) interconnects.However,the evaporation of chromia scale might migrate to and poison the cathode,leading to degradation of the cell performance.In this study,Ni-Co-Fe-P coatings were deposited on the ferritic stainless steel by means of a cost-effective technique of electroless method.They are expected to be converted into(Ni,Co,Fe)_3O_4 spinel with a high electrical conductivity and CTE match with stainless steel,which can block the evaporation of chromia formed on steel substrate exposed to the cathode environment of the SOFC. The effects of pH,mass ratio of FeSO_4/(FeSO_4 + NiSO_4 + CoSO_4) and temperature of solution on the deposition rate,compositions,surface morphologies and structures of the Ni-Co-Fe-P coatings were investigated.The results indicated that the deposition rate increased with increasing pH when pH was lower than 9 and then reduced when pH was higher than 9.The deposition rate increased with increasing temperature when temperature was lower than 80℃and then decreased when temperature was higher than 80℃.The deposition rate decreased with the increase in mass ratio of FeSO_4/(NiSO_4 + CoSO_4 + FeSO_4).The coatings consisted of Ni,Co,Fe and P.The phase structure of the coating was amorphous.展开更多
文摘The thermal stability of nanocrystalline Ni-Co-Fe-P coatings with phosphorus content up to 3.38 wt% prepared by pulsed electrodepostion was studied using XRD, TEM and DSC. It is found that multi-component alloying does improve the thermal stability of nanocrystalline coatings due to a “solution drag effect”. For nanocrystalline Ni-40.41%Co-6.16%Fe-1.63%P coating, P-atoms segregate the grain boundaries during annealing which leads to a higher thermal stability. While due to the higher initial P-concentration in Ni-30.1%Co-2.15%Fe-3.38%P, saturation of P and precipitation occurs earlier leading to a slightly lower stability.
文摘Cr_2O_3-forming ferritic stainless steels have been widely explored as intermediate temperature solid oxide fuel cells(SOFCs) interconnects.However,the evaporation of chromia scale might migrate to and poison the cathode,leading to degradation of the cell performance.In this study,Ni-Co-Fe-P coatings were deposited on the ferritic stainless steel by means of a cost-effective technique of electroless method.They are expected to be converted into(Ni,Co,Fe)_3O_4 spinel with a high electrical conductivity and CTE match with stainless steel,which can block the evaporation of chromia formed on steel substrate exposed to the cathode environment of the SOFC. The effects of pH,mass ratio of FeSO_4/(FeSO_4 + NiSO_4 + CoSO_4) and temperature of solution on the deposition rate,compositions,surface morphologies and structures of the Ni-Co-Fe-P coatings were investigated.The results indicated that the deposition rate increased with increasing pH when pH was lower than 9 and then reduced when pH was higher than 9.The deposition rate increased with increasing temperature when temperature was lower than 80℃and then decreased when temperature was higher than 80℃.The deposition rate decreased with the increase in mass ratio of FeSO_4/(NiSO_4 + CoSO_4 + FeSO_4).The coatings consisted of Ni,Co,Fe and P.The phase structure of the coating was amorphous.
