Effect of Spark Plasma Sintering Temperature on Electrochemical Properties of La_(0. 82)Mg_(0. 18)Ni_(3. 50)Co_(0. 15) Alloy  

作　　者：Xiao-ping DONG Yan-rong PANG Li-ying YANG Qing WANG Zhi-yuan LI 

机构地区：[1]Department of Mechanics,Hebei University

出　　处：《Journal of Iron and Steel Research International》2016年第5期459-465,共7页

基　　金：Item Sponsored by National Natural Science Foundation of China(51371094,51161015)

摘　　要：Electrochemical properties of La_（0. 82）Mg_（0. 18）Ni_（3. 50）Co_（0. 15） alloys synthesized by spark plasma sintering（ SPS） were investigated based on the electrochemical measurements,physical parameters and microstructure observation. The sintering behavior of La_（0. 82）Mg_（0. 18）Ni_（3. 50）Co_（0. 15） alloys at the temperatures of 900,950 and 1 000 ℃ is characterized by four stages,i. e.,initial slight shrinkage,expansion,abrupt shrinkage and slight expansion. The maximum shrinkage displacement increases with increasing sintering temperature. All of the alloys consist of（ La,Mg）_2（ Ni,Co）_7 phase; additionally,temperatures of 900 and 950 ℃ are beneficial to the formation of（ La,Mg）（ Ni,Co）_3 phase,whereas the LaNi_5 phase is easy to form in the alloy synthesized by SPS at 1 000 ℃. The electrochemical measurements indicate an evident change of the electrochemical performance of the alloys associated with increasing the sintering temperature. The discharge capacity of the alloys first increases and then decreases as sintering temperature rises,whereas their cycle stability clearly grows all the time.Furthermore,the charging-discharging potential difference and discharging efficiency both demonstrate that the electrochemical properties of the alloy electrodes first augment and then decline with increasing sintering temperature.Electrochemical properties of La_（0. 82）Mg_（0. 18）Ni_（3. 50）Co_（0. 15） alloys synthesized by spark plasma sintering（ SPS） were investigated based on the electrochemical measurements,physical parameters and microstructure observation. The sintering behavior of La_（0. 82）Mg_（0. 18）Ni_（3. 50）Co_（0. 15） alloys at the temperatures of 900,950 and 1 000 ℃ is characterized by four stages,i. e.,initial slight shrinkage,expansion,abrupt shrinkage and slight expansion. The maximum shrinkage displacement increases with increasing sintering temperature. All of the alloys consist of（ La,Mg）_2（ Ni,Co）_7 phase; additionally,temperatures of 900 and 950 ℃ are beneficial to the formation of（ La,Mg）（ Ni,Co）_3 phase,whereas the LaNi_5 phase is easy to form in the alloy synthesized by SPS at 1 000 ℃. The electrochemical measurements indicate an evident change of the electrochemical performance of the alloys associated with increasing the sintering temperature. The discharge capacity of the alloys first increases and then decreases as sintering temperature rises,whereas their cycle stability clearly grows all the time.Furthermore,the charging-discharging potential difference and discharging efficiency both demonstrate that the electrochemical properties of the alloy electrodes first augment and then decline with increasing sintering temperature.

关 键 词：spark plasma sintering La-Mg-Ni system microstructure electrochemical property 

分 类 号：TG146.45[一般工业技术—材料科学与工程]