Fracture behavior in electrically poled alkaline bismuth- and potassium- based lead-free piezoceramics using Vickers indentation
Fracture behavior in electrically poled alkaline bismuth- and potassium- based lead-free piezoceramics using Vickers indentation
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DOI：
10.1016/j.scriptamat.2020.113647
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发表时间：
2021-03
影响因子：
6
通讯作者：
Xueyao Wang;L. Venkataraman;Chia-Ying Tan;Yingwei Li
中科院分区：
文献类型：
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作者：
Xueyao Wang;L. Venkataraman;Chia-Ying Tan;Yingwei Li
采用维氏压痕技术研究了未极化和电场极化的Ka0.5Na0.5NbO_3(KNN)和Na1/2Bi1/2TiO_3(NBT)系无铅压电陶瓷的断裂行为，并与软质Pb(Zr，Ti)O_3系无铅压电陶瓷进行了比较。在非极化状态下，NBT基压电陶瓷由于其较大的本征断裂韧性，比KNN基压电陶瓷和软PZT压电陶瓷表现出最大的断裂韧性，这与以前的报道一致。在电极化状态下，KNN和NBT基压电陶瓷沿极化方向表现出较大的断裂韧性，而不是垂直于极化方向，其长径比分别为1.2和1.1，明显小于PZT(1.8)。利用裂纹扩展过程中与织构和材料性能有关的残余应变和过程区的变化对结果进行了验证。
The fracture behavior of unpoled and electrically poled Ka0.5Na0.5NbO3(KNN)- and Na1/2Bi1/2TiO3(NBT)- based lead-free piezoceramics were characterized using the Vicker's indentation technique and compared with soft Pb(Zr,Ti)O3piezoceramics. In the unpoled state, NBT-based piezoceramics demonstrate the largest fracture toughness in comparison with KNN-based and soft PZT piezoceramics due to its large intrinsic fracture toughness, which is in accordance with the previous reports. In the electrically poled state, KNN- and NBT- based piezoceramics exhibit large fracture toughness along the poling direction as opposed to perpendicular to the poling direction, with aspect ratios of 1.2 and 1.1, significantly smaller than that for PZT (1.8). The variations of the remanent strain and the process zone, which are related to the texture and the material properties during crack propagation were used to rationalize the results.