La2O3 addition for improving the brazed joints of WC-Co/1Cr13
La2O3 addition for improving the brazed joints of WC-Co/1Cr13
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DOI：
10.1016/j.jmatprotec.2018.11.045
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发表时间：
2019-05
影响因子：
6.3
通讯作者：
Y. Xiao;P. Liu;Z. Wang;Y. Wang;K. Feng;L. Chen
中科院分区：
文献类型：
--
作者：
Y. Xiao;P. Liu;Z. Wang;Y. Wang;K. Feng;L. Chen
采用实验和计算热力学相结合的方法，研究了氧化镧（La 2 O3）作为中间层对碳化钨/钴（WC-Co）硬质合金与1Cr 13不锈钢钎焊接头组织和力学性能的影响。实验发现，由于La 2 O3的加入，在有害的η相（Co 3 W3C）附近出现了碳化物固溶体相（CSSP）。观察到这样的CSSP抑制η相的形成。通过比较奥氏体相、CSSP相和η相的吉布斯自由能，从理论上解释了其缓蚀机理。La 2 O3的加入有效地促进了奥氏体相的异质形核，细化了晶粒，使奥氏体相分布均匀。添加La 2 O3的钎焊接头的剪切强度（≥ 340 MPa）优于未添加La 2 O3的钎焊接头。
The effects of lanthanum oxide (La2O3) as an interlayer component on microstructures and mechanical properties of brazed joints of tungsten carbide/cobalt (WC-Co) cemented carbides and the 1Cr13 stainless steel are investigated by an integrated experimental and computational thermodynamics approach. A carbide solid solution phase (CSSP) is experimentally identified adjacent to the detrimental η phase (Co3W3C) due to the addition of La2O3. Such a CSSP is observed to suppress the formation of η phase. The underlying inhibition mechanism is then explained thermodynamically by comparing the Gibbs free energy of the austenite, CSSP and η phases. The added La2O3is also found to effectively promote the heterogeneous nucleation of the austenite phase, which results in the grain refinement and the uniform distribution of the austenite phase. The shear strength (∼340 MPa) of the brazed joints with La2O3addition outperforms the counterparts without La2O3.