TiB2基陶瓷-42CrMo合金钢层状复合材料界面结构与力学性能

Interfacial structure and mechanical properties of laminated composites of TiB2 based ceramic-42CrMo alloy steel

  • 摘要: 采用自蔓延高温合成离心熔铸工艺可以快速制备出TiB2基陶瓷-42CrMo合金钢层状复合材料,并在层间界面上形成TiB2基陶瓷/Fe-Ni合金相三维网络跨尺度连续梯度复合结构,使层状复合材料分为陶瓷基体、中间过渡区与合金钢基底3层结构。通过材料力学性能测试并结合FESEM、HRTEM观察,得出正是由于层间界面上原位生成TiB2基陶瓷/Fe-Ni合金的三维网络跨尺度连续梯度复合结构,使复合材料不仅具有高的弯曲强度与断裂韧性,而且又使之在三点弯曲测试时呈现出明显的“假塑性”力学行为特征。同时,陶瓷基体附近界面上TiB2基陶瓷/Fe-Ni基合金复合结构裂纹互锁效应与中间过渡区上TiB2微纳米/纳米晶沉淀强化机制的协同作用又使TiB2基陶瓷-42CrMo合金钢层状复合材料具有高的层间界面剪切强度。

     

    Abstract: The laminated composites of TiB2 based ceramic-42CrMo alloy steel were rapidly prepared by self-propagating high-temperature synthesis centrifugal-casting process, and the span-scale continuously-graded composite structures of three dimensional-network TiB2 matrix ceramic/Fe-Ni alloy developed on the interface between the layers, leading to the laminated composite with 3-layer structure consisting of ceramic matrix, the intermediate and alloy steel matrix. Combining mechanical properties test with FESEM and HETEM examination, it is considered that the in-situ achievement of the continuously-graded composite structure of three dimensional-network span-scale TiB2 matrix ceramic/Fe-Ni alloy in interlaminar interface not only presents the laminated composite with high flexural strength and high fracture toughness, but also presents the composite with the mechanic behavior of bogus plasticity when the three point bending test conducts. Meanwhile, the cooperative action of crack interlocking by TiB2 matrix ceramic/Fe-Ni based alloy composite structure nearby the ceramic matrix with precipitation strengthening by micro-nanometer or nanometer TiB2 platelets in the intermediate also presents the laminated composite of TiB2 based ceramic-42CrMo alloy steel with high interlaminar shear strength.

     

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