Microstructure and Mechanical Properties of an in situ Synthesized TiB and TiC Reinforced Titanium Matrix Composite Coating
Microstructure and Mechanical Properties of an in situ Synthesized TiB and TiC Reinforced Titanium Matrix Composite Coating
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原位合成 TiB 和 TiC 增强钛基复合涂层的微观结构和力学性能
DOI：
10.1007/s11595-012-0397-3
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发表时间：
2012-02-01
影响因子：
1.6
通讯作者：
Li Manping
中科院分区：
文献类型：
--
作者：
Li Jun;Yu Zhishui;Li Manping
采用激光熔覆技术在Ti6 A14 V基体上制备了原位合成TiB和TiC颗粒增强的钛基复合涂层。研究了其显微组织和力学性能。涂层主要由α-Ti胞状枝晶和共晶组成，共晶中均匀嵌有大量棒状/针状TiB和少量等轴状TiC颗粒。显微组织演化可分为4个阶段：初生β Ti相的析出和长大、二元共晶β Ti +TiB的形成、三元共晶β Ti +TiB+TiC的形成和β Ti向α Ti的固态转变。涂层的显微硬度从表面（HV 0.2 876）到底部（HV 0.2 660）呈梯度变化，与基体相比有显著提高。涂层的断裂韧性从表面（6.3MPa·m（1/2））到界面（11.9MPa·m（1/2））呈梯度变化。涂层的耐磨性明显优于Ti 6 A14 V涂层的耐磨性（上级）。
A titanium-based composite coating reinforced by in situ synthesized TiB and TiC particles was fabricated on Ti6A14V by laser cladding. The microstructure and mechanical properties were investigated. The coating was mainly composed of alpha-Ti cellular dendrites and an eutectic in which a large number of rod/needle-shaped TiB and a few equiaxial TiC particles were homogeneously embedded. The microstructural evolution could be divided into four stages: precipitation and growth of primary beta-Ti phase, formation of the binary eutectic beta-Ti+TiB, formation of the ternary eutectic beta-Ti+TiB+TiC, and solid transformation from beta-Ti to alpha-Ti. Microhardness of the coating showed a gradient variation from the surface (about HV0.2 876) to the bottom (about HV0.2 660) and was prominently improved in comparison with that of the substrate. Fracture toughness of the coating also exhibited a gradient variation from the surface (6.3 MPa.m(1/2)) to the interface (11.9 MPa.m(1/2)). Wear resistance of the coating was significantly superior to that of Ti6A14V.