State Key Lab of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001, China.
Micron. 2013 Feb;45:92-6. doi: 10.1016/j.micron.2012.11.001. Epub 2012 Nov 12.
In the present work, Ti fibre reinforced Al matrix composites (Ti(f)/Al) were fabricated by pressure infiltration method. In order to suppress the severe Ti-Al reaction and reduce the formation of brittle TiAl(3) phase, a TiN layer was coated on Ti fibres by an arc ion plating method before composite preparation. A thin TiN layer was coated on the Ti fibre surface, and the maximum and minimum thickness values of layer were about 3.5 and 1μm, respectively. Prefer orientation of TiN on (111) and (200) was found by XRD analysis. A thin and uniform TiAl(3) layer was observed in Ti(f)/Al composite. However, after coated with TiN layer, no significant reaction layer was found in (Ti(f)+TiN)/Al composite. Segregation of Mg element was found in Ti(f)/Al composite, and the presence of TiN layer showed little effect on this behaviour. Due to the large CTE difference between Ti fibre and Al matrix, high density dislocations were observed in the Al matrix. Meanwhile, fine dispersed Mg(2)Al(3) phases were also found in Al matrix. Ti fibre is mainly composed of α- and β-Ti. Small discontinuous needle-like TiAl(3) phases were detected at TiN/Al interface, which implies that the presence of TiN layer between the Ti fibre and Al matrix could effectively hinder the formation of TiAl(3) phases.
在本工作中，采用压力浸渗法制备了 Ti 纤维增强 Al 基复合材料（Ti(f)/Al）。为了抑制严重的 Ti-Al 反应并减少脆性 TiAl(3)相的形成，在复合体制备前，采用电弧离子镀法在 Ti 纤维表面涂覆了一层 TiN 层。Ti 纤维表面涂覆了一层很薄的 TiN 层，其最大和最小厚度值分别约为 3.5μm 和 1μm。通过 XRD 分析发现 TiN 具有（111）和（200）的择优取向。在 Ti(f)/Al 复合材料中观察到薄而均匀的 TiAl(3)层。然而，在涂覆 TiN 层后，（Ti(f)+TiN)/Al 复合材料中没有发现明显的反应层。在 Ti(f)/Al 复合材料中发现了 Mg 元素的偏析，TiN 层的存在对这种行为几乎没有影响。由于 Ti 纤维和 Al 基体之间的 CTE 差异较大，在 Al 基体中观察到高密度位错。同时，在 Al 基体中还发现了细小弥散的 Mg(2)Al(3)相。Ti 纤维主要由 α-和 β-Ti 组成。在 TiN/Al 界面处检测到小的不连续针状 TiAl(3)相，这表明 Ti 纤维和 Al 基体之间存在 TiN 层可以有效地阻止 TiAl(3)相的形成。
