Processing of an ultrafine-grained titanium by high-pressure torsion: An evaluation of the wear properties with and without a TiN coating
Processing of an ultrafine-grained titanium by high-pressure torsion: An evaluation of the wear properties with and without a TiN coating
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DOI：
10.1016/j.jmbbm.2012.08.018
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发表时间：
2013-01-01
影响因子：
3.9
通讯作者：
Langdon, Terence G.
中科院分区：
文献类型：
--
作者：
Wang, Chuan Ting;Gao, Nong;Langdon, Terence G.
对工业纯钛(Cp)2级钛进行了常温高压扭转(HPT)处理，压力为3.0 Gpa。HPT处理使晶粒尺寸从原始状态的8.6微米减小到130 nm左右的超细颗粒。拉伸测试表明，经HPT处理的钛具有较高的极限抗拉强度(接近940 Mpa)和合理的断裂伸长率(接近23%)。采用物理气相沉积的方法在钛表面沉积了厚度为2.5微米的TiN涂层，并对其进行了HPT处理。划痕试验表明，TiN涂层的临界破坏载荷为22.5N，而粗晶TiN涂层的临界载荷仅为12.7N。用一个简单的复合硬度模型解释了这种差异。磨损试验表明，以超细钛为基材时，TiN涂层的耐磨性得到了提高。结果表明，经HPT处理后再涂覆TiN的CP钛为生物植入提供了一种潜在的重要材料。(C)2012爱思唯尔有限公司。保留所有权利。
A commercial purity (CP) Grade 2 Ti was processed by high-pressure torsion (HPT) using an imposed pressure of 3.0 GPa at room temperature. The HPT processing reduced the grain size from similar to 8.6 mu m in the as-received state to ultra-fine grains (UFG) of similar to 130 nm after HPT. Tensile testing showed the HPT-processed Ti exhibited a good combination of high ultimate tensile strength (similar to 940 MPa) and a reasonable elongation to failure (similar to 23%). Physical vapour deposition was used to deposit TiN coatings, with a thickness of 2.5 mu m, on Ti samples both with and without HPT processing. Scratch tests showed the TiN coating on UFG Ti had a critical failure load of 22.5 N whereas the load was only similar to 12.7 N for the coarse-grained Ti. The difference is explained using a simple composite hardness model. Wear tests demonstrated an improved wear resistance of TiN coating when using UFG Ti as the substrate. The results suggest that CP Ti processed by HPT and subsequently coated with TiN provides a potentially important material for use in bio-implants. (c) 2012 Elsevier Ltd. All rights reserved.