Altering the wetting properties of orthopaedic titanium alloy (Ti-6Al-7Nb) using laser shock peening

JOURNAL OF ALLOYS AND COMPOUNDS

卷:801

Article

Shen, Xiaojun¹  Shukla, Pratik¹  Swanson, Philip¹  An, Zhibin²  Prabhakaran, S.³  Waugh, David¹  Nie, Xiangfan⁴  Mee, Christopher⁵  Nakhodchi, Soheil⁶  Lawrence, Jonathan¹ 

[1] Coventry Univ, Sch Mech Aerosp & Automot Engn, Fac Engn Environm & Comp, Priory St, Coventry CV1 5FB, W Midlands, England

[2] Air Force Engn Univ, Sci & Technol Plasma Dynam Lab, Xian, Shaanxi, Peoples R China

[3] Ctr Crystal Growth, Sch Adv Sci, Vellore Inst Technol, Dept Phys, Vellore 632014, Tamil Nadu, India

[4] East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai 200237, Peoples R China

[5] Coventry Univ, Dept Bimol & Sport Sci, Priory St, Coventry CV1 5FB, W Midlands, England

[6] KN Toosi Univ Technol, Mech Engn Fac, Tehran, Iran

关键词: Ti-6Al-7Nb;    Laser shock peening;    Wettability;    Surface roughness;    Contact angle;    Surface-free energy;    Work of adhesion;   

DOI  :  10.1016/j.jallcom.2019.06.104

来源: Elsevier

【 摘 要 】

This work focuses on exploiting the effects of laser shock peening (LSP) to control the wetting characteristics of bio-material surfaces integrated with surface characteristics such as surface energy, macro and nano-topography. In particular, the effects of laser energy and beam footprint overlap of LSP were explored on Ti-6Al-7Nb alloy, quantified by using the measurement of dynamic contact angle, followed by determination of the surface-free energy and the work of adhesion. Surface modification by LSP was conducted at laser energy of 3 J, 5 J, 7 J, & overlap of 33%, 50%, 67% at 3 mm laser spot diameter. An incremental hole drilling method was employed for near to surface residual stress measurement. The results showed that compressive residual stress of between -42MPa and -516 MPa were formed on the sub-surface of LSPned Ti-6Al-7Nb. The results showed that surface roughness, surface-free energy and work of adhesion were proportional to laser energy, contact angle, however, was found to be inversely proportional to laser energy at consistent overlap. Additionally, surface-free energy and work of adhesion are proportional to overlap, but surface roughness and contact angle have a negative correlation with overlap. The correlation between laser energy and contact angle can be explained by Wenzel's theory while the relationship between overlap and contact angle is described by Cassie-Baxter model. This investigation on effects of LSP on the wetting characteristics not only addresses the required parameters for cell response on LSP modified titanium alloys, but also identifies that a metallic material strengthening process such as laser shock peening can also modify the wettability of a solid metallic surface as well as benefit the mechanical properties of metallic implants. (C) 2019 Elsevier B.V. All rights reserved.

【 授权许可】

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