Introduction of Compressive Residual Stress by Means of Cavitation Peening into a Titanium Alloy Rod Used for Spinal Implants
Introduction of Compressive Residual Stress by Means of Cavitation Peening into a Titanium Alloy Rod Used for Spinal Implants
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DOI：
10.4236/msa.2013.47a2004
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发表时间：
2013-07
期刊：
影响因子：
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通讯作者：
O. Takakuwa;Amrinder S. Gill;G. Ramakrishnan;S. Mannava;V. Vasudevan;H. Soyama
中科院分区：
文献类型：
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作者：
O. Takakuwa;Amrinder S. Gill;G. Ramakrishnan;S. Mannava;V. Vasudevan;H. Soyama
残余压应力的引入是减少脊柱植入物杆与其固定夹具之间微动疲劳和微动磨损的有效方法。本文的目的是证明空化喷丸可以将压缩残余应力引入由医用级钛合金Ti-6Al-4V制成的脊柱植入物棒的表面，该脊柱植入物棒已经过玻璃喷丸处理。为了对直径仅为5.5mm的小直径杆件进行空蚀强化，通过提高环境压力使空蚀区集中。通过X-射线衍射评价所得残余应力的深度分布，然后通过电解抛光去除层。结果表明，空蚀喷丸产生的压缩残余应力更深的杆，即使在近表面的应力值是饱和的，由于初始处理使用玻璃喷丸。随着空蚀处理时间的增加，残余压应力的深度从44 μm不断增加到230 μm。此外，与微观应变密切相关的X射线衍射轮廓的半峰全宽值在空化喷丸的应用之后减小了高达32%。
The introduction of compressive residual stress is an effective way to reduce fretting fatigue and fretting wear between a spinal implant rod and its holding fixture. The objective of this paper is to demonstrate that cavitation peening can introduce compressive residual stress into the surface of a spinal implant rod manufactured from medical grade titanium alloy Ti-6Al-4V, which has already been processed by glass shot peening. In order to apply the cavitation peening for the small rod, whose diameter is only 5.5 mm, the cavitating region was concentrated by increasing the ambient pressure. The depth profiles of the resulting residual stress were evaluated by X-ray diffraction following layer removal by electropolishing. The results show that cavitation peening creates compressive residual stress deeper into the rod, even though the stress value at the near surface is saturated due to initial processing using glass shot peening. The depth of the compressive residual stress continuously increases from 44 μm to 230 μm with an increase in the cavitation peening processing time. In addition, the full width at half maximum value of the X-ray diffraction profile, which is closely related to the micro-strain, decreases by up to 32% following the application of cavitation peening.