Control of Mechanical Properties of Three-Dimensional Ti-6Al-4V Products Fabricated by Electron Beam Melting with Unidirectional Elongated Pores
Control of Mechanical Properties of Three-Dimensional Ti-6Al-4V Products Fabricated by Electron Beam Melting with Unidirectional Elongated Pores
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DOI：
10.1007/s11661-014-2396-9
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发表时间：
2014-09-01
影响因子：
2.8
通讯作者：
Nakano, Takayoshi
中科院分区：
文献类型：
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作者：
Ikeo, Naoko;Ishimoto, Takuya;Nakano, Takayoshi
在电子束熔化制备的Ti-6Al-4V产品中加入了定向、单向、细长的孔隙，以控制产品的机械性能，使其适合生物医学应用。当电子束的扫描间距大于电子束的直径时，可以成功地产生单向孔。通过改变电子束的扫描间距，可以改变单向孔的大小。结果表明，由于多孔材料强度与孔隙度关系方程中的应力集中系数为1，具有单向孔隙的产品的杨氏模量和屈服应力随孔隙度的增加而线性减小。此外，当扫描间距为1 mm或更大时，杨氏模量较低（< 35 GPa），这些值接近人类皮质骨的典型杨氏模量。这表明，这些多孔材料可用于制造定制的骨植入物，这些骨植入物具有所需的机械性能，并抑制了通常使用钛合金植入物时注意到的骨的应力屏蔽。
Aligned, unidirectional, elongated pores were incorporated in Ti-6Al-4V products fabricated by electron beam melting in order to control the mechanical properties of the products such that they became suitable for biomedical applications. Unidirectional pores were successfully produced when the scan spacing of the electron beam was greater than the diameter of the beam. By changing the scan spacing of the electron beam, the size of the unidirectional pores could be varied. As a result, both the Young's moduli and the yield stresses of the products with unidirectional pores decreased linearly with an increase in their porosity, owing to the stress concentration coefficient being 1 in the equation representing the relation between strength and porosity for porous materials. Further, low (< 35 GPa) Young's moduli were obtained when the scan spacing was 1 mm or higher, with these values being were close to the typical Young's modulus of human cortical bone. This suggested that these porous materials could be used to fabricate customized bone implants that exhibited desired mechanical properties and suppressed the stress shielding of bone that is normally noticed when implants made of Ti alloys are used.