摘要
鉭(Ta)具有優異生物相容性、耐蝕性、機械性質以及無毒性，在金屬醫材中已成為最被重視的新材料之一，但全Ta植體價格昂貴，不易普及。本研究選用Ti6Al4V鈦合金為基材，Ta粉為披覆材，以降低成本，並搭配商業化且品質優異之真空電漿熔射法(VPS)作為披覆製程。實驗中以電漿熔射功率為變動參數；電漿氣體與流率、送粉氣體與流率、熔射距離及真空腔體壓力等為固定參數，探討熔射功率的不同對鉭金屬塗層形貌與結合特性之影響。研究結果顯示，各試件塗層與基材間皆可達到良好的接合，塗層呈現具有助於植體與人體骨組織接合之粗糙及孔隙的表面，塗層組織並隨熔射功率的提升而更為緻密，有助於防止基材有害離子的釋出，塗層截面硬度介於167 ± 11~ 229 ± 8 HV，較基材(292 ± 10 HV)為低，可降低植體與人體骨組織間之應力遮蔽效應。
關鍵詞：真空電漿熔射、熔射功率、鉭金屬、Ti6Al4V鈦合金
Abstract
Tantalum (Ta), a non-toxic metal, has become one of the most important medical materials, because of its excellent biocompatibility, corrosion resistance, and mechanical properties. In this study, vacuum plasma spray (VPS) was used for the spraying process, and Ti6Al4V alloy and Ta powder were respectively utilized as substrate and coating material. Different levels of power were set for the coating parameters with the same conditions of plasma gas and flow rate, carried gas and flow rate, and spraying stand-off distance and chamber pressure. The influence of Ta coating between morphology and chemical composition was investigated with different power levels. The results showed that all specimens have performed a good bonding between the substrate and coating. The coatings all display a rough surface with pores, which is beneficial to the joining of human bone tissue and the implant. With an increase of power, the coating becomes denser to prevent the release of harmful ions. The hardness along the coating section is between 167 ± 11~ 229 ± 8 HV, and is relatively lower than the substrate (292 ± 10 HV). As a result, it can reduce the stress shielding effect between the implant and the human bone tissue.
Keywords : Vacuum Plasma Spray, Spraying Power, Tantalum, Ti6Al4V Alloy