Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray (HVOF) from hydroxyapatite (HAp) and bioactive glasses (BG) have the potential to be employed on temporary implants due to the ability of both HAp and BG to dissolve and promote osseointegration, considering that both phases have different reaction and dissolution rates under in-vitro conditions. In the present work, 75% wt. HAp - 25% wt. S53P4 bioactive glass powders were HVOF-sprayed to obtain HAp/S53P4 BG composite coatings on a bioresorbable AZ31 alloy. The study is focused on exploring the effect of the stand-off distance and fuel/oxygen ratio variation as HVOF parameters to obtain stable structural coatings and to establish their effect on the phases and microstructure produced in those coatings. Different characterization techniques, such as scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy, were employed to characterize relevant structural and microstructural properties of the composite coatings. The results showed that thermal gradients during coating deposition must be managed to avoid delamination due to the high temperature achieved (max 550 °C) and the differences in coefficients of thermal expansion. It was also found that both spraying distance and oxygen/fuel ratio allowed to keep the hydroxyapatite as the main phase in the coatings. In addition, in-vitro electrochemical studies were performed on the obtained HAp/S53P4 BG composite coatings and compared against the uncoated AZ31 alloy. The results showed a significant decrease in hydrogen evolution (at least 98%) when the bioactive coating was applied on the Mg alloy during evaluation in simulated body fluid (SBF).

由羟基磷灰石 (HAp) 和生物活性玻璃 (BG) 通过高速氧燃料喷涂 (HVOF) 生产的生物活性热喷涂涂层具有用于临时植入物的潜力，因为 HAp 和 BG 都具有溶解和促进骨整合的能力，考虑到两个相在体外条件下具有不同的反应和溶解速率。在目前的工作中，75% wt。HAp - 25% 重量 采用 HVOF 喷涂 S53P4 生物活性玻璃粉末，在可生物吸收的 AZ31 合金上获得 HAp/S53P4 BG 复合涂层。该研究的重点是探索间隔距离和燃料/氧气比变化作为 HVOF 参数的影响，以获得稳定的结构涂层，并确定它们对这些涂层中产生的相和微观结构的影响。采用扫描电子显微镜、X射线衍射和傅里叶变换红外光谱等不同的表征技术来表征复合涂层的相关结构和微观结构特性。结果表明，必须控制涂层沉积过程中的热梯度，以避免由于达到的高温（最高 550 °C）和热膨胀系数差异而导致分层。还发现喷涂距离和氧/燃料比都可以使羟基磷灰石保持为涂层中的主要相。此外，对获得的 HAp/S53P4 BG 复合涂层进行了体外电化学研究，并与未涂层的 AZ31 合金进行了比较。结果表明，在模拟体液 (SBF) 中进行评估时，在镁合金上涂覆生物活性涂层后，析氢量显着减少（至少 98%）。