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为了消除激光熔覆过程中基材与生物陶瓷涂层之间的热应力,提高涂层与基材的结合强度,采用宽带激光熔覆技术,在Ti-6Al-4V合金表面制备含HA+β-TCP的生物陶瓷梯度涂层(HA为羟基磷灰石)。利用OM、SEM和XRD对涂层形貌、相组成进行了研究,并通过体外模拟体液浸泡实验考察了涂层的生物活性。结果表明:生物陶瓷梯度涂层分为基材、合金化层以及生物陶瓷层3个层次,且各梯度层的结合界面均为良好的化学冶金结合。稀土氧化物La2O3在激光熔覆生物陶瓷过程中具有诱导合成HA+β-TCP的作用,生物陶瓷涂层的生物活性与不同La2O3含量诱导合成HA+β-TCP的数量密切相关。当La2O3含量为0.6 wt.%时,合成HA+β-TCP的数量最多。当La2O3的添加量为0.6 wt.%时,涂层表面形成的类骨磷灰石数量最多;且经14天浸泡后的涂层明显比7天形成的类骨磷灰石数量多。
In order to eliminate the thermal stress between the substrate and the bioceramic coating during the laser cladding and improve the bonding strength between the coating and the substrate, a broadband laser cladding technique was used to prepare the surface of the Ti-6Al-4V alloy containing HA + β -TCP bioceramic gradient coating (HA is hydroxyapatite). The morphology and phase composition of the coating were investigated by OM, SEM and XRD. The biological activity of the coating was investigated by in vitro simulated somatic immersion test. The results show that the bio-ceramic gradient coating is divided into three layers: substrate, alloyed layer and bio-ceramic layer, and the interface of each gradient layer is a good chemical metallurgical bond. The rare earth oxide La2O3 has the effect of inducing the synthesis of HA + β-TCP during laser cladding of the bio-ceramic. The biological activity of the bio-ceramic coating is closely related to the amount of HA + β-TCP induced by different La2O3 contents. When La2O3 content was 0.6 wt.%, The amount of HA + β-TCP was the most. When the dosage of La2O3 is 0.6 wt.%, The amount of osteoid apatite formed on the surface of the coating is the largest; and after 14 days of soaking, the number of the coating is obviously more than that of the bone-like apatite formed on the 7th day.