稀土对激光涂覆生物陶瓷涂层组织的影响

Effect of Y 2 O 3 on the Microstructure of Laser Clad Bioceramic Coatings

通过在钛合金表面上预涂敷一定比例的ＣａＨＰＯ４·２Ｈ２Ｏ－ＣａＣＯ３混合粉末及相应的过渡层并进行激光熔覆处理，获得了以ＴＣ４为基的含羟基磷灰石（ＨＡ）的生物陶瓷涂层复合材料。同时研究了稀土元素的加入对于生物陶瓷涂层组织的影响。结果表明，Ｙ２Ｏ３不仅对涂层组织有细化作用，而且对激光合成ＨＡ有催化作用并能使ＨＡ相结构保持稳定。

Since the 1970s, some scholars have tried to coat bioceramics on to metal substrates by plasma spray, CVD and PVD etc However, using these processes, the uniformity of the bioceramic coating has been poor and the bonding strength has been weak resulting in a coating that drops off in clinical practice Therefore a hydroxyapatite(HA) composite bioceramic layer was made by coating a mixture of powders (CaHPO 4 ·2H 2 O)+CaCO 3 +Y 2 O 3 ) on to TC4 and laser cladding The influence of Y 2 O 3 in the coating layer on its microstructure has been studied The results show that: (1) The main factors, which facilitate the forming of the bioceramic coating, are the low power and high speed of the laser In this experiment the laser process parameters have been optimized in terms of power (1273～1527)W/cm 2 and scanning speed (550～650)mm/min A composite bioceramic coating including HA, β-TCP etc can be formed (2) The addition of Y 2 O 3 in coating to the layer refine the grain size of the coating The results is higher bonding strength and fracture toughness, and improvement in the biocompatibility of HA, β-TCP etc