Mazeau G, Czernuszka J T
La Formation d'Ingenieurs de l'Université Paris-Sud-Orsay, Plateau du Mallon, Bat. 620, 91140 Orsay, France.
Biomed Mater Eng. 2001;11(4):283-92.
Hydroxyapatite has been rubbed against ultra-high-molecular-weight-polyethylene (UHMWPE) under calcium-containg aqueous solutions. Further, hardness tests were carried out in air and in calcium-containing solutions whose pH ranged from pH 5 to pH 9. Hardness was found to vary with pH with a peak at around pH 7, i.e. - a chemomechanical effect was observed. Wear tests consisted in sliding hydroxyapatite samples against a UHMWPE disk for eight hours when lubricated by the same solutions as those used for the hardness tests. Volume loss, pH and calcium concentration were measured for up to 8 hours of sliding. Linking wear tests results with hardness results and supersaturation levels, it was concluded that two wear mechanisms occurred. A chemical mechanism depending on supersaturation occurred at the early stages of sliding. The wear rate was essentially independent of hardness during this stage. After a few hours, depending on the supersaturation of the lubricant, the chemical mechanism turned into a chemomechanical mechanism dependant on hardness.
在含钙水溶液中，羟基磷灰石与超高分子量聚乙烯（UHMWPE）相互摩擦。此外，在空气和pH值范围为5至9的含钙溶液中进行了硬度测试。发现硬度随pH值变化，在pH值约为7时出现峰值，即观察到了化学机械效应。磨损试验包括在与硬度测试相同的溶液润滑下，让羟基磷灰石样品与UHMWPE圆盘滑动摩擦八小时。在长达8小时的滑动过程中测量体积损失、pH值和钙浓度。将磨损试验结果与硬度结果及过饱和度水平联系起来，得出发生了两种磨损机制的结论。在滑动初期，一种取决于过饱和度的化学机制发生作用。在此阶段，磨损率基本与硬度无关。几小时后，根据润滑剂的过饱和度，化学机制转变为取决于硬度的化学机械机制。
