Okabe T, Mitchell R J, Butts M B, Galloway S S, Twiggs W S
J Biomed Mater Res. 1985 Jul-Aug;19(6):727-46. doi: 10.1002/jbm.820190611.
Low-copper amalgams aged at 37 degrees C, 50 degrees C, 60 degrees C, 70 degrees C, and 80 degrees C for periods of 7 and 30 days were examined using a scanning electron microscope and an x-ray diffractometer. Gamma-one Ag-Hg grain size and gamma 2 Sn-Hg volume fraction, and surface area were determined by quantitative metallography. At 60 degrees C and below, gamma 1 was the predominant matrix phase. Little beta 1 Ag-Hg was found. In this temperature range, both gamma 1 grain size and ADA creep were found to obey an Arrhenius law. A linear relationship was found between the log of the mean ADA creep and the mean gamma 1 grain size. Above 60 degrees C, the gamma 1 phases and the majority of the gamma Ag-Sn particles disappeared. In their place, beta 1 appeared. Gamma-two volume fraction increased during aging at temperatures over 60 degrees C, but a coarsening of gamma 2, reflected in a decrease in gamma 2 surface area per unit volume, also took place. Aging for 30 days or less resulted in decreases in ADA creep. At 60 degrees C and below, the decrease was caused by increases in gamma 1 grain size. Above 60 degrees C, the decrease in ADA creep was caused by several factors, one of which was the appearance of large beta 1 grains.
使用扫描电子显微镜和X射线衍射仪对在37摄氏度、50摄氏度、60摄氏度、70摄氏度和80摄氏度下分别老化7天和30天的低铜汞合金进行了检查。通过定量金相分析确定了γ1银汞晶粒尺寸、γ2锡汞体积分数和表面积。在60摄氏度及以下，γ1是主要的基体相。几乎未发现β1银汞。在此温度范围内，γ1晶粒尺寸和ADA蠕变均符合阿累尼乌斯定律。发现平均ADA蠕变的对数与平均γ1晶粒尺寸之间存在线性关系。在60摄氏度以上，γ1相和大部分γ银锡颗粒消失。取而代之的是β1出现。在60摄氏度以上的温度下老化时，γ2体积分数增加，但γ2也发生了粗化，表现为单位体积γ2表面积的减小。老化30天或更短时间会导致ADA蠕变降低。在60摄氏度及以下，降低是由γ1晶粒尺寸增加引起的。在60摄氏度以上，ADA蠕变降低是由几个因素导致的，其中之一是出现了大的β1晶粒。
