Sarkar N K, Eyer C S
J Oral Rehabil. 1987 Jan;14(1):27-33. doi: 10.1111/j.1365-2842.1987.tb00690.x.
A previous study has shown that the addition of small amounts of tin to gamma 1 leads to the formation of a SnHg intergranular precipitate. The purpose of this study was to determine the effect of this precipitate on the creep of gamma 1. Two groups of samples were investigated. Group I included a series of gamma 1 samples with 0, 1, 2, and 3 wt% Sn fabricated by a sintering technique at 55 degrees C and 125 mN/m2 for 72 h. Group II contained the same samples as in Group I that were further annealed at 60 degrees C for 2000 h. Annealing was carried out to allow gamma 1 grain growth and equilibrium distribution of Sn at grain boundaries. Creep tests were conducted according to the American Dental Association Specification 1. The microstructures of all samples were characterized by scanning electron microscopy. The creep of gamma 1 was found to be controlled by the intergranular precipitate when the Sn concentration was above 1%. For a specific concentration of Sn, i.e. the intergranular precipitate, creep was dependent on the distribution of Sn and not on the gamma 1 grain size. The more nearly continuous precipitates found in annealed samples favoured higher creep.
先前的一项研究表明，向γ1中添加少量锡会导致形成SnHg晶界沉淀物。本研究的目的是确定这种沉淀物对γ1蠕变的影响。研究了两组样品。第一组包括一系列通过在55℃和125mN/m2的条件下烧结72小时制备的含0、1、2和3wt%锡的γ1样品。第二组包含与第一组相同的样品，这些样品在60℃下进一步退火2000小时。进行退火是为了使γ1晶粒生长并使锡在晶界处达到平衡分布。根据美国牙科协会规范1进行蠕变试验。所有样品的微观结构通过扫描电子显微镜进行表征。当锡浓度高于1%时，发现γ1的蠕变受晶界沉淀物控制。对于特定浓度的锡，即晶界沉淀物，蠕变取决于锡的分布而不是γ1的晶粒尺寸。在退火样品中发现的更接近连续的沉淀物有利于更高的蠕变。
