Fracture toughness, diametrical strength, and fractography of amalgam and of amalgam to amalgam bonds.
Fracture toughness, diametrical strength, and fractography of amalgam and of amalgam to amalgam bonds.
复制标题
汞齐和汞齐与汞齐键的断裂韧性、直径强度和断口。
DOI：
10.1016/0109-5641(93)90106-z
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Mueller,HJ
中科院分区：
文献类型：
--
作者：
Bapna,MS;Mueller,HJ
人字形缺口断裂韧性，径向抗拉强度和断口分析进行了评价散装汞合金和新的和1天的旧汞合金之间形成的债券相同类型。制备了三种类型的粘结试样：1）用600粒度的纸机械粗糙化1天的汞合金; 2）使用新的富汞汞合金; 3）使用粘结树脂，4-Meta或磷酸酯单体。两个商业分散相结合的汞合金，其中之一含有钯的所有键合技术，得到类似的值键合性能，但是，含钯的汞合金的体积断裂韧性显着小于无钯的汞合金。这一结果表明，汞合金与汞合金的粘结，至少对于这两种汞合金而言，是一种与表面有关的现象，因此，将粘结性能报告为本体性能百分比的传统方法失去了意义。短棒几何形状更能代表界面粘结性能，因为这些样品在界面粘结内断裂，而径向强度样品通常在远离界面处轻微断裂。粘结树脂的使用并没有改善粘结断裂韧性的任何汞合金，而径向强度改善的汞合金之一。与所有其他技术相比，使用富汞汞合金显著提高了一种汞合金的断裂韧性，同时证明与第二种汞合金的600粒度制备相似。断口分析表明，断裂沿着粘结界面通过铜锡相（围绕分散相或分布在基体中）和银汞相（通常为沿晶断裂）扩展。检测到树脂残留物，已因断裂而松动或仍粘附在隔离区域。散装汞合金之间的断口分析的区别可以解释显着差异检测到的断裂韧性。
Chevron-notch fracture toughness, diametrical tensile strength and fractography were evaluated for bulk amalgams and for bonds formed between new and 1-day-old-amalgams of the same type. Three types of bonded specimens were prepared: 1) by mechanically roughening the 1-day-old amalgam with 600-grit paper; 2) using a new mercury-rich amalgam; and 3) using a bonding resin, either 4-META or a phosphate ester monomer. Similar values bond properties were obtained with all bonding techniques for two commercial dispersed-phase bonded amalgams, one of which contained palladium; however, bulk fracture toughness of the palladium-containing amalgam was significantly less than for the palladium-free amalgam. This result reveals that the bonding of amalgam to amalgam, at least for these two amalgams, is a surface-related phenomenon, and thus, the traditional reporting of bonding properties as a percentage of bulk properties loses meaning. Short-rod geometry was more representative of the interfacial bond properties since these samples fractured within the interfacial bonds, while diametrical strength samples often fractured slightly away from the interface. The use of bonding resins did not improve bond fracture toughness for either amalgam, while the diametrical strength improved for one of the amalgams. The use of mercury-rich amalgam significantly improved the fracture toughness over all other techniques for one amalgam, while proving to be similar to a 600-grit preparation for the second amalgam. Fractographic analysis revealed the propagation of the fracture along the bonded interface to be through the copper-tin phase, either surrounding the dispersed phase or distributed in the matrix, and through the silver-mercury phase, often by intergranular fracture. Remains of resin were detected, having been broken loose by fracture or still adhering in isolated regions. Distinctions in the fractography between the bulk amalgams may explain the significant differences detected in their fracture toughnesses.