基于金银合粒组织结构和性能的金量测定影响探讨

Discussion of the effect on gold content detection based on structure and properties of gold-silver alloys

摘要: 利用Ｘ射线衍射仪、差示扫描量热仪、电化学工作站、显微硬度计对火试金法中金银合粒的组织结构、耐腐蚀性、力学性能进行了研究。结果表明：银、金质量比分别为2.1，2.3和2.5时金银合粒的分子式为Ag79Au21、Ag81Au19和Ag82Au18，均为银基固溶体，其熔化开始温度和凝固结束温度相近，耐腐蚀性和力学性能相似。采用火试金法测定金合金首饰中金量时，银、金质量比为2.1～2.5对测定结果没有影响。

Abstract: The structure,corrosion resistance and mechanical properties of gold-silver alloys were studied by X-ray diffractometer,differential scanning calorimetry,electrochemical workstation and microhardness tester.The results show that the Ag79Au21,Ag81Au19 and Ag82Au18 alloys are all silver-based solid solution,corresponding to the mass ratio of silver to gold 2.1,2.3,2.5.The initial melting temperature and the final solidification temperature of the three alloys are similar.In addition,the three alloys display similar corrosion resistance and mechanical properties.Therefore,the silver-gold mass ratio(between 2.1 and 2.5) has no effect on the test results when the gold jewelry is tested by fire assay.