“5 G金”首饰成分、硬度和工艺探析

Research on composition, hardness and process of "5 G gold" jewelry

摘要: 采用火试金法、ICP差减法、显微硬度计对“5 G金”首饰的纯度和硬度进行了检测。结果表明：市面上“5 G金”首饰的纯度满足GB11887—2012《首饰贵金属纯度的规定及命名方法》要求；所测“5 G金”首饰硬度最小值为29.2 HV，最大值为120.7 HV，多数样品硬度值为50~80 HV。“5 G金”首饰主要通过微合金化、冷变形、表面电铸等方式提高硬度，涉及固溶强化、沉淀强化、变形强化、细晶强化等机制。

Abstract: The fineness and hardness of "5 G gold" jewelry were tested by fire assay， ICP difference method， and microscopic hardness tester. The results show that the fineness of "5 G gold" jewelry on the market meets the requirements of GB11887—2012 Jewelry—Fineness of Precious Metal Alloys and Designation； the minimum hardness of the tested "5 G gold" jewelry is 29.2 HV， and the maximum is 120.7 HV. The hardness value of most samples is in the range of 50-80 HV. The hardness of "5 G gold" jewelry is mainly improved through micro alloying， cold deformation， surface electroforming， and other methods， involving solid solution strengthening， precipitation strengthening， deformation strengthening， and fine-grain strengthening mechanisms.