饰用银合金珠粒熔铸试验

Melting and Casting Testof Silver Bead for Jewelry

采用纯银及其合金为试验材料,以石墨板为基底在大气下将银材料熔铸成珠,并借助差热分析仪、超景深显微镜、X射线能谱仪等手段对银珠品质进行评价。结果表明,采用石墨基底在大气下熔铸时,纯银可以获得良好的珠化效果,而Ag-Cu合金表面的氧化产物会明显影响液滴的珠化。在同等熔铸工艺条件下,随着Cu含量升高或者珠粒粒径增加,Ag-Cu合金液滴聚团圆珠化的难度加大。采用细线材下料时,抗变色925银合金液滴比斯特林银聚团珠化更困难。采用硼砂包埋熔铸,有利于形成圆整度较好、表面较干净的珠粒。

Taking pure silver and its alloy as testing materials and graphite as matrix,the silver material was melted and cast into beads under atmosphere,which was evaluated by means of differential thermal analyzer,ultra depth of field microscope and X-ray photoelectron spectroscopy.The results indicate that pure silver can obtain desirable beading effect when graphite substrate is cast in the atmosphere,while the oxidation products on the surface of Ag-Cu alloy can obviously affect the bead formation of droplets.Under the same melting and casting process conditions,the difficulty of spheroidization for Ag-Cu alloy droplet is raised with the increase of Cu content or bead size.When thin wire is adopted for blanking,the anti-tarnishing 925 silver alloy droplets are more difficult to bead than Stirling silver.Borax embedding casting is beneficial to the formation of beads with better roundness and cleaner surface.