Design and production of yellow-green coloured precious metal alloys'

From past to present, precious metals have an important place in mankind's life. Especially gold, with the brilliant colour and high mechanical properties, is always a symbol of power and wealth. Down the ages, gold has been used as jewelry and decorative items. Gold is the most important raw material for the jewellery. Jewellery has an important place in our country. Gold is the one of the primary inputs of this sector. Jewellery has a large production volume and a lot of import master alloys are being used for casting. The main goal of this study is to product an alternative domestic master alloy. In this study, properties of the domestic products are compared with the reference master alloy products' properties. Investment casting is one of the most popular techniques for the casting of gold alloys. This technique is also known as the lost wax casting process. In this study, lost wax casting is used for the casting process. There is lots of information for the steps of this technique. This is a research study for general properties of gold, investment casting process, gold production by this technique and colour of gold alloys, hardness and tensile tests, elongation, DTA and grain size of gold alloys. Alloy design was changed many times during this study and effects of these changes on the alloy's properties were analyzed. All the tests were performed to the both samples which are made by new designed alloy and reference alloy. The results of the tests were compared. Key words: Gold, gold alloys, mechanical properties, colour, investment casting, hardness, tensile test, DTA, grain size