Damiano Zito

As part of the fourth industrial revolution, the direct 3D printing of jewelry in precious metal deserves a constant state-of-the-art analysis to see if and how the strengths of this technique should be exploited. Why should jewelry makers decide to use this technique for their production? More precisely, the pragmatists would like another answer: When does this technique add more value compared to traditional investment casting? In recent years, our research path included printing strategies… Visualizza altro

As part of the fourth industrial revolution, the direct 3D printing of jewelry in precious metal deserves a constant state-of-the-art analysis to see if and how the strengths of this technique should be exploited. Why should jewelry makers decide to use this technique for their production? More precisely, the pragmatists would like another answer: When does this technique add more value compared to traditional investment casting? In recent years, our research path included printing strategies, supporting techniques, and examined at different levels of depth the chemical and physical characteristics of the precious metal powders used.
This paper will look back at the technological evolution of direct 3D printing of jewelry with a more practical and operational eye, share our experience and give an honest analysis of its strengths and weaknesses. This detailed examination of the whole work done by Progold will be told through the viewpoint of one who exclaimed, "WOW!" when first introduced to 3D printing and will try to answer when and why it is worthwhile to print a piece of jewelry. Meno dettagli

Direct metal printing is a game changer for creating innovative jewelry. Selective laser melting (SLM™) allows researchers to get creative and think about new materials. This research puts new and different products to the test, exploring fresh horizons for SLM™ utilizing amazing materials for jewelry applications.
Additive manufacturing by selective laser melting provides the opportunity to combine materials with very different properties in otherwise impossible ways. What other… Visualizza altro

Direct metal printing is a game changer for creating innovative jewelry. Selective laser melting (SLM™) allows researchers to get creative and think about new materials. This research puts new and different products to the test, exploring fresh horizons for SLM™ utilizing amazing materials for jewelry applications.
Additive manufacturing by selective laser melting provides the opportunity to combine materials with very different properties in otherwise impossible ways. What other astonishing new possibilities await as we learn about the surprising properties obtained? Meno dettagli

In the world of direct additive manufacturing, Selective Laser Melting (SLM™) of powdered metal is currently one of the most attractive new technologies with potential to replace lost-wax investment casting because it enables the production of items with high geometrical complexity which are light and customizable. In addition, it provides several environmental advantages. In previous testing, improving the quality of items was achieved both by selecting best construction parameters and by… Visualizza altro

In the world of direct additive manufacturing, Selective Laser Melting (SLM™) of powdered metal is currently one of the most attractive new technologies with potential to replace lost-wax investment casting because it enables the production of items with high geometrical complexity which are light and customizable. In addition, it provides several environmental advantages. In previous testing, improving the quality of items was achieved both by selecting best construction parameters and by developing alloys with greater laser absorption. In this work the dimensional accuracy of actual jewelry items is assessed and the possibility of making lighter items while maintaining adequate structural strength is explored.
In addition, the best working parameters for red-gold and platinum alloys were studied. Dimensional accuracy was assessed by building a metal structure and an actual pavé ring. Then the geometrical conformity of the SLM™ ring was compared to the original design. The roughness of the metal section, metal density, metal homogeneity, accuracy of ornamental details and quality as a function of orientation on the build platform will be reported. Meno dettagli

The results previously obtained with gold alloys for selective laser melting - SLM™ - underlined the key role not only of process parameters but also of powder chemical composition for producing quality precious metal jewelry. This paper illustrates the effect of some selected chemical elements to improve laser radiation absorption and to favor the melting of metallic particles.
In addition, the action of the structure and morphology of the supports was examined in order to optimize their… Visualizza altro

The results previously obtained with gold alloys for selective laser melting - SLM™ - underlined the key role not only of process parameters but also of powder chemical composition for producing quality precious metal jewelry. This paper illustrates the effect of some selected chemical elements to improve laser radiation absorption and to favor the melting of metallic particles.
In addition, the action of the structure and morphology of the supports was examined in order to optimize their density and maintain an adequate thermal dissipation of laser energy. Meno dettagli

This paper is a development of the results presented at the 2012 Santa Fe Symposium®. The effect of the most representative variables of the Selective Laser Melting (SLM) technology on the quality of final products is evaluated by means of the design of experiment approach (DOE). The variables taken into account are laser power, scanning speed and thickness of the powder layer. The aim of this paper is to identify the chemicalphysical characteristics of the powder that ensure the best results… Visualizza altro

This paper is a development of the results presented at the 2012 Santa Fe Symposium®. The effect of the most representative variables of the Selective Laser Melting (SLM) technology on the quality of final products is evaluated by means of the design of experiment approach (DOE). The variables taken into account are laser power, scanning speed and thickness of the powder layer. The aim of this paper is to identify the chemicalphysical characteristics of the powder that ensure the best results of the SLM technique.
Analysis of the influence of chemical composition and powder particle size distribution on porosity and roughness of the final items is specifically studied. This work describes the progress obtained with SLM technology in the last year, and evidences the importance of optimising process parameters. All presented results were obtained using precious metal alloys. Meno dettagli

Selective laser melting (SLM) of layered gold powder is a rapid manufacturing (RM) technology capable of turning a CAD model into a jewel without intermediate steps. As with any new technology, giving concrete and tangible form to concepts requires research and development and as Strauss (SFS 2009) points out, issues that can arise with RM jewelry regard powder quality and availability.
This paper focuses on these issues together with laser power, laser scanning speed and the thickness of… Visualizza altro

Selective laser melting (SLM) of layered gold powder is a rapid manufacturing (RM) technology capable of turning a CAD model into a jewel without intermediate steps. As with any new technology, giving concrete and tangible form to concepts requires research and development and as Strauss (SFS 2009) points out, issues that can arise with RM jewelry regard powder quality and availability.
This paper focuses on these issues together with laser power, laser scanning speed and the thickness of powder layer. A design of experiments (DOE) approach was used to characterize the influence of those variables on a 18kt gold powder with reference to physical and chemical attributes, surface roughness, defects, and mechanical properties. A comparison of a series of specimens produced by SLM and lost wax casting will be presented. Meno dettagli

Data about the characterization of 18kt gold alloys were presented by Progold at the 2010 Santa Fe Symposium. In this paper, we are going to discuss the chemical and physical properties of 14kt red, yellow and white gold alloys.
As with 18kt gold alloys, knowing the alloys properties enables us to choose the most suitable composition for each particular production process. Colour is fundamental to the selection of a gold alloy, but how to get the desired color and favourable working… Visualizza altro

Data about the characterization of 18kt gold alloys were presented by Progold at the 2010 Santa Fe Symposium. In this paper, we are going to discuss the chemical and physical properties of 14kt red, yellow and white gold alloys.
As with 18kt gold alloys, knowing the alloys properties enables us to choose the most suitable composition for each particular production process. Colour is fundamental to the selection of a gold alloy, but how to get the desired color and favourable working properties is a question.
In this paper we analyze how small additions of some elements may improve some important characteristics in the production cycle. The goal is to correlate the features of each alloy with its chemical composition so you can choose the optimum 14kt gold alloy for each use.
The methods and tests used to collect data are not presented here as they are the same used with the 18ct gold alloys reported in the Proceedings of the 2010 Santa Fe Symposium. Meno dettagli

Knowing gold alloys characteristics enables to get precious information for selecting the most suitable alloy composition for each particular production process. Obviously, in the case of gold alloys, color plays a fundamental role in the selection of the composition to be used, but in all cases minor additions of some specific elements can contribute to improve some characteristics that are important in the production process. On the basis of these considerations, we decided to determine the… Visualizza altro

Knowing gold alloys characteristics enables to get precious information for selecting the most suitable alloy composition for each particular production process. Obviously, in the case of gold alloys, color plays a fundamental role in the selection of the composition to be used, but in all cases minor additions of some specific elements can contribute to improve some characteristics that are important in the production process. On the basis of these considerations, we decided to determine the chemical and physical properties of several 9, 10, 14 and 18kt gold alloys.
The aim of this work was to correlate the characteristics of each alloy with the chemical composition, to be able to select the gold alloy representing the optimum solution for the different practical uses. Considering the high cost of the alloys, we have refined some methods for evaluating the properties of precious alloys (or, better, we improved evaluation methods already used in different industry sectors), to obtain the data required to achieve this goal. Meno dettagli

Recrystallization affects both the structure and the mechanical properties of metals. The knowledge of recrystallization conditions for gold alloys is very important for optimizing the production process. Recrystallization conditions (temperature and time) depend on the type of alloy and the degree of deformation.
The following methods for determination of recrystallization characteristics will be compared: hardness measurements, metallographic investigation and differential thermal… Visualizza altro

Recrystallization affects both the structure and the mechanical properties of metals. The knowledge of recrystallization conditions for gold alloys is very important for optimizing the production process. Recrystallization conditions (temperature and time) depend on the type of alloy and the degree of deformation.
The following methods for determination of recrystallization characteristics will be compared: hardness measurements, metallographic investigation and differential thermal analysis. Samples are heat treated in cycles with temperature and time as variables. We will take into account 14kt yellow gold alloy. They are tested with different procedures to allow the comparison of methods for determining recrystallization characteristics. Meno dettagli

In modern melting and casting technology, the need for products able to front competition in the field of quality and price encourages the development of new alloys that can guarantee better performance. Most significant innovations have taken place in alloys for investment casting, to improve the quality of castings. Additions of many elements to gold alloys have been experimented, but only a few of them appear to be sufficiently effective and easy to use.
In this paper, we describe work… Visualizza altro

In modern melting and casting technology, the need for products able to front competition in the field of quality and price encourages the development of new alloys that can guarantee better performance. Most significant innovations have taken place in alloys for investment casting, to improve the quality of castings. Additions of many elements to gold alloys have been experimented, but only a few of them appear to be sufficiently effective and easy to use.
In this paper, we describe work carried out to examine technical and practical performances of some yellow 18 carat gold alloys (750‰ fineness) with additions aiming chiefly at improving alloy castability. Alloys of different composition have been tested and the effects of the different alloying additions have been compared, in order to find the addition elements that show better performance and able to give a true improvement of the quality level of the castings. Meno dettagli