Metallurgical Affects of Three Dimensional Printing Based Rapid Casting Solution

2011 ◽  
Vol 701 ◽  
pp. 1-8
Author(s):  
Rupinder Singh

Three dimensional printing (3DP) as rapid casting (RC) solutions has transformed over centuries from black art to science, but the metallurgical impinge on the process responsible for change in mechanical properties (like: surface finish, hardness, dimensional stability etc.) are still disputed. The purpose of the present research paper is to review metallurgical affect of 3DP based RC solution. The result of study suggests that prominent reason found to be responsible for improving the mechanical properties of RC is control of heat transfer rate while solidification (thus reducing dendrite formation).

2019 ◽  
Author(s):  
Anne Schmitz

Abstract The types of biomedical devices that can be three-dimensional printed (3DP) is limited by the mechanical properties of the resulting materials. As a result, much research has focused on adding carbon nanotubes (CNT) to these photocurable polymers to make them stronger. However, there is little to no data on how CNTs affect the impact resistance of these polymers, an important property when designing and manufacturing lower limb prosthetics. The objective of this study was to expand the use of 3DP to prosthetics by testing the hypothesis that adding CNTs to a stereolithographic (SLA) photocurable resin will result in a cured polymer with increased impact resistance. Twenty-six total specimens: 13 with nanotubes and 13 without nanotubes, were printed on a Form2 SLA printer. Once all the specimens were printed, washed, and cured, the impact resistance was quantified using a pendulum impact tester in a notched Izod configuration. Contrary to the hypothesis, the specimens with SWCNTs (0.312 ± 0.036 ft*lb/in) had a significantly lower impact resistance compared to the non-SWCNT specimens (0.364 ± 0.055 ft*lb/in), U = 34.0, p = 0.004. This decreased impact resistance may be due to voids in the printed polymer around the aggregated nanotubes. Thus, SLA polymers still do not have the impact strength needed to be used for a full lower limb prosthetic.


2019 ◽  
Vol 26 (6) ◽  
pp. 981-992
Author(s):  
Andrea Mantelli ◽  
Marinella Levi ◽  
Stefano Turri ◽  
Raffaella Suriano

Purpose The purpose of this study is to demonstrate the potential of three-dimensional printing technology for the remanufacturing of end-of-life (EoL) composites. This technology will enable the rapid fabrication of environmentally sustainable structures with complex shapes and good mechanical properties. These three-dimensional printed objects will have several application fields, such as street furniture and urban renewal, thus promoting a circular economy model. Design/methodology/approach For this purpose, a low-cost liquid deposition modeling technology was used to extrude photo-curable and thermally curable composite inks, composed of an acrylate-based resin loaded with different amounts of mechanically recycled glass fiber reinforced composites (GFRCs). Rheological properties of the extruded inks and their printability window and the conversion of cured composites after an ultraviolet light (UV) assisted extrusion were investigated. In addition, tensile properties of composites remanufactured by this UV-assisted technology were studied. Findings A printability window was found for the three-dimensional printable GFRCs inks. The formulation of the composite printable inks was optimized to obtain high quality printed objects with a high content of recycled GFRCs. Tensile tests also showed promising mechanical properties for printed GFRCs obtained with this approach. Originality/value The novelty of this paper consists in the remanufacturing of GFRCs by the three-dimensional printing technology to promote the implementation of a circular economy. This study shows the feasibility of this approach, using mechanically recycled EoL GFRCs, composed of a thermoset polymer matrix, which cannot be melted as in case of thermoplastic-based composites. Objects with complex shapes were three-dimensional printed and presented here as a proof-of-concept.


Author(s):  
J P Singh ◽  
R Singh

The purpose of the present investigation is to study the feasibility of decreasing the shell thickness for a statistically controlled rapid casting solution of lead alloy using three-dimensional printing technology. Starting from the identification of a component/benchmark, technological prototypes were produced with different shell thickness. Measurements on a coordinate measuring machine helped in calculating the dimensional tolerances of the castings produced. Some important mechanical properties were also compared to verify the suitability of the castings and further results are supported by microstructure analysis. The study suggested that the shell thickness having a value less than the recommended one is more suitable from a dimensional accuracy and an economic point of view. The provided data from the experimentation are extremely useful for the industrial application of the considered technology. The result indicates that at 1 mm shell thickness, the hardness of the casting improves from the recommended 12 mm. Further, production costs and production time have been reduced by 45.75 and 43 per cent, respectively, in comparison with the 12 mm recommended shell thickness.


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