Filling system for investment cast Ni-base turbine blades

Li, D.Z; Campbell, John B.; Li, Y.Y

doi:10.1016/j.jmatprotec.2004.02.032

Cited by 63 publications

(24 citation statements)

References 7 publications

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“…Most of the work was based on porosity and its effect over the mechanical properties. Therefore, many researchers investigated the formation of pores during casting [1][2][3][4][5][6]. The main source of porosity in aluminium castings was blamed to be hydrogen which has a high solubility in liquid but very low in solid.…”

Section: Introductionmentioning

confidence: 99%

Quality Evaluation of Remelted A356 Scraps

Yüksel¹,

Tamer²,

Erzi³

et al. 2016

Archives of Foundry Engineering

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A356 is one of the widely used aluminium casting alloy that has been used in both sand and die casting processes. Large amounts of scrap metal can be generated from the runner systems and feeders. In addition, chips are generated in the machined parts. The surface area with regard to weight of chips is so high that it makes these scraps difficult to melt. Although there are several techniques evolved to remedy this problem, yet the problem lies in the quality of the recycled raw material. Since recycling of these scrap is quite important due to the advantages like energy saving and cost reduction in the final product, in this work, the recycling efficiency and casting quality were investigated. Three types of charges were prepared for casting: %100 primary ingot, %100 scrap aluminium and fifty-fifty scrap aluminium and primary ingot mixture were used. Melt quality was determined by calculating bifilm index by using reduced pressure test. Tensile test samples were produced by casting both from sand and die moulds. Relationship between bifilm index and tensile strength were determined as an indication of correlation of melt quality. It was found that untreated chips decrease the casting quality significantly. Therefore, prior to charging the chips into the furnace for melting, a series of cleaning processes has to be used in order to achieve good quality products.

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Section: Introductionmentioning

confidence: 99%

Quality Evaluation of Remelted A356 Scraps

Yüksel¹,

Tamer²,

Erzi³

et al. 2016

Archives of Foundry Engineering

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“…Although in this study the best fill was achieved in the top-gated system, it should be noted that it is generally reported in the literature that bottom-gated systems produce castings with lower defect densities. 30 The state of the art simulation software today uses the volume of fluid algorithm which assumes all fill fronts are diffuse and the effect of surface tension is normally not captured. In the current study it was shown that for thinwalled sections this is important as the ability to fill thin sections is heavily influenced by the surface tension which is consistent with previously established fillability concept.…”

Section: Resultsmentioning

confidence: 99%

Effects of Process Related Variations on Fillablity Simulation of Thin-Walled IN718 Structures

et al. 2017

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Simulation tools have improved significantly and are now capable of accurately predicting mould filling behavior. The quality of prediction is highly dependent on material properties and set-up of boundary conditions for the simulation. In this work material properties were measured and casting conditions were analyzed to accurately replicate the casting process in simulation. The sensitivity of the predictions to minor process variations commonly found in foundries was evaluated by comparing simulation and cast samples. The observed discrepancies between simulation and cast samples were evaluated and discussed in terms of their dependency on process variations. It was concluded that the simulation set-up was capable of reasonable predictions and could replicate the asymmetry of the filling however did not accurately predict the absolute value of the unfilled area. It was discovered that asymmetric flow due to variations in the orientation of the casting mould during filling could have greater influence on the predictions than the actual variation in fill time. The quality of simulation is dependent on equipment and techniques used in the foundry as well as the metallurgical model to simulate the process.

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“…Smooth surfaces were obtained for all cast specimens. The successful elimination of defects resulted from a good design of gating system, ceramic shell molds, and casting parameters (i.e., pouring temperature and preheating temperature for shell molds) [2].…”

Section: Experimental Methodsmentioning

confidence: 99%

“…However the microstructure and mechanical properties of cast products highly depend on alloys, ceramic shell, gating system solidification process. The failure rate in production of the impeller by investment casting has been 30-40% [2]. Some defects commonly appear in products of investment casting: these include misruns, inclusion, macro and micro porosity and hot cracks [3,4].…”

Section: Introductionmentioning

confidence: 99%