Investigation of Interface Agent for Investment Casting With Ice Patterns

2005 ◽  
Vol 128 (2) ◽  
pp. 554-562 ◽  
Author(s):  
Qingbin Liu ◽  
Ming C. Leu

Investment casting with ice patterns is similar to that with wax patterns but with significant process differences. A major difference in our developed method is that an interface agent needs to be coated around the ice pattern to protect it from damage during the process. We have studied the criteria for choosing the interface agent and discovered that the most important factor is the cohesion parameter. The thickness of the interface agent affects the dimensional accuracy of the generated metal casting. To compensate for this, mathematical models have been constructed to predict the thickness of the interface agent for a large cylindrical part and for a small part. The interface layer thickness and the temperature distribution within the ice part and the solidifying interface agent have been investigated. For solid ice cylinders, both the immersion time and the cylinder diameter affect the interface layer thickness. For small parts, the interface thickness is mainly dependent upon the ratio between the volume and surface area of the ice part and to a lesser extent upon the physical properties of the materials. Superheat has little influence on the interface layer thickness. Based on the analysis, the dimensional accuracy of the metal castings for small parts can be much improved by compensating the interface layer thickness. The analytical results agree well with experimental observations.

2020 ◽  
Vol 26 (9) ◽  
pp. 1535-1554
Author(s):  
Swapnil Vyavahare ◽  
Shailendra Kumar ◽  
Deepak Panghal

Purpose This paper aims to focus on an experimental study of surface roughness, dimensional accuracy and time of fabrication of parts produced by fused deposition modelling (FDM) technique of additive manufacturing. The fabricated parts of acrylonitrile butadiene styrene (ABS) material have pyramidal and conical features. Influence of five process parameters of FDM, namely, layer thickness, wall print speed, build orientation, wall thickness and extrusion temperature is studied on response characteristics. Furthermore, regression models for responses are developed and significant process parameters are optimized. Design/methodology/approach Comprehensive experimental study is performed using response surface methodology. Analysis of variance is used to investigate the influence of process parameters on surface roughness, dimensional accuracy and time of fabrication in both outer pyramidal and inner conical regions of part. Furthermore, a multi-response optimization using desirability function is performed to minimize surface roughness, improve dimensional accuracy and minimize time of fabrication of parts. Findings It is found that layer thickness and build orientation are significant process parameters for surface roughness of parts. Surface roughness increases with increase in layer thickness, while it decreases initially and then increases with increase in build orientation. Layer thickness, wall print speed and build orientation are significant process parameters for dimensional accuracy of FDM parts. For the time of fabrication, layer thickness and build orientation are found as significant process parameters. Based on the analysis, statistical non-linear quadratic models are developed to predict surface roughness, dimensional accuracy and time of fabrication. Optimization of process parameters is also performed using desirability function. Research limitations/implications The present study is restricted to the parts of ABS material with pyramidal and conical features only fabricated on FDM machine with delta configuration. Originality/value From the critical review of literature it is found that some researchers have made to study the influence of few process parameters on surface roughness, dimensional accuracy and time of fabrication of simple geometrical parts. Also, regression models and optimization of process parameters has been performed for simple parts. The present work is focussed on studying all these aspects in complicated geometrical parts with pyramidal and conical features.


Alloy Digest ◽  
1973 ◽  
Vol 22 (12) ◽  

Abstract CANNON-MUSKEGON 8620 is a low-carbon triple-alloy steel capable of being carburized for wear resistance or heat treated for toughness. This steel is suitable for many engineering applications, and is used in large quantities in the investment casting industry for small parts. A higher silicon content is permissible in this steel than in AISI 8620 (wrought) alloy steel. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, joining, and surface treatment. Filing Code: SA-299. Producer or source: Cannon-Muskegon Corporation.


Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1581 ◽  
Author(s):  
Eustaquio García Plaza ◽  
Pedro Núñez López ◽  
Miguel Caminero Torija ◽  
Jesús Chacón Muñoz

The evolution of fused filament fabrication (FFF) technology, initially restricted to the manufacturing of prototypes, has led to its application in the manufacture of finished functional products with excellent mechanical properties. However, FFF technology entails drawbacks in aspects, such as dimensional and geometric precision, and surface finish. These aspects are crucial for the assembly and service life of functional parts, with geometric qualities lagging far behind the optimum levels obtained by conventional manufacturing processes. A further shortcoming is the proliferation of low cost FFF 3D printers with low quality mechanical components, and malfunctions that have a critical impact on the quality of finished products. FFF product quality is directly influenced by printer settings, material properties in terms of cured layers, and the functional mechanical efficiency of the 3D printer. This paper analyzes the effect of the build orientation (Bo), layer thickness (Lt), feed rate (Fr) parameters, and plate-extruder movements on the dimensional accuracy, flatness error, and surface texture of polylactic acid (PLA) using a low cost open-source FFF 3D printer. The mathematical modelling of geometric properties was performed using artificial neural networks (ANN). The results showed that thinner layer thickness generated lower dimensional deviations, and feed rate had a minor influence on dimensional accuracy. The flatness error and surface texture showed a quasi-linear behavior correlated to layer thickness and feed rate, with alterations produced by 3D printer malfunctions. The mathematical models provide a comprehensive analysis of the geometric behavior of PLA processing by FFF, in order to identify optimum print settings for the processing of functional components.


Author(s):  
Haihua Wu ◽  
Yu Sun ◽  
Jianhui Peng ◽  
Caihua Huang ◽  
Xicong Ye

Graphite flake/phenolic resin powder mixture had been prepared via selective laser sintering process. A dimensional analysis involving radial and axial deviation was performed, and the effect of SLS process parameters (laser power, scan spacing, scan speed, layer thickness) in both radial and axial directions were investigated. Laser power is found to be the most significant process variable in radial dimensional accuracy, while in axial direction layer thickness and laser power are the most significant process variable by range analysis based on orthogonal experiment. The optimum combination of parameters in graphite flake/phenolic resin powders mixture SLS process for high dimensional accuracy in radial direction was laser power, scan speed, scan spacing, and layer thickness of 20 W, 1500 m/s, 0.1 mm, and 0.1 mm, respectively, while the optimum combination of parameters in axial direction was laser power, scan speed, scan spacing, and layer thickness of 20 W, 2000 mm/s, 0.1 mm, and 0.15 mm, respectively. Energy density was introduced to better incorporate the processing parameters with dimensional accuracy and mechanical properties, and both dimensional accuracy and bending strength were analyzed under varying energy density and layer thickness, and results showed that in the range of energy density of 0.075–0.15 J/mm2, layer thickness of 0.1–0.2 mm, a graphite flake/phenolic resin laser sintered part with appropriate bending strength and dimensional accuracy could be prepared.


2015 ◽  
Vol 667 ◽  
pp. 200-205
Author(s):  
Yan Ling Guo ◽  
Yue Qiang Yu ◽  
Kai Yi Jiang

. Based on orthogonal test, the forming accuracy and density of laser sintering eucalyptus/PES blend is studied in this paper. It mainly analysed the effect of the powder size and process parameters (such as laser power, layer thickness, preheating temperature, etc) on the forming precision and density of sintered eucalyptus/PES parts, also the correlation analysis of molding error caused by the powder’s physical properties and machine is performed. By measuring the parts’ dimensions, the results show that the laser power and powder size are two main factors influencing parts’ density, and variable density, layer thickness and preheating temperature jointly affect the dimensional accuracy. The optimized processing parameters are obtained. The powder size, laser power, scanning rate, layers thickness and preheating temperature are 300 mesh, 43W, 2000mm/s, 0.1mm, 60°C respectively.


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