scholarly journals Feasibility of Calcium Sulfate Moulds Made by Inkjet 3D Printing for Rapid Casting of Aluminium Alloys

Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 802 ◽  
Author(s):  
Pablo Rodríguez-González ◽  
Pablo Eduardo Robles Valero ◽  
Ana Isabel Fernández-Abia ◽  
María Ángeles Castro-Sastre ◽  
Joaquín Barreiro García
Keyword(s):  
3D Printing ◽  
Aluminium Alloys ◽  
Casting Process ◽  
Sand Casting ◽  
Filling Process ◽  
Critical Aspect ◽  
Dimensional Precision ◽  
Filling System ◽  
Staircase Effect ◽  
Design Freedom

In this research, a comparative analysis has been carried out between a traditional sand casting process and a modern mould obtained by additive manufacturing (AM), in the context of aluminium parts production. In this case of AM, an inkjet 3D printing (3DP) process allowed us to create a ceramic mould. A numerical simulation was carried out to study the filling and cooling rates of both parts. The design freedom typical of the 3DP technique allowed us to optimize the filling system. The results showed that in sand moulding, the speed in the gate suddenly increased when the liquid metal entered the part cavity, leading to severe turbulence due to the fountain effect. The input of air is related to the speed in the gate. Nevertheless, the results showed that when using the 3DP mould, the speed in the gate remained constant and the filling process was homogenous. With regard to the dimensional precision, while the staircase effect in the surface of the 3DP mould is the most critical aspect to control, in the sand casting mould the critical aspect is the dimensional precision of the pattern. Microstructures of the cross-section of the moulded parts showed folded shapes and air input in sand casting, which could be produced by the severe turbulence and the oxide film present in the melt during the filling process. On the other hand, the porosity found in parts produced with the 3DP mould corresponds to shrinkage; during the filling process, the remaining binder is vaporized, creating nucleation points. In this way, pores are formed by shrinkage and a mixture of shrinkage and gas entrapment. With these considerations, it can be concluded that AM shows feasibility and advantages as an alternative to the sand casting method for aluminium alloys.

scholarly journals Application of Vacuum Techniques in Shell Moulds Produced by Additive Manufacturing

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1090
Author(s):  
P. Rodríguez-González ◽  
P. E. Robles Valero ◽  
A. I. Fernández-Abia ◽  
M. A. Castro-Sastre ◽  
J. Barreiro García
Keyword(s):  
Additive Manufacturing ◽  
Cross Section ◽  
Dimensional Accuracy ◽  
Filling Process ◽  
Critical Aspect ◽  
Entire Surface ◽  
Vacuum Suction ◽  
Staircase Effect ◽  
Gas Entrapment ◽  
Binder Jetting

This research shows the feasibility of the additive manufacturing technique (AM), Binder Jetting (BJ), for the production of shell moulds, which are filled by vacuum suction in the field of aluminium parts production. In addition, this study compares the gravity pouring technique and highlights the advantages of using vacuum techniques in AM moulds. A numerical simulation was carried out to study the behaviour of the liquid metal inside the moulds and the cooling rate of parts was analysed. The results show that in the gravity-pouring mould, the velocity in the gate causes moderate turbulence with small waves. However, vacuum suction keeps the velocity constant by eliminating waves and the filling process is homogeneous. Regarding dimensional accuracy, the staircase effect on the surface of the 3D moulds was the most critical aspect. The vacuum provides very homogeneous values of roughness across the entire surface of the part. Similarly, 3D scanning of castings revealed more accurate dimensions thanks to the help of vacuum forces. Finally, the microstructure of the cross section of the moulded parts shows that the porosity decreases with the vacuum filled. In both cases, the origin of the pores corresponds to gas entrapment and shrinkage during the filling process, the binder vaporization and nucleation points creation, leading to pores by shrinkage, gas entrapment or a mixture of both. This is the first study that uses vacuum filling techniques in moulds created by BJ, demonstrating the feasibility and advantages of AM using vacuum techniques, as an alternative to traditional casting.

scholarly journals Effect of Solidification Rates at Sand Casting on the Mechanical Joinability of a Cast Aluminium Alloy

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1304
Author(s):  
Moritz Neuser ◽  
Olexandr Grydin ◽  
Anatolii Andreiev ◽  
Mirko Schaper
Keyword(s):  
Mechanical Properties ◽  
Aluminium Alloy ◽  
Aluminium Alloys ◽  
High Strength ◽  
Casting Process ◽  
Sand Casting ◽  
Minimum Thickness ◽  
Cast Aluminium ◽  
Microstructure Parameters ◽  
Alloys Of The Al

Implementing the concept of mixed construction in modern automotive engineering requires the joining of sheet metal or extruded profiles with cast components made from different materials. As weight reduction is desired, these cast components are usually made from high-strength aluminium alloys of the Al-Si (Mn, Mg) system, which have limited weldability. The mechanical joinability of the cast components depends on their ductility, which is influenced by the microstructure. High-strength cast aluminium alloys have relatively low ductility, which leads to cracking of the joints. This limits the range of applications for cast aluminium alloys. In this study, an aluminium alloy of the Al-Si system AlSi9 is used to investigate relationships between solidification conditions during the sand casting process, microstructure, mechanical properties, and joinability. The demonstrator is a stepped plate with a minimum thickness of 2.0 mm and a maximum thickness of 4.0 mm, whereas the thickness difference between neighbour steps amounts to 0.5 mm. During casting trials, the solidification rates for different plate steps were measured. The microscopic investigations reveal a correlation between solidification rates and microstructure parameters such as secondary dendrite arm spacing. Furthermore, mechanical properties and the mechanical joinability are investigated.

OPTIMISATION OF SAND CASTING PROCESS FOR IMPELLER USING TAGUCHI METHODOLOGY

2020 ◽  
Vol XVII (2) ◽  
pp. 23-33
Author(s):  
Faisal Hafeez ◽  
Salman Hussain ◽  
Wasim Ahmad ◽  
Mirza Jahanzaib
Keyword(s):  
Surface Roughness ◽  
Surface Defects ◽  
A356 Alloy ◽  
Casting Process ◽  
Sand Casting ◽  
Gate Length ◽  
Taguchi Methodology ◽  
Confirmatory Tests ◽  
Binder Ratio ◽  
Response Measures

This paper presents the study to investigate the effects of binder ratio, in-gate length and pouring height on hardness, surface roughness and casting defects of sand casting process. Taguchi methodology with L9 orthogonal array was employed to design the experimentation. Sand casting of six blade impeller using A356 alloy was performed and empirical models for all the above response measures were formulated. Confirmatory tests and analysis of variance results confirmed the accuracy of the model. Binder ratio was found to be the most significant parameter affecting casting surface defects and surface roughness. This was followed by pouring height and in-gate length.

scholarly journals Experimental and simulation analysis on multi-gate variants in sand casting process

2021 ◽  
Vol 62 ◽  
pp. 119-131
Author(s):  
I. Rajkumar ◽  
N. Rajini ◽  
A. Alavudeen ◽  
T. Ram Prabhu ◽  
S.O. Ismail ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Casting Process ◽  
Sand Casting

Thermal optimisation in the sand casting process

2001 ◽  
Vol 18 (3/4) ◽  
pp. 392-417 ◽  
Author(s):  
R.W. Lewis ◽  
M.T. Manzari ◽  
D.T. Gethin
Keyword(s):  
Casting Process ◽  
Sand Casting
Sign in / Sign up

Export Citation Format

Share Document