scholarly journals Analysis of Causes of Porosity Change of Castings under the Influence of Variable Biscuit Height in the Filling Chamber

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6827
Author(s):  
Štefan Gašpár ◽  
Ján Majerník ◽  
Jan Kolínský
Keyword(s):  
Liquid Metal ◽  
Die Casting ◽  
Thermal Conditions ◽  
Casting Process ◽  
Flow Mode ◽  
Gating System ◽  
Quality Properties ◽  
Single Operation ◽  
Well Correlation ◽  
The Individual

Quality properties of castings produced in a die casting process correlate with porosity that is conditioned by a number of factors, which range from input melt quality to setup of technological factors of the die casting, and through structural design of the gating system. One of the primary parameters conditioning the inner soundness of the casting is the liquid metal dose per single operation of die casting. This paper examines the issue of metal dose. The experiments are performed with casting a gate system of an electromotor flange. The gating system examined was die cast with a variable volume of metal dose per single operation. The metal dose was adjusted to reach the height of a biscuit of 10, 20, and 30 mm. The examination of the inner homogeneity of the castings of the individual variants of gating systems with variable height of the biscuit proved that decreasing biscuit height results in an increase of porosity share in the casting volume. The programme MagmaSoft 5.4 revealed the main causes of changes in porosity share. The simulations detected that the change in biscuit height and volume of liquid metal directly influence thermal conditions of the melt in the filling chamber, and in the mould by means of the period in which the holding pressure action is influenced. Simultaneously, the melt flow mode in the sprues and gas entrapment in the melt volume are affected as well. Correlation of the factors consequently influences the final porosity of castings.

Development of Semi-Solid Die Casting Product Design and Die Design Technology for Aluminium Alloy Clamp

2016 ◽  
Vol 256 ◽  
pp. 334-339 ◽  
Author(s):  
Song Chen ◽  
Fan Zhang ◽  
You Feng He ◽  
Da Quan Li ◽  
Qiang Zhu
Keyword(s):  
Product Design ◽  
Die Casting ◽  
Casting Process ◽  
Die Design ◽  
Thick Wall ◽  
Thin Wall ◽  
Gating System ◽  
Cross Sectional ◽  
Die Casting Process ◽  
Semi Solid

Semi-solid slurry has significantly higher viscosity than liquid metal. This character of fluidity makes product design and die design, such as gating system, overflow and venting system, be different between these two die casting processes. In the present paper, taking a clamp product as an example, analyses the product optimization and die design by comparing the experimental and computational numerical simulation results. For the clamp, product structure is designed to be suitable for characters of SSM die casting process. The gating system is designed to be uniform variation of thickness, making the cross-sectional area uniformly reduce from the biscuit to the gate. This design ensures semi-solid metal slurry to fill die cavity from thick wall to thin wall. Gate position is designed at the thickest location, the gate shape of semi-solid die casting is set to be much bigger than traditional liquid casting. A good filling behaviour can be achieved by aforementioned all these design principles and it will be helpful to the intensification of pressure feeding after filling.

scholarly journals Numerical Simulation of Reoxidation Processes

2020 ◽  
Vol 328 ◽  
pp. 02007
Author(s):  
Marek Bruna ◽  
Marek Galčík
Keyword(s):  
Numerical Simulation ◽  
Liquid Metal ◽  
Aluminium Alloy ◽  
Oxide Layer ◽  
Negative Impact ◽  
Casting Process ◽  
Simulation Software ◽  
Gating System ◽  
Alloy Casting ◽  
Positive Effect

Reoxidation is one of the main problem accompanying the aluminium alloy casting process. The oxide layer created on the melt surface during reoxidation is entrained into the bulk of liquid metal and “bifilms” are created. Bifilms have negative impact on cast quality and internal homogenity of final casting. Paper aim is to clarify the reoxidation phenomenon by visualization with the aid of ProCAST numerical simulation software. Experiemtnal work deals with the design of several types of gating systems (non pressurized and naturally pressurized) with vortex elements in order to determine how these elements affect the reoxidation processes. Achieved results clearly confirmed the positive effect of the naturally pressurized gating system with vortex elements. The evaluation focuses mainly on melt velocity and amount of oxides created in gating system and in mold cavity.

scholarly journals Research and Evaluation of the Influence of the Construction of the Gate and the Influence of the Piston Velocity on the Distribution of Gases into the Volume of the Casting

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2264
Author(s):  
Ján Majerník ◽  
Štefan Gašpár ◽  
Jozef Husár ◽  
Ján Paško ◽  
Jan Kolínský
Keyword(s):  
Die Casting ◽  
Main Idea ◽  
Casting Process ◽  
Gating System ◽  
Technological Parameters ◽  
Piston Velocity ◽  
Casting Cycle ◽  
Suitable Structure ◽  
Filling Phase ◽  
Die Casting Process

Distribution of gasses to the cast volume and volume of pores can be maintained within the acceptable limits by means of correct setting of technological parameters of casting and by selection of suitable structure and gating system arrangement. The main idea of this paper solves the issue of suitability of die casting adjustment—i.e., change of technological parameters or change of structural solution of the gating system—with regards to inner soundness of casts produced in die casting process. Parameters which were compared included height of a gate and velocity of a piston. The melt velocity in the gate was used as a correlating factor between the gate height and piston velocity. The evaluated parameter was gas entrapment in the cast at the end of the filling phase of die casting cycle and at the same time percentage of porosity in the samples taken from the main runner. On the basis of the performed experiments it was proved that the change of technological parameters, particularly of pressing velocity of the piston, directly influences distribution of gasses to the cast volume.

A system for computer-aided gating design for multi-cavity die-casting dies

2015 ◽  
Vol 231 (11) ◽  
pp. 1983-1999 ◽  
Author(s):  
Vijay Kumar ◽  
Jatinder Madan
Keyword(s):  
System Design ◽  
Computer Aided Design ◽  
Die Casting ◽  
Casting Process ◽  
Manufacturing Cost ◽  
Gating System ◽  
Industrial Case Study ◽  
Efficient Manner ◽  
Die Casting Die ◽  
Computer Aided

The gating system design for a die-casting die is a non-trivial task that involves a number of steps and computations, in which many factors related to part design, material, and process need to be accounted. In case of a multi-cavity die-casting die, the non-triviality of the gating system design increases manifold. The main contribution of this article is to develop a computer-aided system for design of gating system for multi-cavity die-casting dies. The proposed system applies design knowledge and rules, accounting for various influencing factors to design gating system elements and generate their computer-aided design models in an efficient manner. To demonstrate the capabilities of the developed system, the results for an industrial case study part are presented. We expect that the proposed system would help reduce manufacturing cost and lead time, alongside bridging gaps between design and manufacturing of the die-casting process.

Modelling the pressure die casting process with the boundary element method: Die deformation model for flash prevention

1998 ◽  
Vol 212 (3) ◽  
pp. 197-215 ◽  
Author(s):  
J Milroy ◽  
S Hinduja ◽  
K Davey
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Die Casting ◽  
Injection Pressure ◽  
Casting Process ◽  
Operating Conditions ◽  
Deformation Model ◽  
The Individual ◽  
Pressure Die Casting ◽  
Element Method

In pressure die casting, the thermal loads, injection pressure and clamping forces cause the individual blocks of a die to deform. This deformation results in gaps between the interface surfaces which, if big enough and in the vicinity of the cavity, permit material to seep into the gaps, causing flash. This paper describes a thermoelastic model to predict the deformation of the die so that it can be machined to prevent flash. The model is based on the boundary element method and allows the use of linear isoparametric or quadratic subparametric elements. Each die block is analysed as a separate problem. To avoid the occurrence of flash, the model suggests the amounts that should be machined from each die block. The predicted deformation has been experimentally verified by measuring the profile of a test die using displacement transducers and die impressions. It is shown that there is good agreement between the predicted and experimental results for different operating conditions. By machining the amounts suggested by the model, the test die was run without flash at operating conditions that had previously resulted in flash.

Filling Pattern of Step Gating System in Lost Foam Casting Process and its Application

2012 ◽  
Vol 602-604 ◽  
pp. 1916-1921 ◽  
Author(s):  
Hong Zhou ◽  
Li Heng Luo
Keyword(s):  
Liquid Metal ◽  
Casting Process ◽  
Lost Foam Casting ◽  
Casting Defect ◽  
Gating System ◽  
Filling Process ◽  
Filling Pattern ◽  
Metal Volume ◽  
The Common ◽  
Lost Foam

To explore application of step gating system in LFC, filling process of two types of step gating system was simulated, their filling patterns were found, and several engineering examples were analyzed basing on these patterns. It was found the metal start filling through all ingates almost simultaneously if the gating system is open, otherwise the sequence of the ingate filling follow increasing sequence of streamline length from the inlet. It was also found the metal volume through each ingate increased gradually bottom-top when the common step gating system is filled by EPS, but when the common step gating system is open or step gating system have an auxiliary sprue, the metal volume decreases gradually. Analysis on several engineering examples shows the simulation confluence of two liquid metal fronts is basically in accordance with the casting defect locations.

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