scholarly journals Liquid Nitrogen in The Industrial Practice of Hot Aluminum Extrusion: Experimental and Numerical Investigation

2021 ◽  
Author(s):  
Riccardo Pelaccia ◽  
Barbara Reggiani ◽  
Marco Negozio ◽  
Lorenzo Donati
Keyword(s):  
Liquid Nitrogen ◽  
Extrusion Process ◽  
Die Design ◽  
Design Stage ◽  
Industrial Practice ◽  
Cooling Channels ◽  
Ram Speed ◽  
Aluminium Extrusion ◽  
Liquid Nitrogen Cooling ◽  
Good Agreement

Abstract Nowadays, the liquid nitrogen cooling in aluminium extrusion is a widely adopted industrial practice to increase the process productivity as well as to improve the extruded profile surface quality by reducing the profile exit temperatures. The cooling channels are commonly designed on the basis of die maker experience only, usually obtaining modest performances in terms of cooling efficiency. Trial-and-error approach is time and cost consuming, thus providing a relevant industrial interest in the development of reliable numerical simulations able to foresee and optimize the nitrogen cooling effect during the die design stage. In this work, an extensive experimental campaign was performed during the extrusion process of an AA6060 industrial hollow profile, in different conditions of nitrogen flow rate and ram speed. The monitored data (die and profile temperatures and extrusion load) were compared with the outputs of a fast and efficient numerical model proposed by the authors, and developed in the COMSOL Multiphysics code, able to compute not only the effect of nitrogen liquid flow but also the gaseous condition. The results of the simulations showed a good agreement with experimental data and evidenced how far was the experimental cooling channel design from an optimized condition.

scholarly journals Analysis and optimization of cooling channels performances for industrial extrusion dies

2021 ◽  
Author(s):  
Riccardo Pelacci ◽  
Marco Negozio ◽  
Barbara Reggiani ◽  
Lorenzo Donati ◽  
Luca Tomesani
Keyword(s):  
Liquid Nitrogen ◽  
Numerical Models ◽  
Extrusion Process ◽  
Die Design ◽  
Design Stage ◽  
Fe Model ◽  
Cooling Efficiency ◽  
Channel Design ◽  
Liquid Nitrogen Cooling ◽  
Experimental Trials

Liquid nitrogen cooling is widely used in the extrusion industrial practice in order to increase the production rate, to reduce the die temperature and to avoid defects on the profile exit surfaces resulting from an excessive heating. However, the efficiency of the cooling is deeply affected by position and design of the liquid nitrogen channel so that numerical modelling is gaining an increasing industrial interest in relation to the possibility offered to optimize the channel design without expensive and time-consuming experimental trials. In this work, a numerical FE model developed within COMSOL Multiphysics® is proposed and validated against experimental trials performed in industrial environment. The model combines the 3D simulation of the extrusion process with a 1D model of the cooling channel thus allowing the testing of a number of different solutions at the die design stage. The global aim of this work is the assessment of the liquid nitrogen cooling efficiency in the extrusion of an industrial aluminum profile and the proof of the potentials offered by numerical models to get an optimized channel design in terms of cooling efficiency, die thermal balancing and reduction of liquid nitrogen consumption.

Modeling of Ram Extrusion Process and Optimal Die Design

1996 ◽  
Author(s):  
Qingwen Deng ◽  
Yuyi Lin
Keyword(s):  
Analytical Model ◽  
Model Development ◽  
Optimization Procedure ◽  
Powdered Material ◽  
Extrusion Process ◽  
Die Design ◽  
Experimental Procedure ◽  
Extrusion Die ◽  
Powdered Coal ◽  
Good Agreement

Abstract This paper presents a one-dimensional analytical model of the ram extrusion process of a powdered material and a procedure for optimizing the shape of the extrusion die. Powdered coal mixed with water and asphalt was used as the extrudate material in the model development. The analytical model relates the pressure at the entrance of the die to the exit pressure of the die. Certain key parameters of the model were obtained from experiments. The comparison of the inlet pressure derived from the analytical model and the value obtained from the experimental procedure shown a good agreement. Optimization algorithms were applied to generate the ideal die shape. The objective is to minimize the power consumed in the extrusion process, while maintaining maximum strength for the extrudates. It is concluded from the study that the model and the optimization procedure developed for the model can be used in extrusion studies of other powdered materials.

Quantitative Analysis of the Extrusion Process of AZ31 Magnesium Alloy Based on Rough Set Theory and 3DFEM Simulation

2010 ◽  
Vol 455 ◽  
pp. 200-205 ◽  
Author(s):  
Yan Lou
Keyword(s):  
Product Quality ◽  
Set Theory ◽  
Rough Set ◽  
Rough Set Theory ◽  
Processing Parameters ◽  
Extrusion Process ◽  
Die Design ◽  
Average Weight ◽  
Billet Temperature ◽  
Ram Speed

The effect of extrusion process on the quality of AZ31 magnesium extrudate was performed, by data mining from 3DFEM simulation and Rough Set Theory(RST). The weight of the effect of processing parameters and die structures can be obtained to predict the product quality, to optimize the extrusion processing and the die design. The results show that the effect of the billet temperature on the product quality is dominate, and its average weight is 0.25. The second important parameter is the ram speed and its average weight is 0.21. The third is the extrusion ratio. Its average weight is 0.18. In addition, it was also found that the effect of the die characteristic parameters on the extrudate is insignificant. Finally, the rationality of the weight of effect was verified through experiments.

Analyses of Plastic Flow and Die Design during Hot Extrusion of Magnesium Alloy Strips

2010 ◽  
Vol 443 ◽  
pp. 98-103 ◽  
Author(s):  
Yeong-Maw Hwang ◽  
Shih Ming Tu
Keyword(s):  
Magnesium Alloy ◽  
Plastic Flow ◽  
Thickness Distribution ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Die Design ◽  
Thin Strip ◽  
Compression Tests ◽  
Ram Speed ◽  
Product Thickness

This study involves analyses and experiments of hot extrusion of magnesium alloy strips. Hot compression tests were firstly conducted to obtain the magnesium alloy’s plastic flow stresses at high temperatures. These data are used in the finite element simulations of the thin strip extrusion process. Using the FE simulations, the flow pattern of the magnesium alloy billet within the die, the temperature variation and the thickness distribution at the die exit were analyzed. The effects of different die bearing height design, initial billet temperatures and ram speed on the extrusion load, the temperature at the die exit and the product thickness distribution were also discussed. Finally, hot extrusion experiments were conducted and the experimental values of the extrusion load and dimensions of the products were compared with the analytical values to validate the analytical model. Sound products were obtained using the best designed bearing heights and other appropriate extrusion conditions.

Study of Temperature Evolution and Metal Flow of 6005A Aluminum Alloy during Indirect Extrusion

2011 ◽  
Vol 66-68 ◽  
pp. 164-169
Author(s):  
Ji Sen Qiao ◽  
Fi Li ◽  
Tian Dong Xia
Keyword(s):  
Heat Dissipation ◽  
Peak Load ◽  
Metal Flow ◽  
Extrusion Process ◽  
Temperature Evolution ◽  
Total Force ◽  
Steady Stage ◽  
Dead Metal Zone ◽  
Ram Speed ◽  
Good Agreement

A numerical model has been build up to study temperature evolution and metal flow for the indirect extrusion of 6005A aluminium alloy. Model validation was carried out by comparison between experiments and simulations. Results show a good agreement with each other. The influence of the extrusion parameters on the profile temperature and metal flow were studied according to the real industrialized process. It was found that the profile temperature increases with the ram speed as well as the peak load of the total press force. However, a too slow extrusion process would cause increasing of the total force at the end of the extrusion because of heat dissipation to the environment. In addition the dead metal zone at the top of the billet was shrunk during the extrusion process. The ram speed would have little influence on the distribution and shape changing of dead metal zone. Once the extrusion went into steady stage, the strain rate of metal flow would keep a stable situation relatively.

scholarly journals Effect of Process Variables on the Formation of Streak Defects on Anodized Aluminum Extrusions: An Overview

2012 ◽  
Vol 31 (2) ◽  
Author(s):  
Hanliang Zhu ◽  
Malcolm J. Couper ◽  
Arne K. Dahle
Keyword(s):  
Influencing Factors ◽  
Extrusion Process ◽  
Die Design ◽  
Process Variables ◽  
Anodized Aluminum ◽  
Industrial Practice ◽  
Billet Quality ◽  
Aluminum Extrusions ◽  
6Xxx Series ◽  
Processing Steps

AbstractStreak defects are often present on anodized extrusions of 6xxx series aluminum alloys, increasing the fabrication cost of these products. Moreover, streaking often only becomes visible after etching and anodizing treatments, rather than in the as-extruded condition, making it difficult to identify the original causes and influencing factors of these defects. In this paper, various process variables that influence the formation of streak defects on anodized aluminium extrusions are reviewed on the basis of a literature review, industrial practice and experimental results. The influencing factors involved in various processing steps such as billet quality, extrusion process, die design and etching process are considered. Effective measures for preventing the formation of streak defects in industrial extrusion products are discussed.

Numerical evaluation of hydrodynamic characteristics of planing hulls by using a hybrid method

2021 ◽  
pp. 147509022199024
Author(s):  
Emre Kahramanoglu ◽  
Silvia Pennino ◽  
Huseyin Yilmaz
Keyword(s):  
Experimental Data ◽  
Hybrid Method ◽  
Design Stage ◽  
Hydrodynamic Characteristics ◽  
Calm Water ◽  
Preliminary Design Stage ◽  
Reduction Function ◽  
Hull Forms ◽  
Good Agreement

The hydrodynamic characteristics of the planing hulls in particular at the planing regime are completely different from the conventional hull forms and the determination of these characteristics is more complicated. In the present study, calm water hydrodynamic characteristics of planing hulls are investigated using a hybrid method. The hybrid method combines the dynamic trim and sinkage from the Zarnick approach with the Savitsky method in order to calculate the total resistance of the planing hull. Since the obtained dynamic trim and sinkage values by using the original Zarnick approach are not in good agreement with experimental data, an improvement is applied to the hybrid method using a reduction function proposed by Garme. The numerical results obtained by the hybrid and improved hybrid method are compared with each other and available experimental data. The results indicate that the improved hybrid method gives better results compared to the hybrid method, especially for the dynamic trim and resistance. Although the results have some discrepancies with experimental data in terms of resistance, trim and sinkage, the improved hybrid method becomes appealing particularly for the preliminary design stage of the planing hulls.

Particle degradation in pneumatic conveyors: Use of data from a pilot-sized test facility to predict degradation in an industrial conveyor

2002 ◽  
Vol 216 (2) ◽  
pp. 65-71
Author(s):  
I Bridle ◽  
S R Woodhead
Keyword(s):  
Solid Material ◽  
Basmati Rice ◽  
Test Facility ◽  
Design Stage ◽  
Pneumatic Conveying ◽  
Process Industries ◽  
Industrial Practice ◽  
Use Of Data ◽  
Bulk Solid ◽  
Wide Range

Degradation of bulk solid product during pneumatic conveying is of concern in a range of process industries. However, prediction of product degradation levels at the conveyor design stage has proved challenging. This paper presents a proposed prediction technique, based on the use of a pilot-sized test facility to provide relevant empirical data. The results of experiments undertaken using malted barley, basmati rice, and granulated sugar are reported. For each bulk solid material, a wide range of conveying conditions have been examined, consistent with common industrial practice. Correlations between predictions and experimental data obtained in an industrial-scale conveyor are presented and discussed.

Quantitative Study on the Effect of Extrusion Process of AZ80 Magnesium Alloy

2010 ◽  
Vol 129-131 ◽  
pp. 1191-1195
Author(s):  
Yan Lou
Keyword(s):  
Set Theory ◽  
Rough Set ◽  
Rough Set Theory ◽  
Extrusion Process ◽  
Average Weight ◽  
Characteristic Parameters ◽  
Billet Temperature ◽  
Az80 Magnesium Alloy ◽  
Ram Speed

By data mining from 3DFEM simulation and Rough Set Theory (RST), it was performed that the extrusion process and die structures effect on the quality of AZ80 magnesium extrudate. The weights of the effect can be obtained. The results show that the effect of the billet temperature on the product quality is dominate, and its average weight is 0.27. The second important parameter is the ram speed and its average weight is 0.22. In addition, it was also found that the effect of the die characteristic parameters on the extrudate is insignificant.

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