scholarly journals Dimensional accuracy in quick plastic forming of aluminum alloy using demolding mechanism

2021 ◽  
Vol 13 (6) ◽  
pp. 168781402110217
Author(s):  
Chin-Wei Liu ◽  
Shyong Lee ◽  
Dean Chou ◽  
Shu-Han Hsu ◽  
Chun Lin Chu
Keyword(s):  
Dimensional Accuracy ◽  
Cnc Machining ◽  
Process Efficiency ◽  
Process Time ◽  
Metal Shell ◽  
Shell Mold ◽  
Operation Temperature ◽  
Temperature Loss ◽  
Plastic Forming ◽  
Quick Plastic Forming

This study focuses on quick plastic forming (QPF), product dimensional tolerances, and removal methods. The traditional curled metal shell mold in QFP, has limitations such as long process time and unstable quality. Therefore, this investigation designed a demolding mechanism, in order to improve the process efficiency and dimensional accuracy of QPF, in the manufacture of metal casings. The research results show that the proposed mechanism can significantly decrease the process time, because it replaces most of the operations of specimens movement after forming completely. The shorter process time reduce the die temperature loss during operation, thus also improving the efficiency by eliminating the need to wait for the die to return to its operation temperature. In terms of dimensional tolerance, the tolerance grade of QPF process was determined using the standard deviation, and found to be between IT10 and IT14. This range covers the scope of CNC cutting and stamping processing, indicating that the process has commercial value in the production of metal casings, because the current mainstream manufacturing process of metal casings comprises casting, stamping and CNC machining.

A New Technique for the Investigation of Tribological Behavior of Sliding Pairs Used in Hot Forming Processes

2008 ◽  
Author(s):  
Vjekoslav Franetovic
Keyword(s):  
Tribological Behavior ◽  
Hot Forming ◽  
New Technique ◽  
Aluminum Sheet ◽  
Forming Process ◽  
The Real ◽  
Plastic Forming ◽  
Quick Plastic Forming ◽  
A New Technique ◽  
Interacting Surfaces

Hot forming of aluminum sheet is highly influenced by the tribological behavior of the interacting surfaces of sliding pairs. Here we describe a new technique to investigate tribo-pair candidates for Quick Plastic Forming (QPF) and warm forming processes. This technique represents a bench type simulation of the real forming process where the sheet and tool interact by sliding against each other in a single motion (slide/stroke).

Sheet Orientation Effects on the Hot Formability Limits of Lightweight Alloys

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Fadi Abu-Farha ◽  
Louis G. Hector
Keyword(s):  
Rolling Direction ◽  
Superplastic Forming ◽  
Strain Ratio ◽  
Forming Limit ◽  
Specific Strain ◽  
Plastic Forming ◽  
Lightweight Alloys ◽  
Quick Plastic Forming ◽  
The Relationship ◽  
5083 Aluminum Alloy

The formability curves of AZ31B magnesium and 5083 aluminum alloy sheets were constructed using the pneumatic stretching test at two different sets of forming conditions. The test best resembles the conditions encountered in actual hydro/pneumatic forming operations, such as the superplastic forming (SPF) and quick plastic forming (QPF) techniques. Sheet samples were deformed at (400 °C and 1 × 10−3 s−1) and (450 °C and 5 × 10−3 s−1), by free pneumatic bulging into a set of progressive elliptical die inserts. The material in each of the formed domes was forced to undergo biaxial stretching at a specific strain ratio, which is simply controlled by the geometry (aspect ratio) of the selected die insert. Material deformation was quantified using circle grid analysis (CGA), and the recorded planar strains were used to construct the forming limit curves of the two alloys. The aforementioned was carried out with the sheet oriented either along or across the direction of major strains in order to establish the relationship between the material’s rolling direction and the corresponding limiting strains. Great disparities in limiting strains were found in the two orientations for both alloys; hence, a “composite FLD” is introduced as an improved means for characterizing material formability limits.

A Novel Tool Path Strategy for Modelling Complicated Perpendicular Curved Movements

2019 ◽  
Vol 796 ◽  
pp. 164-174 ◽  
Author(s):  
Bahman Meyghani ◽  
Mokhtar Awang
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Tool Path ◽  
Cnc Machining ◽  
Process Time ◽  
Efficient Tool ◽  
Element Modelling ◽  
Friction Stir ◽  
Tool Paths

Curved surfaces have been widely used in engineering applications such as friction stir welding (FSW), 5 axis CNC machining, and other processes. Therefore, the development of the finite element modelling of the complicated geometries has created a need to determine efficient tool paths. Previous finite element models modelled the single point movement of the tool. However, in industrial applications such as aerospace, mould and die, etc. the movement of the tool is complex. Proper determination of the tool path can lead to substantial savings of the process time, improvement of the workpiece surface quality and the improvement of the tool life, thereby leading to overall cost reduction and higher productivity. This paper presents a new approach for the determination of efficient tool paths in finite element modelling by using ABAQUS® software. VDISP user defined subroutine is used in order to define the complex curved movement of the tool. The results indicate that the method is appropriate for modelling of the tool path, and the tool always has a perpendicular position to the surface. Therefore, the method can be suitable for increasing the application of the finite element modelling in various industries.

Reverse Bulging in Hydro/Pneumatic Sheet Metal Forming Operations: Is it Worth It?

2010 ◽  
Author(s):  
Fadi Abu-Farha
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Thickness Distribution ◽  
Complex Part ◽  
Plastic Forming ◽  
Quick Plastic Forming ◽  
Time Savings ◽  
Direct Feedback ◽  
Specific Part

The merits of warm and elevated temperature hydro/pneumatic sheet metal forming operations, most prominently superplastic and quick plastic forming, have been ever counteracted by two major drawbacks: slow forming rates and non-uniform thickness distribution with potentially severe thinning. Trying to resolve one of the two issues has generally led to escalating the other, so a compromise based on the nature of the part being formed is often targeted. To tackle the latter of the two issues, imposing a pre-thinning reverse bulging step has been shown to ease the problem with specific part geometries that involve large plastic strains and intricate details. The aerospace industry, however, is the prime sector that is able to afford the “seemingly” prolonged forming times associated with this approach. Yet with the lack of adequate details on the implications of utilising reverse bulging, this effort explores some of the hidden merits of the approach. A recently-developed simple monitoring technique for providing a direct feedback on the sheet’s advancement during pneumatic forming operations, coupled with an interrupted testing methodology, are utilised to have a closer look at the process. The results reveal significant time-savings that can be achieved with the proper use of reverse bulging, for both simple and complex part geometries.

Simulation Based Development of Quick Plastic Forming

2005 ◽  
Author(s):  
Frank Lee ◽  
Krishna Murali ◽  
Andrew Heath ◽  
Raju Gandikota
Keyword(s):  
Simulation Based ◽  
Plastic Forming ◽  
Quick Plastic Forming

Numerical Study of Radiation and Temperature Phenomena for Improved Super-Plastic Sheet Metal Forming

2012 ◽  
Vol 735 ◽  
pp. 170-179
Author(s):  
Michal Mis ◽  
Richard Hall ◽  
Julian Spence ◽  
Nwabueze Emekwuru ◽  
Kevin Kibble
Keyword(s):  
Numerical Study ◽  
Process Efficiency ◽  
Work Piece ◽  
Heat Management ◽  
Selective Heating ◽  
Super Plastic ◽  
Plastic Forming ◽  
Improved Design ◽  
Super Plastic Forming ◽  
Accurate Temperature Control

In most super-plastic forming (SPF) investigations the focus is usually on the material aspects. In this paper the authors develop a model to improve the heat management of SPF. The model presented improved process possibilities. The improved design involves selective application of heat to the material. Final product shape can easily be controlled by accurate temperature control of the work piece. Numerical simulation has been carried out on various components including a ‘top hat shape‘ and a heat exchanger part. Simulation comparisons are made between selective heating and conventional processing, where all of the formed material is at the same temperature, and greater process efficiency of the selective heating approach is demonstrated.

Tribological Testing of Graphite and Boron Nitride Lubricant Formulations for High Temperature Aluminum Sheet Forming Processes

2007 ◽  
Author(s):  
M. David Hanna ◽  
Paul E. Krajewsk ◽  
James G. Schroth
Keyword(s):  
High Temperature ◽  
Boron Nitride ◽  
Superplastic Forming ◽  
Solid Lubricants ◽  
Sheet Forming ◽  
Aluminum Sheet ◽  
Plastic Forming ◽  
Quick Plastic Forming ◽  
Performance And Evaluation

The tribological behavior of AA5083 aluminum sheet sliding against tool steel impacts the quality of components manufactured with the elevated temperature metal forming processes such as Quick Plastic Forming (QPF), Superplastic Forming (SPF), or warm forming. This study focuses on the tribological performance and evaluation of alternative solid lubricants using a flat-on-flat tribo-tester to simulate sheet forming at high temperature applications. Improved lubricant formulations containing boron nitride with graphite additions were found to enhance lubricity while maintaining good adherence to the surface of the aluminum blank at a temperature of 450°C.

Quick Plastic Forming Behavior of AZ91 Magnesium Alloy Sheet

2011 ◽  
Vol 314-316 ◽  
pp. 842-846
Author(s):  
Gang Wang ◽  
Zhi Peng Zhang ◽  
Cheng Bo Liu ◽  
Xia Sheng
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Alloy Sheet ◽  
Gas Pressure ◽  
Test Results ◽  
Free Gas ◽  
Magnesium Alloy Sheet ◽  
Plastic Forming ◽  
Quick Plastic Forming ◽  
Bulging Test

The quick plastic forming (QPF) behavior for fine-grained AZ91D magnesium alloy sheet with the thickness of 1.0 mm and the grain size of 6.0 µm was investigated. Free gas bulging tests were conducted under different gas pressure for 300 s in the range of 250-400°C to investigate how the temperature and pressure impact on the formability of QPF. Free gas bulging test results show that the bulge height of semisphere part exist the peak value of 33 mm under the gas pressure of 0.5 MPa at 400°C. QPF tests of cup part were performed based on the free gas bulging test results. A cup part with the height of 20 mm which both of surface quality and fillet radius were satisfactory was formed using a two-stage loading path at 400°C during 300 s. Furthermore the microstructural revolution law during the QPF was discussed. The larger the thinning rate of parts is, the smaller the grain size will be.

Leaching Process of Cerium Extraction from Mixture of Cerite-Monazite Mineral

2006 ◽  
Vol 514-516 ◽  
pp. 1653-1657 ◽  
Author(s):  
José Cosme Cunha Gomes ◽  
C.P. Souza ◽  
Uilame Umbelino Gomes ◽  
Jean R. Gavarri ◽  
Jean P. Dallas ◽  
...  
Keyword(s):  
Heterogeneous Catalysts ◽  
Research Work ◽  
Sulfate Solution ◽  
Process Efficiency ◽  
Process Time ◽  
High Concentration ◽  
Acid Attack ◽  
Selective Precipitation ◽  
Leaching Process ◽  
Oxidation Of Hydrocarbons

Rare earth oxides have been widely investigated in catalysis as structured and electronic promoters to improve the activity and thermal stability of catalysts. Cerium has an important role in three-way catalysis and fluid catalytic cracking, two significant catalytic processes by their economic relevance and tonnage. Cerium and other rare earths have been studied as possible heterogeneous catalysts at selective oxidation of hydrocarbons. Cerite and monazite are minerals with high concentration of cerium element. Extraction of cerium metal using conventional leaching processes has shown low yields or high costs. The main purpose of this research work is to optimize the parameters in cerium purification stage from this mineral using leaching process. To separate particles with different granulometries, the mineral is ground and fractioned with sieves of 80, 200, 250 and 400 mesh. In order to put off organic components and oxidize cerium(III) to cerium(IV), samples were roasted at 1073K by twenty-four hours. The roasted samples were solubilized by acid attack (leaching) for approximately twenty-four hours; according to the acid used hydrochloric or sulfuric), cerium and other trivalent elements are solubilized as chloride or sulfate solution. Cerium was extracted by selective precipitation at pH~3,4 using ammonium or natrium hydroxide as pH changer. After filtration and drying, the precipitated product was characterized by XRD (x-ray diffraction), and then process efficiency was determined (cerium percentage and the different phases in the powder). Particles granulometry, roasting process (time and temperature), as well as leaching parameters (acid used, time, temperature and concentration of reagents) were the main variables studied.

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