scholarly journals Production and Subsequent Forming of Chip-Based Aluminium Sheets Without Remelting

2021 ◽  
Author(s):  
André Schulze ◽  
Oliver Hering ◽  
A. Erman Tekkaya
Keyword(s):  
Deep Drawing ◽  
Hot Extrusion ◽  
Tensile Tests ◽  
Cast Material ◽  
Process Route ◽  
New Process ◽  
Plastic Forming ◽  
Efficient Alternative ◽  
Sheet Products ◽  
Aluminium Sheets

AbstractBent components and deep drawn cups are produced by direct usage of aluminium chips without melting following a new process chain: hot extrusion of aluminium chips to a cylindrical open profile, flattening, subsequent rolling and bending or deep drawing. The properties of the hot extruded chip-based AA6060 sheets are examined by tensile tests and microstructural investigations and the results are compared with those obtained from material extruded from conventional cast billets. The chip-based sheets were used to form components by bending or deep drawing. No significant differences between the bent components or deep-drawn cups made of chips and those from cast material are observed regarding their capability for further plastic forming operations. This makes the new process route a resource-efficient alternative for the production of aluminium sheet products.

The Effect of Plastic Consolidation Parameters on the Microstructure and Mechanical Properties of Various Aluminium Powders

2011 ◽  
Vol 674 ◽  
pp. 141-146 ◽  
Author(s):  
Tomasz Tokarski
Keyword(s):  
Mechanical Properties ◽  
Research Work ◽  
Hot Extrusion ◽  
Tensile Tests ◽  
Material Strength ◽  
Cast Aluminum ◽  
Consolidation Process ◽  
Additional Material ◽  
Cast Material ◽  
Aluminum Powders

The present paper is aimed at investigations of mechanical properties and structure of technical purity aluminum powders prepared by plastic consolidation process. The research work is focused on effective improvement of mechanical properties of material while keeping the conductivity at high level. It is well known that application of rapid solidification method with hot extrusion technique leads to grain refinement, as so according to Hall-Petch rule, improvement in mechanical properties of material can be expected. Furthermore, additional material strength can be obtained by aluminum oxides from free surface of powders that became internal boundaries during consolidation process. Aluminum powders atomized by air, argon and water were cold compacted and extruded at temperatures of 325°C and 375°C. For comparison purposes the same extrusion conditions were applied to cast aluminum. In order to analyze effect of recrystalization process during hot extrusion operation, different extrusion temperatures were chosen. Tensile tests as well as micro-hardnes measurements showed significant increase in mechanical strength for RS samples in comparison to conventionally cast material. Structural observations by means of transmission electron microscopy revealed that grain size of materials extruded at the given temperature was at the same level, however amount and distribution of oxides particles differs significantly. It was considered that differences in strength between individual RS material were attributed to this effect.

Formability and Process Conditions of Magnesium Alloy Sheets

2005 ◽  
Vol 488-489 ◽  
pp. 453-456 ◽  
Author(s):  
Shi Hong Zhang ◽  
Yong Chao Xu ◽  
G. Palumbo ◽  
S. Pinto ◽  
Luigi Tricarico ◽  
...  
Keyword(s):  
Deep Drawing ◽  
Tensile Tests ◽  
Process Conditions ◽  
Drawing Ratio ◽  
Temperature Range ◽  
Fine Grained ◽  
Axial Tensile ◽  
Die Surface ◽  
Lower Temperature Range ◽  
Lower Temperature

Comparing the formability with each other, extrusion and various rolling experiments were carried out to make fine-grained AZ31 Mg sheets, and uni-axial tensile tests were carried out at different strain rates and temperatures to investigate the effect of different variables. A warm deep drawing tool setup with heating elements, which were distributed under the die surface and inside the blank holder, was designed and manufactured, and deep drawing was performed. Extruded Mg alloy AZ31 sheets exhibit the best deep drawing ability when working in the temperature range 250-350°C. Extruded and rolled sheets of 0.8 mm thick were also deep drawn in the lower temperature range 105-170°C，showing good formability and reaching a Limit Drawing Ratio up to 2.6 at 170°C for rolled sheets. At last, a sheet cup 0.4 mm thick was deep drawn successfully at 170 °C.

Laser Additive Manufacturing of Titanium Aluminides for Turbomachinery Applications

2019 ◽  
Author(s):  
Andreas Vogelpoth ◽  
Johannes Henrich Schleifenbaum ◽  
Silja Rittinghaus
Keyword(s):  
Titanium Aluminides ◽  
Tensile Tests ◽  
Total Elongation ◽  
Optical Microscope ◽  
Transient Temperature ◽  
Cast Material ◽  
Light Optical Microscope ◽  
Ct Analysis ◽  
Heat Treated Condition ◽  
High Cooling Rates

Abstract The defect-free processing of TiAl alloy TNM™-B1 by means of Laser Powder Bed Fusion (LPBF) is demonstrated by manufacturing of an automobile turbocharger wheel. Similar precision cast material was used as reference. TNM™-B1 was manufactured crack free with a density > 99.5% using elevated process temperatures above the brittle-to-ductile transient temperature (BDTT). The preheating temperature was provided by an induction preheating system. To minimize oxygen pick up during the LPBF process, the process atmosphere was actively cleaned using a gas-purification system. Produced test samples were analyzed in as-built and heat-treated condition regarding density, micro structure and phases by means of a Light Optical Microscope (LOM) and Scanning Electron Microscopy (SEM). Micro hardness was measured according to Vickers. Oxidation measurements were performed by means of carrier-gas hot extraction. Mechanical properties were determined using room temperature tensile tests. The final automobile turbocharger wheel was analyzed for defects using a Micro-Computer Tomography scanner (MCT). Besides bulk test samples, thin-walled specimens can be manufactured with sufficient density. Depending on the process parameters, an oxygen content < 1000 ppm could be reached. The as-built microstructure consists of lamellar (α2+γ) colonies and nearly globular γ as well as β/β0 at the grain boundaries. High cooling rates in the magnitude of 105 to 106 K/s provide small grain sizes of 1–7 μm. Hardness measurements reveal an increased hardness (515-560HV0.3) compared to cast material (390HV0.3). Samples for tensile tests show tensile strength around 840 MPa and a total elongation of 1.1% for LPBF-manufactured and hot isostatic pressed (HIP) samples. The CT analysis of the turbocharger wheel confirms that complex geometries made of TiAl can be additively manufactured free of cracks.

scholarly journals Process chain for the fabrication of hardenable aluminium-zirconium micro-components by deep drawing

2018 ◽  
Vol 190 ◽  
pp. 15013 ◽  
Author(s):  
Anastasiya Toenjes ◽  
Julien Kovac ◽  
Bernd Koehler ◽  
Axel von Hehl ◽  
Andreas Mehner ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Magnetron Sputtering ◽  
Deep Drawing ◽  
High Strength ◽  
Tensile Tests ◽  
Process Chain ◽  
Production Chain ◽  
Cold Forming ◽  
Industrial Sectors ◽  
Material State

Today, micro components are used in various industrial sectors such as electronics engineering and medical applications. The final quality of such parts depends on each individual step of the production chain from the manufacturing of semi-finished parts to the post-processing. In this study, magnetron sputtering is used to manufacture thin (15-30 μm) aluminium-zirconium alloy foils for the deep drawing of high strength and hardenable micro cups, which can be, for example, employed as micro valve caps. The development of a novel process chain for the production of these parts includes four different steps, beginning with the production of Al-Zr foils by magnetron sputtering. Secondly, tensile tests are performed with the foils in order to estimate their mechanical properties. Subsequently, micro deep drawing is used to produce the cup’s shape, and finally, a heat treatment in a drop-down tube furnace adjusts the cup’s hardness during fall. It is shown in particular that Al-Zr foils produced by magnetron sputtering have an attractive cold forming and hardening potential due to a microstructure consisting essentially of an oversaturated solid solution of zirconium in the aluminium matrix. This material state enables adequate formability and simplifies the heat treatment process since no solution annealing is required.

A new process route for the manufacturing of highly formed fiber-metal-laminates with elastomer interlayers (FMEL)

2019 ◽  
Vol 104 (1-4) ◽  
pp. 1293-1301 ◽  
Author(s):  
S. Roth ◽  
M. Stoll ◽  
K. A. Weidenmann ◽  
S. Coutandin ◽  
J. Fleischer
Keyword(s):  
Fiber Metal Laminates ◽  
Process Route ◽  
New Process ◽  
Fiber Metal

Thermal Deep Drawing of Magnesium Alloy Sheets

2014 ◽  
Vol 971-973 ◽  
pp. 220-223
Author(s):  
Bo Wang ◽  
Xian Chang Mao
Keyword(s):  
Magnesium Alloy ◽  
Deep Drawing ◽  
Development Trend ◽  
Alloy Sheet ◽  
Solid Particles ◽  
Blank Holder ◽  
Forming Technology ◽  
Warm Deep Drawing ◽  
Plastic Forming ◽  
The Development Trend

Thermal deep-drawing is a main processing technology which is used to plastic forming for magnesium alloy sheet. Combined with the research status, several deep drawing methods were introduced in detail in this paper, including indirect heating deep drawing, direct heating deep drawing, differential temperature deep drawing, warm hydraulic deep drawing, warm deep drawing with solid particles, warm deep drawing with segmental blank-holder, pre-forming warm deep drawing. Finally, the development trend and burning questions of magnesium alloy thermal forming technology were predicted.

Temperature and Processability of Magnesium Alloy AZ31 on Rectangular Cup Deep Drawing

2013 ◽  
Vol 535-536 ◽  
pp. 326-329 ◽  
Author(s):  
Yasuhide Nakayama ◽  
Tetsuo Naka ◽  
Takeshi Uemori ◽  
Ichiro Shimizu
Keyword(s):  
Magnesium Alloy ◽  
Numerical Simulations ◽  
Magnesium Alloys ◽  
Deep Drawing ◽  
Room Temperature ◽  
Local Heating ◽  
Plastic Strain Rate ◽  
Alloy Az31 ◽  
Magnesium Alloy Az31 ◽  
Plastic Forming

The magnesium alloys, that have high specific strength, are often applied to the industrial products. However, the magnesium alloys exhibit low ductility at the room temperature on account of its hexagonal close-packed structure. It is difficult to give large deformation to the magnesium alloys at room temperature. Therefore, the plastic forming of a magnesium alloy sheet needs the process at warm temperature. In the present work, the procedure of thermal-mechanical coupled analyses are employed. The numerical simulations of warm deep drawings have been performed in order to evaluate the dependence of the temperature on the plastic forming of a magnesium alloy AZ31 sheet. The mechanical properties of the magnesium alloy AZ31 shall be described as the functions depending on temperature. The shapes of punches and die holes are rectangle whose aspect ratios are 1.5 or 2.0. The corners of punches and dies are heated locally at 473K. The influence of local heating on the formability have been investigated. The relation between the blank size and the formability has been also estimated. As the results of numerical simulations, it was shown that the formability of deep drawing was improved by local heating to the punch and the die. When the blanks of various sizes were tried, the distributions of the plastic strain rate around the die corner were changed. Therefore, the deviation of the plastic flow and the temperature distribution arose in a sheet. Consequently, it is necessary to optimize the blank sizes according to the shape of die holes in addition to the forming temperature.

Pendeo-Epitaxy - A New Approach for Lateral Growth of Gallium Nitride Structures

1998 ◽  
Vol 537 ◽  
Author(s):  
Tsvetanka S. Zheleva ◽  
Scott A. Smith ◽  
Darren B. Thomson ◽  
Thomas Gehrke ◽  
Kevin J. Linthicum ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Selective Growth ◽  
Lateral Growth ◽  
Growth Technique ◽  
New Approach ◽  
Lateral Epitaxial Overgrowth ◽  
Process Route ◽  
Transmission Electron ◽  
New Process ◽  
Side Walls

AbstractA new process route for lateral growth of nearly defect free GaN structures via Pendeoepitaxy is discussed. Lateral growth of GaN films suspended from {1120} side walls of [0001] oriented GaN columns into and over adjacent etched wells has been achieved via MOVPE technique without the use of, or contact with, a supporting mask or substrate. Pendeo-epitaxy is proposed as the descriptive term for this growth technique. Selective growth was achieved using process parameters that promote lateral growth of the { 1120) planes of GaN and disallow nucleation of this phase on the exposed SiC substrate. Thus, the selectivity is provided by tailoring the shape of the underlying GaN layer itself consisting of a sequence of alternating trenches and columns, instead of selective growth through openings in SiO2 or SiNx mask, as in the conventional lateral epitaxial overgrowth (LEO).Two modes of initiation of the pendeo-epitaxial GaN growth via MOVPE were observed: Mode A - promoting the lateral growth of the {1120} side facets into the wells faster than the vertical growth of the (0001) top facets; and Mode B - enabling the top (0001) faces to grow initially faster followed by the pendeo-epitaxial growth over the wells from the newly formed {1120} side facets. Four-to-five order decrease in the dislocation density was observed via transmission electron microscopy (TEM) in the pendeo-epitaxial GaN relative to that in the GaN columns. TEM observations revealed that in pendeo-epitaxial GaN films the dislocations do not propagate laterally from the GaN columns when the structure grows laterally from the sidewalls into and over the trenches. Scanning electron microscopy (SEM) studies revealed that the coalesced regions are either defect-free or sometimes exhibit voids. Above these voids the PEGaN layer is usually defect free.

scholarly journals Multi-scale reinforcements stimulated dynamic recrystallization and mechanical behavior of as-extruded titanium matrix composites

2020 ◽  
Vol 321 ◽  
pp. 08005
Author(s):  
Peikun Qiu ◽  
Yuanfei Han ◽  
Guangfa Huang ◽  
Jianwen Le ◽  
Lihua Du ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Mechanical Behavior ◽  
Volume Fraction ◽  
Extrusion Direction ◽  
Hot Extrusion ◽  
Tensile Tests ◽  
Matrix Composites ◽  
Multi Scale ◽  
Complex Process ◽  
Submicron Scale

Different volume fraction of TiB, TiC and La2O3 multiple-reinforced Ti6Al4V composites were fabricated by casting and followed by forging and hot extrusion. The microstructural evolution and mechanical behavior of (TiB+TiC+La2O3)/Ti6Al4V composites during hot extrusion were investigated. The microstructural observations showed that the TiBw and TiCp agglomeration disappeared and distributed more homogeneously in the Ti matrix after hot extrusion. Besides, TiBw exhibited highly preferred alignment along the extrusion direction and TiCp distributed along the same direction. Besides, two kinds of microstructure bands with distinctive spatial distributions of reinforcements were formed after hot extrusion: equiaxial bands embedded with fairly substantial reinforcements and finer basket-weave bands containing few reinforcements, in which the micron-scale TiBw, TiCp and submicron-scale La2O3 particle stimulating nucleation occurred and resulting dynamic recrystallization were the main mechanisms responsible for grain refinement. The tensile tests revealed that hot extrusion significantly increased elongation of (TiB+TiC+La2O3)/Ti6Al4V composites from 2.71% to 13.2% accompanied by slightly decreasing ultimate tensile strength from 954MPa to 903MPa, compared with that of the as-forged composites, which due to a complex process of reinforcements/matrix interaction during extrusion and dynamic recrystallization.

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