Microstructural Assessment of a Multiple-Intermetallic-Strengthened Aluminum Alloy Produced from Gas-Atomized Powder by Hot Extrusion and Friction Extrusion

Tianhao Wang; Bharat Gwalani; Joshua Silverstein; Jens Darsell; Saumyadeep Jana; Timothy Roosendaal; Angel Ortiz; Wayne Daye; Tom Pelletiers; Scott Whalen

doi:10.3390/ma13235333

Microstructural Assessment of a Multiple-Intermetallic-Strengthened Aluminum Alloy Produced from Gas-Atomized Powder by Hot Extrusion and Friction Extrusion

Materials ◽

10.3390/ma13235333 ◽

2020 ◽

Vol 13 (23) ◽

pp. 5333

Author(s):

Tianhao Wang ◽

Bharat Gwalani ◽

Joshua Silverstein ◽

Jens Darsell ◽

Saumyadeep Jana ◽

...

Keyword(s):

Elevated Temperatures ◽

Solid Phase ◽

Hot Extrusion ◽

Extrusion Process ◽

High Temperature Strength ◽

Aluminum Powders ◽

Specific Strength ◽

Friction Extrusion ◽

Processing Techniques ◽

Al Matrix

An aluminum (Al) matrix with various transition metal (TM) additions is an effective alloying approach for developing high-specific-strength materials for use at elevated temperatures. Conventional fabrication processes such as casting or fusion-related methods are not capable of producing Al–TM alloys in bulk form. Solid phase processing techniques, such as extrusion, have been shown to maintain the microstructure of Al–TM alloys. In this study, extrusions are fabricated from gas-atomized aluminum powders (≈100–400 µm) that contain 12.4 wt % TM additives and an Al-based matrix reinforced by various Al–Fe–Cr–Ti intermetallic compounds (IMCs). Two different extrusion techniques, conventional hot extrusion and friction extrusion, are compared using fabricating rods. During extrusion, the strengthening IMC phases were extensively refined as a result of severe plastic deformation. Furthermore, the quasicrystal approximant IMC phase (70.4 wt % Al, 20.4 wt % Fe, 8.7 wt % Cr, 0.6 wt % Ti) observed in the powder precursor is replaced by new IMC phases such as Al3.2Fe and Al45Cr7-type IMCs. The Al3Ti-type IMC phase is partially dissolved into the Al matrix during extrusion. The combination of linear and rotational shear in the friction extrusion process caused severe deformation in the powders, which allowed for a higher extrusion ratio, eliminated linear voids, and resulted in higher ductility while maintaining strength comparable to that resulting from hot extrusion. Results from equilibrium thermodynamic calculations show that the strengthening IMC phases are stable at elevated temperatures (up to ≈ 600 °C), thus enhancing the high-temperature strength of the extrudates.

Download Full-text

Lightweight in Automotive Components by Forming Technology

Automotive Innovation ◽

10.1007/s42154-020-00103-3 ◽

2020 ◽

Vol 3 (3) ◽

pp. 195-209 ◽

Cited By ~ 4

Author(s):

Stephan Rosenthal ◽

Fabian Maaß ◽

Mike Kamaliev ◽

Marlon Hahn ◽

Soeren Gies ◽

...

Keyword(s):

High Performance ◽

Lightweight Design ◽

Dissimilar Materials ◽

Hot Extrusion ◽

High Strength ◽

Extrusion Process ◽

Specific Strength ◽

Metal Metal ◽

Fiber Metal ◽

Strength And Stiffness

AbstractLightweight design is one of the current key drivers to reduce the energy consumption of vehicles. Design methodologies for lightweight components, strategies utilizing materials with favorable specific properties and hybrid materials are used to increase the performance of parts for automotive applications. In this paper, various forming processes to produce light parts are described. Material lightweight design is discussed, covering the manufacturing processes to produce hybrid components like fiber–metal, polymer–metal and metal–metal composites, which can be used in subsequent deep drawing or combined forming processes. Approaches to increasing the specific strength and stiffness with thermomechanical forming processes as well as the in situ control of the microstructure of such components are presented. Structure lightweight design discusses possibilities to plastically form high-strength or high-performance materials like magnesium or titanium in sheet, profile and tube forming operations. To join those materials and/or dissimilar materials, new joining by forming technologies are shown. To economically produce lightweight parts with gears or functional elements, incremental sheet-bulk metal forming is presented. As an important part property, the damage evolution during the forming operations will be discussed to enable even lighter parts through a more reliable design. New methods for predicting and tailoring the mechanical properties like strength and residual stresses will be shown. The possibilities of system lightweight design with forming technologies are presented. A combination of additive manufacturing and forming to produce highly complex parts with integrated functions will be shown. The integration of functions by a hot extrusion process for the manufacturing of shape memory alloys is presented. An in-depth understanding of the newly developed processes, methodologies and effects allows for a more accurate dimensioning of components. This facilitates a reduction in the total mass and an increasing performance of vehicle components.

Download Full-text

Fabrication of Aluminum/Aluminum Nitride Composites by Reactive Mechanical Alloying

Materials Science Forum ◽

10.4028/www.scientific.net/msf.534-536.181 ◽

2007 ◽

Vol 534-536 ◽

pp. 181-184

Author(s):

Seung Hoon Yu ◽

Kwang Seon Shin

Keyword(s):

Mechanical Properties ◽

Mechanical Alloying ◽

Elevated Temperatures ◽

Hot Extrusion ◽

Extrusion Process ◽

Processing Technique ◽

Compression Tests ◽

Composite Powders ◽

Al Matrix Composites

Various reactions and the in-situ formation of new phases can occur during the mechanical alloying process. In the present study, Al powders were strengthened by AlN, using the in-situ processing technique during mechanical alloying. Differential thermal analysis and X-ray diffraction studies were carried out in order to examine the formation behavior of AlN. It was found that the precursors of AlN were formed in the Al powders and transformed to AlN at temperatures above 600oC. The hot extrusion process was utilized to consolidate the composite powders. The composite powders were canned in an Al can and then extruded at elevated temperatures. The microstructure of the extrusions was examined by SEM and TEM. In order to investigate the mechanical properties of the extrusions, compression tests and hardness measurements were carried out. It was found that the mechanical properties and the thermal stability of the Al/AlN composites were significantly greater than those of conventional Al matrix composites.

Download Full-text

Optimization of Hot Extrusion Process Parameters Using Taguchi Based Grey Relation Analysis

International Journal of Materials Forming and Machining Processes ◽

10.4018/ijmfmp.2019010101 ◽

2019 ◽

Vol 6 (1) ◽

pp. 1-18

Author(s):

Sarojini Jajimoggala

Keyword(s):

Process Parameters ◽

Low Cost ◽

Hot Extrusion ◽

Processing Parameters ◽

Extrusion Process ◽

Optimal Process ◽

Optimal Processing ◽

Processing Variables ◽

Extruded Products ◽

Processing Techniques

Enormous applications of aluminium alloys in various key industries necessitated the development and improvement of material processing techniques. Due to simplicity in making complex shapes and low cost of production, the extrusion process for aluminium has gained great popularity in recent years. As the processing variables/parameters during any manufacturing process significantly effects the yield and mechanical properties of extruded products, the development of optimal process parameters combination is found to be vital for the modern manufacturing industries. Hence, the present article addresses the conducting of hot extrusion experiments with AA6061 and evaluation of optimal process parameters using a Taguchi-based GRA. To check the significance of the processing variables on the output quality and quantity, ANOVA is used. A confirmation test was done at the selected optimal processing parameters combination to validate the experimental results.

Download Full-text

Phase transformation and layer evolution in molybdenum disilicide-silicon carbide nanolayered coatings

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170426 ◽

1994 ◽

Vol 52 ◽

pp. 538-539

Author(s):

H. Kung ◽

T. R. Jervis ◽

J.-P. Hirvonen ◽

M. Nastasi ◽

T. E. Mitchell ◽

...

Keyword(s):

Phase Transformation ◽

High Temperature ◽

Oxidation Resistance ◽

Elevated Temperatures ◽

Matrix Material ◽

Molybdenum Disilicide ◽

High Temperature Strength ◽

Cross Sectional ◽

Good Oxidation Resistance ◽

Structural Applications

MoSi2 is a potential matrix material for high temperature structural composites due to its high melting temperature and good oxidation resistance at elevated temperatures. The two major drawbacksfor structural applications are inadequate high temperature strength and poor low temperature ductility. The search for appropriate composite additions has been the focus of extensive investigations in recent years. The addition of SiC in a nanolayered configuration was shown to exhibit superior oxidation resistance and significant hardness increase through annealing at 500°C. One potential application of MoSi2- SiC multilayers is for high temperature coatings, where structural stability ofthe layering is of major concern. In this study, we have systematically investigated both the evolution of phases and the stability of layers by varying the heat treating conditions.Alternating layers of MoSi2 and SiC were synthesized by DC-magnetron and rf-diode sputtering respectively. Cross-sectional transmission electron microscopy (XTEM) was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: crystallization and phase transformation of MoSi2, crystallization of SiC, and spheroidization of the layer structures.

Download Full-text

UNS T20819

Alloy Digest ◽

10.31399/asm.ad.ts0496 ◽

1989 ◽

Vol 38 (2) ◽

Keyword(s):

Elevated Temperatures ◽

Hot Extrusion ◽

Heat Treating ◽

High Toughness ◽

Extrusion Dies ◽

Extrusion Die ◽

Steel Mills ◽

Temperature Performance ◽

Heat Checking ◽

Resistance To Heat

Abstract UNS T20819 is a hot-work tool and die steel that is characterized by excellent resistance to shock and abrasion at elevated temperatures. This steel provides relatively high toughness and outstanding resistance to heat checking and softening at elevated temperatures. Among its many applications are hot-punch tools, forging dies and inserts, brass extrusion dies, permanent molds for brass casting and hot-extrusion die inserts for steel. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-496. Producer or source: Tool steel mills.

Download Full-text

Analysis and optimization of hot extrusion process on strenx steel 900

Materials Today Proceedings ◽

10.1016/j.matpr.2021.04.453 ◽

2021 ◽

Author(s):

A. Damodar Reddy ◽

P.N. Karthikeyan ◽

S. Krishnaraj ◽

Adarsh Ajayan ◽

K. Sunil Kumar Reddy ◽

...

Keyword(s):

Hot Extrusion ◽

Extrusion Process

Download Full-text

Al Matrix Composites Reinforced by Ti and C Dedicated to Work at Elevated Temperature

Materials ◽

10.3390/ma14113114 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3114

Author(s):

Bartosz Hekner ◽

Jerzy Myalski ◽

Patryk Wrześniowski ◽

Tomasz Maciąg

Keyword(s):

Working Conditions ◽

Elevated Temperatures ◽

Aluminium Matrix ◽

Carbon Surface ◽

Matrix Composites ◽

Time Intervals ◽

Aluminium Matrix Composites ◽

Al Matrix Composites ◽

Microstructure Of The Material ◽

Al Matrix

In this paper, the applicability of aluminium matrix composites to high-temperature working conditions (not exceeding the Al melting point) was evaluated. The behaviour of Al-Ti-C composites at elevated temperatures was described based on microstructural and phase composition observations for composites heated at temperatures of 540 and 600 °C over differing time intervals from 2 to 72 h. The materials investigated were aluminium matrix composites (AMC) reinforced with a spatial carbon (C) structure covered by a titanium (Ti) layer. This layer protected the carbon surface against contact with the aluminium during processing, protection which was maintained for the material’s lifetime and ensured the required phase compositions of Al4C3 phase limitation and AlTi3 phase creation. It was also proved that heat treatment influenced not only phase compositions but also the microstructure of the material, and, as a consequence, the properties of the composite.

Download Full-text

Racemization in stepwise solid-phase peptide synthesis at elevated temperatures

Tetrahedron ◽

10.1016/j.tet.2004.03.070 ◽

2004 ◽

Vol 60 (21) ◽

pp. 4671-4681 ◽

Cited By ~ 31

Author(s):

Marcos P. Souza ◽

Marina F.M. Tavares ◽

M.Terêsa M. Miranda

Keyword(s):

Peptide Synthesis ◽

Elevated Temperatures ◽

Solid Phase ◽

Solid Phase Peptide Synthesis

Download Full-text

Experimental Investigation of Ti-6Al-4V with a Biaxial Tensile Test Setup at Elevated Temperature

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.622-623.273 ◽

2014 ◽

Vol 622-623 ◽

pp. 273-278 ◽

Cited By ~ 1

Author(s):

Marion Merklein ◽

Sebastian Suttner ◽

Adam Schaub

Keyword(s):

Elevated Temperature ◽

Elevated Temperatures ◽

Tensile Tests ◽

Advanced Materials ◽

Uniaxial Tensile ◽

Plastic Yielding ◽

Characterization Methods ◽

Specific Strength ◽

Biaxial Tensile ◽

Stress States

The requirement for products to reduce weight while maintaining strength is a major challenge to the development of new advanced materials. Especially in the field of human medicine or aviation and aeronautics new materials are needed to satisfy increasing demands. Therefore the titanium alloy Ti-6Al-4V with its high specific strength and an outstanding corrosion resistance is used for high and reliable performance in sheet metal forming processes as well as in medical applications. Due to a meaningful and accurate numerical process design and to improve the prediction accuracy of the numerical model, advanced material characterization methods are required. To expand the formability and to skillfully use the advantage of Ti-6Al-4V, forming processes are performed at elevated temperatures. Thus the investigation of plastic yielding at different stress states and at an elevated temperature of 400°C is presented in this paper. For this reason biaxial tensile tests with a cruciform shaped specimen are realized at 400°C in addition to uniaxial tensile tests. Moreover the beginning of plastic yielding is analyzed in the first quadrant of the stress space with regard to complex material modeling.

Download Full-text