scholarly journals Understanding Room Temperature Deformation of High-Strength Titanium Alloys

2021 ◽  
Vol 27 (S1) ◽  
pp. 28-29
Author(s):  
John Foltz ◽  
Shaolou Wei ◽  
Luis Ruiz-Aparicio ◽  
Andy Martinez ◽  
C. Cem Tasan
Keyword(s):  
Titanium Alloys ◽  
Room Temperature ◽  
High Strength ◽  
Temperature Deformation

Experimental and Modeling Studies on the Stress Relaxation Behaviour of Ti-6Al-4V Alloy

2021 ◽  
Author(s):  
Kali Prasad ◽  
Krishnaswamy Hariharan ◽  
Dilip K. Banerjee
Keyword(s):  
Stress Relaxation ◽  
Titanium Alloys ◽  
Room Temperature ◽  
Hold Time ◽  
High Strength ◽  
Uniaxial Tensile ◽  
Time Data ◽  
Transient Stress ◽  
Ti Alloys ◽  
Strain And Strain Rate

Abstract The transient mechanical behavior of materials during stress relaxation has evoked interest in manufacturing applications because of the effect of stress relaxation on formability enhancement. However, most of the previous studies have focused on advanced high strength steels and aluminum alloys. Limited transient stress relaxation studies have been conducted on titanium alloys in order to understand the influence of stress relaxation on forming behavior. Titanium alloys are widely used in aerospace components because of their high strength to weight ratios and excellent fatigue strengths. However, room temperature formability of Ti alloys is an important concern, which restricts their widespread use in various applications. To address these challenges, the present study is aimed to understand the role of transient stress relaxation on formability of Ti alloys. Toward this end, stress relaxation of a dual phase titanium alloy (Ti-6Al-4V) has been investigated experimentally. Stress relaxation tests were performed by interrupting uniaxial tensile tests in the uniform deformation regime for a pre-defined strain and hold time after which tests were continued monotonically until fracture. Single step, room temperature stress relaxation experiments were performed systematically to study the effect of hold time, pre-strain, and strain rate on mechanical properties. The stress relaxation phenomenon was found to contribute positively to the ductility improvement. The mechanisms responsible for enhancing the formability are discussed. The experimentally obtained stress vs. time data were analyzed using a advanced constitutive model for stress relaxation available in literature.

Mechanical Characteristics of Zn-22% Al and Al-3% Mg Alloys Processed to High Strains by ECAP

2010 ◽  
Vol 667-669 ◽  
pp. 695-700
Author(s):  
Praveen Kumar ◽  
Terence G. Langdon
Keyword(s):  
Melting Temperature ◽  
Room Temperature ◽  
High Strength ◽  
Processing Technique ◽  
Mg Alloys ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Processing Route ◽  
Strain Rates ◽  
High Ductility

A processing route enhancing the strength of a metallic material usually leads to a decrease in the ductility. Therefore, a mechanical processing technique improving the ductility as well as the strength of a structural material is of significant importance. The present study employs equal-channel angular pressing to impart high strains up to ~24 and ~8, via route BC, in Zn-22% Al and Al-3% Mg alloys, respectively. Tensile specimens, machined from the central region of the processed materials, were tested at room temperature between strain rates of 10-3 and 1 s-1. The Zn-22% Al did not show the presence of a critical strain above which high ductility-high strength could be simultaneously achieved at any strain rate. However, Al-3% Mg processed through 8 passes of ECAP showed a transition to a high strength-high ductility region at high strain rates. The occurrence of high strength and high ductility in Al-3% Mg after processing to very high strains is probably due to the transition from the heavily deformed and heterogeneous microstructure present at the lower strains when processing by ECAP to the more homogeneous structures that develop after larger numbers of passes in ECAP. The absence of a transition strain in Zn-22% Al is attributed to its low melting temperature so that even at room temperature (~0.54Tm where Tm is the melting temperature) it shows diffusion-controlled high temperature deformation behavior.

ALUMINUM 713.0

Alloy Digest ◽  
1985 ◽  
Vol 34 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Room Temperature ◽  
High Strength ◽  
Heat Treating ◽  
Good Combination ◽  
Casting Alloy ◽  
Silicon Alloys ◽  
Aluminum Silicon Alloys ◽  
Permanent Mold Castings ◽  
Aluminum Base

Abstract ALUMINUM 713.0 is an aluminum-base casting alloy that ages at room temperature to provide high-strength sand and permanent-mold castings. It has a good combination of mechanical properties and its corrosion resistance is equivalent to that of the aluminum-silicon alloys. It is dimensionally stable. Among its many uses are housings, machinery parts, fittings, lever arms and brackets. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-263. Producer or source: Various aluminum companies.

scholarly journals Room-temperature deformation of single crystals of ZrB2 and TiB2 with the hexagonal AlB2 structure investigated by micropillar compression

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhenghao Chen ◽  
Bhaskar Paul ◽  
Sanjib Majumdar ◽  
Norihiko L. Okamoto ◽  
Kyosuke Kishida ◽  
...  
Keyword(s):  
Single Crystals ◽  
Plastic Flow ◽  
Room Temperature ◽  
Resolve Shear Stress ◽  
Temperature Deformation ◽  
Slip Systems ◽  
Compression Tests ◽  
Plastic Deformation Behavior ◽  
Bulk Single Crystals ◽  
Micropillar Compression

AbstractThe plastic deformation behavior of single crystals of two transition-metal diborides, ZrB2 and TiB2 with the AlB2 structure has been investigated at room temperature as a function of crystal orientation and specimen size by micropillar compression tests. Although plastic flow is not observed at all for their bulk single crystals at room temperature, plastic flow is successfully observed at room temperature by the operation of slip on {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 3> in ZrB2 and by the operation of slip on {1$${\bar{1}}$$ 1 ¯ 00}<0001> and {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 0> in TiB2. Critical resolve shear stress values at room temperature are very high, exceeding 1 GPa for all observed slip systems; 3.01 GPa for {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 3> slip in ZrB2 and 1.72 GPa and 5.17 GPa, respectively for {1$${\bar{1}}$$ 1 ¯ 00}<0001> and {1$${\bar{1}}$$ 1 ¯ 00}<11$${\bar{2}}$$ 2 ¯ 0> slip in TiB2. The identified operative slip systems and their CRSS values are discussed in comparison with those identified in the corresponding bulk single crystals at high temperatures and those inferred from micro-hardness anisotropy in the early studies.

scholarly journals Modification of Mechanical Properties of High-Strength Titanium Alloys VT23 and VT23M Due to Impact-Oscillatory Loading

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 80 ◽  
Author(s):  
Mykola Chausov ◽  
Janette Brezinová ◽  
Andrii Pylypenko ◽  
Pavlo Maruschak ◽  
Liudmyla Titova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Titanium Alloys ◽  
High Strength ◽  
The Self ◽  
Self Organization ◽  
Two Phase ◽  
Rolled Metal ◽  
Technological Method ◽  
Equilibrium Processes ◽  
Production Conditions

A simple technological method is proposed and tested experimentally, which allows for the improvement of mechanical properties in sheet two-phase high-strength titanium alloys VT23 and VT23M on the finished product (rolled metal), due to impact-oscillatory loading. Under impact-oscillatory loading and dynamic non-equilibrium processes (DNP) are realized in titanium alloys, leading to the self-organization of the structure. As a result, the mechanical properties of titanium alloys vary significantly with subsequent loading after the realization of DNP. In this study, the test modes are found, which can be used in the production conditions.

scholarly journals Design of Low-Cost and High-Strength Titanium Alloys Using Pseudo-Spinodal Mechanism through Diffusion Couple Technology and CALPHAD

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2910
Author(s):  
Chaoyi Ding ◽  
Chun Liu ◽  
Ligang Zhang ◽  
Di Wu ◽  
Libin Liu
Keyword(s):  
Diffusion Couple ◽  
Titanium Alloys ◽  
High Throughput ◽  
Volume Fraction ◽  
Raw Materials ◽  
Low Cost ◽  
High Strength ◽  
High Yield ◽  
Α Phase ◽  
Cr System

The high cost of development and raw materials have been obstacles to the widespread use of titanium alloys. In the present study, the high-throughput experimental method of diffusion couple combined with CALPHAD calculation was used to design and prepare the low-cost and high-strength Ti-Al-Cr system titanium alloy. The results showed that ultra-fine α phase was obtained in Ti-6Al-10.9Cr alloy designed through the pseudo-spinodal mechanism, and it has a high yield strength of 1437 ± 7 MPa. Furthermore, application of the 3D strength model of Ti-6Al-xCr alloy showed that the strength of the alloy depended on the volume fraction and thickness of the α phase. The large number of α/β interfaces produced by ultra-fine α phase greatly improved the strength of the alloy but limited its ductility. Thus, we have demonstrated that the pseudo-spinodal mechanism combined with high-throughput diffusion couple technology and CALPHAD was an efficient method to design low-cost and high-strength titanium alloys.

scholarly journals The influence of high-temperature oxidation on the phase distribution of metal substrate in duplex stainless steel

2021 ◽  
Author(s):  
Minami Matsumoto ◽  
Ken Kimura ◽  
Natsuko Sugiura
Keyword(s):  
Stainless Steels ◽  
Room Temperature ◽  
Phase Distribution ◽  
High Strength ◽  
Metal Substrate ◽  
Temperature Oxidation ◽  
Good Corrosion Resistance ◽  
Mn Oxide ◽  
Typical Type ◽  
Compositional Changes

AbstractDuplex stainless steels (DSSs), which consist of ferrite and austenite phases, are widely used owing to their high strength and good corrosion resistance. However, the oxidation behavior of DSSs is extremely complicated because they have dual phases. In this study, changes in the scale and the metal substrate during oxidation were investigated. UNS S32101 (Fe-21.5%Cr–5%Mn–1.5%Ni–0.3%Mo–0.22%N), which is a typical type of DSS, was annealed at 1473 K for up to 36 ks in air. The microstructure of UNS S32101 consisted of austenite/ferrite phases, the ratio of which was 50:50 at room temperature. After oxidation, Cr, Mn-oxide formed predominantly. The metal substrate beneath the scale changed mostly to ferrite. In the same region, depletion of Mn and N concentrations resulted. The decrease in Mn was due to the formation of Cr, Mn-oxide. In addition, it was revealed that N content of the metal substrate decreased due to the formation of N2 gas along with the depletion of Mn. It was assumed that the decrease in Mn and N, which are austenite-stabilized elements, led to an increase in ferrite in the depletion area of Mn and N. From this result, it was expected that the compositional changes in the Mn/N depletion area were caused by the oxidation of steel.

Study of the Key Issues of Friction Stir Welding of Titanium Alloy

2010 ◽  
Vol 638-642 ◽  
pp. 1185-1190 ◽  
Author(s):  
Hui Jie Liu ◽  
Li Zhou ◽  
Yong Xian Huang ◽  
Qi Wei Liu
Keyword(s):  
Titanium Alloy ◽  
Friction Stir Welding ◽  
Melting Point ◽  
Titanium Alloys ◽  
Welding Process ◽  
High Strength ◽  
Liquid Cooling ◽  
Friction Stir ◽  
Key Issues ◽  
Aluminum And Magnesium Alloys

As a new solid-state welding process, friction stir welding (FSW) has been successfully used for joining low melting point materials such as aluminum and magnesium alloys, but the FSW of high melting point materials such as steels and titanium alloys is still difficult to carry out because of their strict requirements for the FSW tool. Especially for the FSW of titanium alloys, some key technological issues need to solve further. In order to accomplish the FSW of titanium alloys, a specially designed tool system was made. The system was composed of W-Re pin tool, liquid cooling holder and shielding gas shroud. Prior to FSW, the Ti-6Al-4V alloy plates were thermo-hydrogen processed to reduce the deformation resistance and tool wear during the FSW. Based on this, the thermo-hydrogen processed Ti-6Al-4V alloy with different hydrogen content was friction stir welded, and the microstructural characterizations and mechanical properties of the joints were studied. Experimental results showed that the designed tool system can fulfill the requirements of the FSW of titanium alloys, and excellent weld formation and high-strength joint have been obtained from the titanium alloy plates.

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