Effects of Cooling Rate on the Microstructure and Room Temperature Tensile Properties of Orthorhombic Ti-22Al-21Nb-1Ta-1W Alloy

2005 ◽  
Vol 475-479 ◽  
pp. 817-820
Author(s):  
Dong Luo ◽  
Yu You Cui ◽  
Rui Yang

In order to improve high temperature mechanical properties of Ti2AlNb based alloys, alloying with a combination of Ta and W was studied in the on-going work. The effects of cooling rate after solution heat treatment on the room temperature mechanical properties have been reported in this paper. All samples were solid solution treated at near β transus temperature, cooled at different cooling rates, and then aged at subtransus temperature. Experimental results showed that, with increasing cooling rate, room temperature yield strength decreased sharply to a minimum value, and then increased. Change of elongation exhibits a trend opposite to yield strength. Microstructure of the alloy varied from near lamellar to lamellar plus Widmanstätten, and then to full Widmanstätten structure with the increase of cooling rate, and the faster the cooling rate, the finer the laths of the O phase. The samples with near lamellar microstructure obtained at the cooling rate of 6oC/min possess the best ductility but relatively low yield strength.

2007 ◽  
Vol 561-565 ◽  
pp. 647-650 ◽  
Author(s):  
Syed Humail Islam ◽  
M. Tufail ◽  
Xuan Hui Qu

The high temperature mechanical properties of dual phase heavy metal of 95W-3.5Ni-1.5Fe alloy were investigated in tension. The specimens were prepared by liquid phase sintering. Yield strength decreased and ductility increased as the testing temperature was increased to 300°C, reached a plateau at between 300 and 500°C and then decreased considerably. The fracture modes of alloys when deformed at room temperature were a mixture of intergranular fracture and transgranular cleavage. As the temperature was increased, the percentage of intergranular cleavage increased, although transgranular fracture also remained. At higher temperatures, substantial reduction in ductility and in yield strength was a result of loss of bonding strength between tungsten grains and matrix phase.


2012 ◽  
Vol 482-484 ◽  
pp. 1530-1533
Author(s):  
Ming Li Huang ◽  
Hua Ying Li ◽  
Hua Ding

In the present work, mechanical properties and microstructures of hot-rolled and solution-treated Fe-26Mn-6Al-1C steel (6Al steel) were investigated. Tensile tests were carried out at room temperature. The samples were characterized by using XRD, OM, SEM and TEM. The results suggested that the microstructure of the hot rolled 6Al steel was fully austenitic. After solution treatment and deformation, the microstructure was still single austenite. With the increase of the solution treatment temperatures, the strength decreased and the elongation increased. After solution treated at 1100°C for 1h, the yield strength, ultimate tensile strength and elongation were 378MPa, 756MPa and 57%.


2013 ◽  
Vol 747-748 ◽  
pp. 470-477
Author(s):  
Rui Dong Liu ◽  
Xu Guang Dong ◽  
Fu Jun Wei ◽  
Yuan Sheng Yang

The effects of minor Al and Ce on the microstructures, room-temperature and high-temperature mechanical properties of as-cast Mg-6Zn magnesium alloys were investigated. With the Al addition into Mg-6Zn alloy, the coarse eutectic Mg51Zn20phases were refined and distributed discontinuously. After adding 0.5wt.% Ce into Mg-6Zn-1Al alloy, a new needle-like Al2CeZn2phase was observed. Meanwhile, the volume fraction of Mg51Zn20phase decreased and the semi-continuous Mg51Zn20phase became discontinuous globular morphology. It has been observed that the addition of Ce element coarsens the grains, and 1wt.% Al addition enhanced the yield strength and ultimate strength from 86.35MPa, 229MPa to 90.7MPa, 238MPa, respectively. Moreover, the Ce addition can significantly increase the high-temperature mechanical properties of cast Mg-6Zn-1Al alloy.


Alloy Digest ◽  
1975 ◽  
Vol 24 (9) ◽  

Abstract BERYLCO NICKEL ALLOY 440 is an age-hardenable nickel-beryllium-titanium alloy that offers high strength, excellent spring properties outstanding formability, good high-temperature mechanical properties, and resistance to corrosion and fatigue. Complex shapes can be produced in the solution-treated (soft) condition and then aged to a minimum tensile strength of 215,500 psi. It is used for mechanical and electrical/electronic components in the temperature range -320 to 800 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-94. Producer or source: Kawecki Berylco Industries Inc.. Originally published September 1964, revised September 1975.


Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.


2012 ◽  
Vol 602-604 ◽  
pp. 627-630 ◽  
Author(s):  
Kyu Sik Kim ◽  
Kee Ahn Lee ◽  
Jong Ha Kim ◽  
Si Woo Park ◽  
Kyu Sang Cho

Inconel 713C alloy was tried to manufacture by using MIM(Metal Injection Molding) process. The high-temperature mechanical properties of MIMed Inconel 713C were also investigated. Processing defects such as pores and binders could be observed near the surface. Tensile tests were conducted from room temperature to 900°C. The result of tensile tests showed that this alloy had similar or somewhat higher strengths (YS: 734 MPa, UTS: 968 MPa, elongation: 7.16 % at room temperature) from RT to 700°C than those of conventional Inconel 713C alloys. Above 800°C, however, ultimate tensile strength decreased rapidly with increasing temperature (lower than casted Inconel 713C). Based on the observation of fractography, initial crack was found to have started near the surface defects and propagated rapidly. The superior mechanical properties of MIMed Inconel 713C could be obtained by optimizing the MIM process parameters.


2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940052
Author(s):  
P. Deng ◽  
X. C. Wang ◽  
F. Zhang ◽  
X. M. Qin ◽  
P. Gao ◽  
...  

The mechanical-annealing referred in this work is also named pre-strain, which is widely investigated in TRIP steel, stainless steel, magnesium alloy and aluminum alloy. In this case, we used preloading to input energy into a bulk metallic glass (BMG) to observe the changes in the structure and mechanical properties. We selected Zr[Formula: see text]Co[Formula: see text]Al[Formula: see text] BMG as a model material owning to its outstanding glass forming ability and excellent mechanical properties. The samples were kept at a constant pressure of 1900, 1700 and 1500 MPa (below the yield strength) for 40, 55 and 70 h. The study found out that the density of those samples increased after being pre-loaded. Then, the samples underwent aging treatment at room-temperature for more than 30 days after unloading. After re-compressing the samples, the results show that the yield strength and fracture strength of the samples decreased, and the amplitude of the serrated plastic flow increased during the plastic stage. Our finding might have some implications for understanding the plastic deformation of BMGs.


2016 ◽  
Vol 849 ◽  
pp. 570-579
Author(s):  
Qiang Huang ◽  
Jin Xia Song ◽  
Qing Li ◽  
Wei Peng Ren ◽  
Xin Guang Guan ◽  
...  

The microstructures and mechanical properties of superalloy K465 under different heat treatment, including as as-cast, solution treatment and aging, were investigated. The results showed that γ' precipitates in as-cast condition exhibited two kinds of morphologies of fine regular cuboidal shape at dendritic arm and coarse irregular form in interdendritic region. MC carbides decomposed into M6C carbides partly after 1210°C/4h solution treatment. The high temperature stress-rupture life can be improved obviously with the increasing cooling rate. When cooling rate was lower than 70°C/min, the room temperature tensile elongation increased with cooling rate increasing. When cooling rate was higher than 90°C/min the room temperature tensile elongation decreased with cooling rate increasing. The proper cooling rate of 70oC/min~90oC/min is advantageous for the achievement of excellent comprehensive properties. When aging treatments continued the regularization of γ' resulted in the improvement of stress-rupture life and the reduction of tensile elongation. The mechanical property gap between the solution treatment and aging can be decreased with increasing cooling rate.


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