Elevated Temperature Tensile Behavior of Rheo-Cast 7075-T6 Al Alloy Produced by GISS Technique

2014 ◽  
Vol 881-883 ◽  
pp. 1597-1600 ◽  
Author(s):  
Narissara Mahathaninwong ◽  
Sirikul Wisutmethangoon ◽  
Thawatchai Plookphol ◽  
Jessada Wannasin ◽  
Suchart Chantaramanee

Tensile properties of rheo-cast 7075-T6 Al alloy produced by Gas Induced Semi-Solid (GISS) technique was investigated as a function of temperatures from 25°C to 250 °C in order to assess the potent of high temperature applications. It was found that the ultimate tensile strength and yield strength of the alloy decreased steadily with increasing temperature. There was loss in strength of about 33% at 200°C and 46% at 250 °C comparing to the strength at room temperature. At T = 250 °C, the ultimate tensile strength and yield strength of the rheo-cast 7075-T6 Al alloy were higher than those of the wrought 7075-T651 Al alloy. Keyword: 7075 Al alloy; Gas Induced Semi Solid (GISS) technique; Elevated temperature tensile.

2007 ◽  
Vol 546-549 ◽  
pp. 305-310
Author(s):  
Bao Yi Yu ◽  
Yu Ying Li ◽  
Hong Wu Song ◽  
Xiao Guang Yuan ◽  
Zhen Liu

Microstructures and tensile properties of Mg-8Zn-4Al-xCax=0.6wt.%, 1.0wt.%, 1.3wt.%, named as alloy 1#, 2# and 3# , respectively)extruded magnesium alloy tube were studied at room and elevated temperature. The results show that Ca can increase tensile strength of the alloy at 150 and 200°C significantly. At the temperature of 200°C, alloy 3# achieved optimal tensile properties, of which the ultimate tensile strength, the yield strength and the elongation were 165.8MPa, 108.7Mpa and 41.5% respectively. Compared with the properties of as cast ZAC8506 Magnesium alloy, it is shown that the tensile properties of alloy 3# are much higher than that of ZAC8506 at both room temperature and 150°C. Alloy 3# also gets better tensile performance than AZ91D extruded tube produced in the same way at the temperature of 200°C Mg2Al3 and Ca2Mg5Zn13 phases are found in the microstructure which should contribute to the higher performance of alloy 3# at elevated temperature


1973 ◽  
Vol 95 (1) ◽  
pp. 235-242 ◽  
Author(s):  
R. A. Swift ◽  
J. A. Gulya

A study of the effects of normalizing and austenitizing on the mechanical properties of Mn-Mo and Mn-Mo-Ni steels is presented. It is shown that the quenched and tempered condition has superior notch toughness, elevated temperature tensile properties, and creep ductility than the normalized and tempered condition. The basis of comparison used for strength is the percentage of the room temperature strength. The creep strength and rupture resistance of the normalized and tempered condition are better than those of the quenched and tempered condition. Also, a comparison of the properties of the steels is made to evaluate the effects of a 0.5 percent Ni addition. While it improves hardenability, Ni tends to impair the elevated temperature creep strength and rupture resistance. Significant effects of Ni are seen on the elevated temperature tensile properties. The loss in ultimate tensile strength with increasing temperature is greater for the Ni modified grade than for the unmodified Mn-Mo. In the quenched and tempered condition, both yield strength and ultimate tensile strength are less affected by temperature when no Ni is added.


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.


Author(s):  
B. F. Luan ◽  
L. Q. Yang ◽  
T. G. Wei ◽  
K. L. Murty ◽  
C. S. Long ◽  
...  

To investigate the effects of Mo and Bi on mechanical properties of a Zr-Fe-Cr alloy at room temperature, seven Zr-Fe-Cr-Mo-Bi alloys with different compositions were designed. They were subjected to a series of rolling processes and heat treatments, and then sampled to measure mechanical properties by hardness and tensile test and to characterize microstructures by scanning electron microscope (SEM) and electron channel contrast (ECC) technique. Results indicated that among them two types of Zr-Fe-Cr-Mo-Bi alloys achieve the designed goals on mechanical properties and have the following advantages: (i) the hardness of the alloys, up to 334HV after annealing, is 40% higher than traditional Zr-4. (ii) The yield strength (YS) and ultimate tensile strength (UTS) of the alloys are 526 MP a and 889 MP a after hot rolling and annealing, markedly higher than the traditional Zr alloy. (iii) Good plasticity of the new Zr-Fe-Cr-Mo-Bi alloy is obtained with about 40% elongation, which is greatly higher than the Zr-Fe-Cr-Mo alloy thanks to the addition of Bi offsetting the disadvantage of addition Mo. Furthermore, according to observations of the microstructure observation, the reasons of the effect of the Mo and Bi elements on the mechanical performance of Zr-Fe-Cr alloy were studied and discussed.


2010 ◽  
Vol 129-131 ◽  
pp. 65-69 ◽  
Author(s):  
Kai Huai Yang ◽  
Wen Zhe Chen

Three groups of commercial 1060 Al alloy sheets were subjected to constrained groove pressing (CGP) at room temperature using parallel CGP, 180° cross CGP and 90° cross CGP, respectively. Tensile properties and fracture modes of as-annealed and CGPed samples were investigated. The ultimate tensile strength (UTS) of 1060 Al increases significantly after CGP, while the elongation decreases. But they are strongly dependence on the number of CGP passes and the pressing modes. The UTS and elongation of the samples processed by 90° cross CGP are best, consequently, the static toughness of the 90° cross CGPed samples is enhanced. Besides, all CGPed specimens failed in a ductile manner. With increasing the number of CGP pass, the amount of small dimples increases, and the dimples become shallow and more uniform.


2013 ◽  
Vol 668 ◽  
pp. 3-8 ◽  
Author(s):  
Jian Rong Sun ◽  
Chang Sheng Li ◽  
Hua Tang ◽  
Zhi Cheng Guo ◽  
Jin Ying Zi Liu

The composites of Ni-W-Cr-Fe-Cu-MoS2-Graphite with nano-MoS2 were prepared by powder metallurgy. Its tribological properties were investigated using the UTM-2 Nano+Micro Tribometer from room temperature to 600°C. The effects of amount of MoS2 and Ni-W-Cr prealloy powder, load, and temperature on the tribological properties were investigated and discussed. The results indicated that the addition of 43~45wt.% Ni-W-Cr prealloy powder had a strengthening effect on the hardness, anti-press and tensile strength. The tensile strength of the composite decreases with the addition of Nano-MoS2 and graphite, and the friction coefficient decrease with increase of the additives over the wide temperature range of 25°C∼600°C. The friction coefficients and wear rates of the composites reach the optimization value at 2.5wt.% MoS2,While its wear rates increase with the increasing temperature and load.


In the present study, Response Surface Methodology (RSM) is implemented to determine optimum process variables of TIG welding of Incoly-800HT sheets. Voltage, Welding current and speed of welding are considered as factors. Ultimate tensile strength at room temperature, yield strength at room temperature, ultimate tensile strength at 7500C, yield strength at 7500C and toughness are considered as responses. The Design of Experiment based on central composite response surface design, experimenting is formulated using the Design Expert 12 software. Grey Relational Analysis (GRA) carried on the responses and grey relational coefficients are calculated. The grey relational coefficients are subjected to Principal Component Analysis (PCA) using PAST 3.26 software that transforms the five responses into a single response. The optimization of parameters is carried by Response Surface Methodology and contribution by each input parameter is estimated by ANOVA (Analysis of Variance).


Materials ◽  
2003 ◽  
Author(s):  
D. M. Pai ◽  
S. N. Yarmolenko ◽  
E. Freeman ◽  
L. P. Zawada

The tensile behavior of Nextel 720 fibers at elevated temperature was compared with room temperature results for both bare and monazite-coated fibers. While coated and uncoated fibers have nearly identical tensile strengths and Weibull moduli at room temperature, differences in response were seen at elevated temperature. Coated fibers tested at 1200°C were found to have a 40% drop in strength. Uncoated fibers at high temperature exhibited 55% less strength than at room temperature. However, the tensile strength distribution for uncoated fibers tested at high temperature exhibited two distinct populations, indicating two different failure mechanisms. One population showed a 50% drop while the other showed a 64% drop. The coating was thus found to have a protective effect in terms of short-duration high-temperature exposure. Further, the effect of soaking on strength was investigated by thermally soaking coated and uncoated fibers in air at 1200°C for 100 hours prior to tensile testing at elevated temperature. In this case, the long duration of thermal exposure appeared to eliminate the beneficial effects of the coating. Soaked fibers, both coated and uncoated, were found to have nearly identical strengths at 1200°C—a reduction of about 60%.


2008 ◽  
Vol 141-143 ◽  
pp. 779-784 ◽  
Author(s):  
Hai Ping Cao ◽  
Olof Granath ◽  
Magnus Wessen

The RHEOMETALTM process is a commercially used semi-solid process for production of high integrity cast components. The process differs from most other semi-solid casting processes in that temperature control is not necessary during processing and large amount of slurry with required solid fraction can be quickly produced. The simplicity of this process has led to a large commercial interest during the last year. This work is based on an investigation regarding the variation of as-cast mechanical properties for secondary Al-Si based alloys (~2.5 % Cu) with a Si content varying from 4.55 to 8.90 % using the RHEOMETALTM process. The purpose was to find the most suitable Al-Si alloy for rheocasting, in comparison with the common HPDC-alloy A380 (EN-AC46000). It was found that lower Si containing alloys exhibited better elongation but slightly lower yield strength. The alloy containing 5.39 wt% Si showed the highest ultimate tensile strength in this investigation. The lower Si containing alloys also demonstrated better feedability in the rheocasting process, which is contrary to what normally is found for normal liquid casting processes. Based on the results in this investigation it is recommended to use an alloy containing about 5-7 wt% Si for rheocasting purposes.


2012 ◽  
Vol 629 ◽  
pp. 198-202 ◽  
Author(s):  
Ping Yang ◽  
Kai Huai Yang

Three groups of commercial 1050 Al alloy were subjected to equal channel angular pressing (ECAP) at room temperature using route A, route C and route Bc, respectively. Mechanical properties and fracture modes of as-annealed and ECAPed samples were investigated. The microhardness of 1050 Al fabricated by ECAP increases by a factor of about 1.5 compared to the as-annealed state. The ultimate tensile strength (UTS) increases significantly after ECAP, while the elongation decreases. But they are strongly dependence on the number of ECAP passes and the pressing route. The UTS and elongation of the samples processed by route Bc are best, consequently, the static toughness U of the samples is enhanced. Besides, all specimens subjected to ECAP deformation failed in a ductile manner.


Sign in / Sign up

Export Citation Format

Share Document