Effects of aging on microstructure evolution and mechanical properties of high-temperature Zn-4Al-3Mg solder

2014 ◽  
Vol 26 (4) ◽  
pp. 203-213 ◽  
Author(s):  
Huan Wang ◽  
Yongchang Liu ◽  
Huixia Gao ◽  
Zhiming Gao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Aging Treatment ◽  
Tensile Tests ◽  
Softening Effect ◽  
Cooling Rates ◽  
Content Type ◽  
X Ray ◽  
Microstructural Alterations ◽  
Effects Of Aging

Purpose – This paper aims to investigate the transformations during aging at 200°C for different periods on microstructure and mechanical properties of high-temperature Zn-4Al-3Mg solders. Design/methodology/approach – The solder was melted in a resistance furnace, and different cooling rates were obtained by changing the cooling medium. Subsequently, all the specimens were aged at 200°C for 20 h and 50 h. A scanning electron microscope equipped with an energy dispersive X-ray detector and X-ray diffraction were used for the observation of microstructures and the determination of phase composition. Tensile tests and Rockwell hardness tests were also performed. Findings – After aging, Zn atoms precipitated from the supersaturated α-Al and the (α-Al + η-Zn)eutectoid phase with the original fine lamellar structure coarsened and spheroidized to minimize the system energy. Among these solders, the furnace-cooled alloys exhibited the highest thermal stability, largely retaining their original morphology after aging, whereas the collapse and spheroidization of the η-Zn phase and the coarsening of the η-Zn dendrites took place in the air-cooled and water-cooled samples, respectively. Furthermore, a decrease in tensile strength during aging was attributed to the thermal softening effect. The variation of macro-hardness was mainly associated with the microstructural alterations in terms of quantity, morphology and distribution of soft η-Zn phase and hard intermetallic compounds induced by the aging treatment. Originality/value – The structural stability of eutectic Zn-4Al-3Mg solders solidified at different cooling rates and the effect of aging on mechanical properties were investigated.

Effect of Aging Treatment on High Temperature Strength of Nb Added Ferritic Stainless Steels

2005 ◽  
Vol 475-479 ◽  
pp. 191-194 ◽  
Author(s):  
Jae Cheon Ahn ◽  
Gyu Man Sim ◽  
Kyung Sub Lee
Keyword(s):  
High Temperature ◽  
Stainless Steels ◽  
Early Stage ◽  
Aging Treatment ◽  
Tensile Tests ◽  
The Other ◽  
High Temperature Strength ◽  
Ferritic Stainless Steels ◽  
Automotive Parts ◽  
Effects Of Aging

Effects of aging treatment on high temperature strength of Nb added ferritic stainless steels for automotive parts were investigated. Hot tensile tests were carried out at 700 °C after the aging at 700 °C for different aging times using Gleeble 1500. High temperature strength of all steels decreased as the aging time increased. In Nb free steels, the reduction in high temperature strength is mainly due to grain growth. On the other hand, in Nb added steels, the reduction in high temperature strength occurred by Nb precipitation. It was observed that Fe2Nb (Laves phase), Nb(C,N) and Fe3Nb3C were precipitated out during the aging at 700 °C in Nb added steels. The coarsening rate of Fe2Nb was higher than that of Nb(C,N). Fine Fe2Nb precipitates formed during at the early stage of aging contributed to high temperature strength in 0.01C-0.38Nb steel. However, coarse Fe2Nb particles formed during the aging were very detrimental to high temperature strength. The coarsening of Fe2Nb was relatively retarded by adding Mo.

Microstructural and Mechanical Properties of Cu-based Alloy Manufactured by Self-Propagating High-Temperature Synthesis Method

2017 ◽  
Vol 33 (3-4) ◽  
pp. 121
Author(s):  
Y. Amiour ◽  
K. Zemmour ◽  
D. Vrel
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Brinell Hardness ◽  
Synthesis Method ◽  
Tensile Tests ◽  
The Self ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
X Ray ◽  
High Temperature Synthesis

<p>Microstructure and properties of Cu<sub>1-x</sub>Zn<sub>1-y</sub>Al<sub>1-z</sub> ranging through (0.29 &lt;X&lt; 0.30; 0.74 &lt;Y&lt; 0.75; and 0.83 &lt;Z&lt; 0.96) alloys obtained by the Self- propagating High-temperature Synthesis (SHS) were examined. The microstructural and mechanical properties were examined, respectively by X-ray diffraction, tensile tests and Brinell hardness. The obtained results showed that the modification of composition lead to the formation of new phases. Therefore, this microstructure affects strongly the mechanical properties of the selected samples. In this study, we will also highlight the SHS technology and prove that it can alternate the conventional methods regarding the development of a Shape Memory Alloys (SMAs).</p><p> </p>

Effects of the Aging Time and Temperature on the Microstructures and Mechanical Properties of 6082 Aluminum Alloy Extrusions

2013 ◽  
Vol 652-654 ◽  
pp. 1035-1042
Author(s):  
Tao Wu ◽  
Xian Fei Ding ◽  
Jing Sun ◽  
Wei Dong Zhang ◽  
Dong Bai Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Aging Time ◽  
Tensile Elongation ◽  
Aging Treatment ◽  
Longitudinal Direction ◽  
Tensile Tests ◽  
Main Task ◽  
6082 Aluminum Alloy ◽  
Effects Of Aging

The main task of this work was to study the effects of aging time and aging temperature on the microstructure and mechanical properties of 6082 aluminum alloy extrusions. Artificial aging was performed on the alloy extrusions at the temperatures of 150, 175 and 200 °C for the aging times of 4, 8 and 12 h. The microstructure evolution of the aluminum alloy extrusions with increase of the aging time and temperature was investigated by Field Emission Scanning Electron Microscope (FESEM). For the purpose of how the aging process affected the mechanical properties, tensile tests were performed. The results showed that the optimum aging treatment was 175 °C/4 h. Under this condition, the tensile strength (Rm) and the yield strength (Rp) in the longitudinal direction of the extrusions reached the maximum value more than 350MPa and 320MPa, respectively, and the tensile elongation (A) was more than 15%.

scholarly journals Mechanical Properties of Spruce Wood Extracted from GLT Beams Loaded by Fire

2021 ◽  
Vol 13 (10) ◽  
pp. 5494
Author(s):  
Lucie Kucíková ◽  
Michal Šejnoha ◽  
Tomáš Janda ◽  
Jan Sýkora ◽  
Pavel Padevět ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Cross Section ◽  
Negative Impact ◽  
Tensile Tests ◽  
Thermal Recovery ◽  
Bending Test ◽  
Small Scale ◽  
Spruce Wood ◽  
The Impact

Heating wood to high temperature changes either temporarily or permanently its physical properties. This issue is addressed in the present contribution by examining the effect of high temperature on residual mechanical properties of spruce wood, grounding on the results of full-scale fire tests performed on GLT beams. Given these tests, a computational model was developed to provide through-thickness temperature profiles allowing for the estimation of a charring depth on the one hand and on the other hand assigning a particular temperature to each specimen used subsequently in small-scale tensile tests. The measured Young’s moduli and tensile strengths were accompanied by the results from three-point bending test carried out on two groups of beams exposed to fire of a variable duration and differing in the width of the cross-section, b=100 mm (Group 1) and b=160 mm (Group 2). As expected, increasing the fire duration and reducing the initial beam cross-section reduces the residual bending strength. A negative impact of high temperature on residual strength has also been observed from simple tensile tests, although limited to a very narrow layer adjacent to the charring front not even exceeding a typically adopted value of the zero-strength layer d0=7 mm. On the contrary, the impact on stiffness is relatively mild supporting the thermal recovery property of wood.

Influence of High Temperature Annealing on Microstructure Evolution of Ni-24Fe-14Cr-8Mo Superalloy

2021 ◽  
Vol 904 ◽  
pp. 117-123
Author(s):  
Yi Cui ◽  
Yun Fei Zhang ◽  
Yan Guang Han ◽  
Da Lv
Keyword(s):  
High Temperature ◽  
Microstructure Evolution ◽  
Testing Machine ◽  
Aging Treatment ◽  
Growth Patterns ◽  
High Temperature Annealing ◽  
Rockwell Hardness ◽  
Hardness Testing ◽  
X Ray Diffraction ◽  
X Ray

The effect of high temperature annealing on microstructure evolution of Ni-24Fe-14Cr-8Mo alloy was investigated through Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Rockwell Hardness Testing Machine. Three kinds of grain growth patterns were found at different annealing temperatures due to carbides precipitation and dissolution. After a combination of high temperature annealing and aging treatment, the hardness versus time curves performed a parabolic pattern. The highest hardness was achieved under 1070°C/60 minutes treatment, and the desirable annealing time should be 60 minutes to 90 minutes.

Mechanical and microstructural behavior of concrete containing marble and nano silica

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gaurav Sancheti ◽  
Vikram Singh Kashyap ◽  
Jitendra Singh Yadav
Keyword(s):  
Mechanical Properties ◽  
Nano Silica ◽  
Microstructural Characteristics ◽  
Content Type ◽  
X Ray ◽  
Static Modulus ◽  
Marble Dust ◽  
Microstructural Behavior ◽  
Static Modulus Of Elasticity ◽  
Concrete Matrix

Purpose The purpose of this study is to perform comprehensive investigation to assess the mechanical properties of nano-modified ternary cement concrete blend. Nano silica (NS) (1%, 2% and 3%) and waste marble dust powder (MD) (5%, 10% and 15%) was incorporated as a fractional substitution of cement in the concrete matrix. Design/methodology/approach In this experimental study, 10 cementitious blends were prepared and tested for compressive strength, flexural strength, splitting tensile strength and static modulus of elasticity. The microstructural characteristics of these blends were also explored using a scanning electron microscope along with energy dispersive spectroscopy and X-ray reflection. Findings The results indicate an enhancement in mechanical properties and refinement in pore structure due to improved pozzolanic activities of NS and the filling effect of MD. Originality/value To the best of the authors’ knowledge, no study has reported the mechanical and microstructural behavior of concrete containing marble and NS.

High temperature corrosion behaviour of aluminised FC 25 cast iron using pack cementation

2019 ◽  
Vol 66 (2) ◽  
pp. 236-241 ◽  
Author(s):  
Somrerk Chandra-Ambhorn ◽  
Neramit Krasaelom ◽  
Tummaporn Thublaor ◽  
Sirichai Leelachao
Keyword(s):  
Cast Iron ◽  
High Temperature ◽  
Corrosion Behaviour ◽  
Mass Gain ◽  
High Temperature Corrosion ◽  
Pack Cementation ◽  
X Ray Diffraction ◽  
Content Type ◽  
X Ray ◽  
Seat Insert

Purpose This study aims to apply the pack cementation to develop the Fe-Al layers on the surface of FC 25 cast iron in order to increase the high-temperature corrosion resistance of the alloy. Design/methodology/approach Pack cementation was applied on the surface of FC 25 cast iron at 1,050°C. The bare and aluminised alloys were subjected to the oxidation test in 20 per cent O2-N2 at 850 °C. Scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD) were used for characterisation. Findings The layers of pack cementation consisted of Fe2Al5, FeAl2 and FeAl, and solid solution alloyed with Al. The oxidation kinetics of the bare cast iron was parabolic. Mass gain of the aluminised cast iron was significantly decreased compared with that of the bare cast iron. This was because of the protective alumina formation on the aluminised alloy surface. Al in the Fe–Al layer also tended to be homogenised during oxidation. Originality/value Even though the aluminising of alloys was extensively studied, the application of that process to the FC 25 cast iron grade was originally developed in this work. The significantly reduced mass gain of the aluminised FC 25 cast iron makes the studied alloy be promising for the use as a valve seat insert in an agricultural single-cylinder four-stroke engine, which might be run by using a relatively cheaper fuel, i.e. LPG, but as a consequence requires the higher oxidation resistance of the engine parts.

Effect of Hot Forging and Different Cooling Rates on the Microstructure, Mechanical Properties of Carbon Steel Containing 0.8 and 1.2Al

2014 ◽  
Vol 622-623 ◽  
pp. 174-178
Author(s):  
Ahmed Ismail Zaky Farahat ◽  
Mohamed Kamal Elfawkhry
Keyword(s):  
Mechanical Properties ◽  
Carbon Steel ◽  
Mechanical Testing ◽  
Room Temperature ◽  
Induction Furnace ◽  
Hot Forging ◽  
X Ray Diffraction ◽  
Cooling Rates ◽  
X Ray ◽  
Sem Microstructure

Two alloys of steel containing nominally 0.45C-1.0Si-2.0Mn-0.8Al and 1.2Al were cast in open air induction furnace. Dilatation testing was carried out to recognize the effect on Aluminum on the different critically transformation temperatures. The alloys were hot forged at 1200°C and then subjected to different cooling rates. Mechanical testing was carried out at room temperature. Optical and SEM microstructure were observed. X-ray diffraction was conducted to observe the microstructure constituents.

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