Influence of Zn Content on the Microstructure and Properties of As-Annealed Al-Mn-Si Alloys

2012 ◽  
Vol 560-561 ◽  
pp. 937-942
Author(s):  
Shao Hai Kang ◽  
Dong Yan Ding ◽  
Yong Jin Gao

The effect of Zn addition on the microstructure, tensile properties and electrochemical properties of as-annealed Al-Mn-Si alloy was investigated through TEM observations, anodization metallography, tensile tests and Tafel polarization analysis. High density precipitates were found in the Zn-containing alloys and the alloy with 1.5 % Zn had the most uniform precipitation. The Zn element could restrain recrystallization of the alloy. Tensile test results indicated that Zn has a great effect on tensile strength of Al-Mn-Si alloy. The alloy with 1.8 % Zn addition had the highest ultimate tensile strength. The electrochemical testing results indicated that Zn element had great impact on the corrosion potential of the as-annealed alloys tested in 0.5% NaCl solutions. Alloying with Zn element could make the corrosion potential shift to negative direction but increase the resistance to pitting corrosion

The purpose of this study is to identify the Osgood’s coefficient of species and the Modified Osgood Equation for Acacia mangium. Acacia mangium trees were cut to produce oven-dried Small Clear Specimens that were then tested until fracture. Results were gathered from static tensile tests in the direction parallel (0° angle), perpendicular (90° angle) and at 30° angle to the wood grain. All test results confirmed that the Acacia mangium wood is brittle as there was no obvious necking observed on the test specimens. From the static testing, the Osgood’s coefficient of species for Acacia mangium, (a), is identified algebraically to be 0.49. Acacia mangium, by nature, has a significant difference in the strengths parallel and perpendicular to the grain line. The finalized results of the Ultimate Tensile Strength for 15-year old Acacia mangium demonstrated that the Ultimate Tensile Strength in parallel and perpendicular to the grain directions are 143.87 MPa and 6.32 MPa respectively, while the Ultimate Tensile Strength at 30° grain angle is 32.985 MPa. An extreme reduction of 95.6% of the Ultimate Tensile Strength was identified between 0° and 90° grain angles with a decreased value from 143.87 MPa to 6.32 MPa.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3943
Author(s):  
Hana Šebestová ◽  
Petr Horník ◽  
Šárka Mikmeková ◽  
Libor Mrňa ◽  
Pavel Doležal ◽  
...  

The presence of Al-Si coating on 22MnB5 leads to the formation of large ferritic bands in the dominantly martensitic microstructure of butt laser welds. Rapid cooling of laser weld metal is responsible for insufficient diffusion of coating elements into the steel and incomplete homogenization of weld fusion zone. The Al-rich regions promote the formation of ferritic solid solution. Soft ferritic bands cause weld joint weakening. Laser welds reached only 64% of base metal's ultimate tensile strength, and they always fractured in the fusion zone during the tensile tests. We implemented hybrid laser-TIG welding technology to reduce weld cooling rate by the addition of heat of the arc. The effect of arc current on weld microstructure and mechanical properties was investigated. Thanks to the slower cooling, the large ferritic bands were eliminated. The hybrid welds reached greater ultimate tensile strength compared to laser welds. The location of the fracture moved from the fusion zone to a tempered heat-affected zone characterized by a drop in microhardness. The minimum of microhardness was independent of heat input in this region.


2016 ◽  
Vol 852 ◽  
pp. 33-37
Author(s):  
Xing Long Xu ◽  
Dong Yan Ding ◽  
Wen Long Zhang ◽  
Yong Jin Gao ◽  
Guo Zhen Chen ◽  
...  

7072Al is widely used as cladding layer for heat-transfer components. In this paper, the microstructure, mechanical properties and electrochemical properties of simulated-brazing 7072Al alloy with Zn addition were investigated. Transmission electron microscopy (TEM) observations revealed that, in the simulated-brazing state, Zn-addition could promote the precipitation in the 7072Al alloy. Tensile testing results indicated that, in comparison with 7072Al alloy, the mechanical properties were improved after Zn-addition. Electrochemical testing results revealed that the simulated-brazing alloy showed a negative shift of the corrosion potential with the addition of Zn element.


Author(s):  
Arnaud Blouin ◽  
Mathieu Couvrat ◽  
Félix Latourte ◽  
Julian Soulacroix

In the framework of a pressurized water reactor primary loop replacement, elbows of different types were produced in cast austenitic stainless steel grade Z3CN 20-09 M. For that type of component, acceptance tests to check the sufficient mechanical properties include room and hot temperature tensile tests, following the RCC-M CMS – 1040 and EN 10002 specifications. A large test campaign on standard 10mm diameter specimens was performed and exhibited a high scattering in yield stress and ultimate tensile strength values. As a consequence, some acceptance tensile tests failed to meet the required minimal values, especially the ultimate tensile strength. Optical and electronic microscopy revealed that the low values were due to the presence of very large grain compared to the specimen gage diameter. However, tensile tests strongly rely on the hypothesis that the specimen gage part can be considered as a representative volume element containing a number of grains large enough so that their variation in size and orientation gives a homogeneous response. To confirm the origin of the scattering, a huge experimental tensile test campaign with specimens of different diameters was conducted. In parallel, FE calculations were also performed. From all those results, it was concluded that it was necessary to improve the RCC-M code for that type of test for cast stainless steel: to do so, a modification sheet was sent and is being investigated by AFCEN.


2013 ◽  
Vol 704 ◽  
pp. 114-119
Author(s):  
Jing Feng ◽  
Dong Yan Ding ◽  
Wen Long Zhang ◽  
Yong Jin Gao ◽  
Guo Zhen Chen ◽  
...  

The microstructure and electrochemical properties of Ce-containing 7072 Al alloy were investigated through transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Tafel polarization analysis. It was found that Ce alloying could result in a formation of finer grains in the simulated brazing alloys. The 7072 Al alloy with 0.15% Ce had desirable distribution of precipitates. The electrochemical testing results indicated that Ce element had a great impact on the corrosion potential of the alloy tested in 0.5% NaCl solution. Alloying with 0.15% Ce element could make the corrosion potential shift to inert direction and reduce the corrosion current density. An excessive Ce addition could weaken its positive effect on the corrosion resistance of the Ce-containing alloy.


2013 ◽  
Vol 829 ◽  
pp. 583-588 ◽  
Author(s):  
Ali Dalirbod ◽  
Yahya A. Sorkhe ◽  
Hossein Aghajani

Alumina dispersion hardened copper-base composite was fabricated by internal oxidation method. The high temperature tensile fracture of Cu-Al2O3 composite was studied and tensile strengths were determined at different temperatures of 600, 680 and 780 °C. Microstructure was investigated by means of optical microscope and field emission scanning electron microscope (FESEM) with energy dispersive spectroscopy (EDS). Results show that, ultimate tensile strength and yield strength of copper alumina nanocomposite decrease slowly with increasing temperature. The yield strength reaches 119 MPa and ultimate tensile strength reaches 132 MPa at 780 °C. Surface fractography shows a dimple-type fracture on the fracture surface of the tensile tests where dimple size increases with increasing testing temperature and in some regions brittle fracture characteristics could be observed in the fracture surface.


2021 ◽  
Vol 2 (12 (110)) ◽  
pp. 22-31
Author(s):  
Agus Widyianto ◽  
Ario Sunar Baskoro ◽  
Gandjar Kiswanto ◽  
Muhamad Fathin Ginanjar Ganeswara

Orbital pipe welding was often used to manufacture piping systems. In orbital pipe welding, a major challenge is the welding torch’s position during the welding process, so that additional methods are needed to overcome these challenges. This paper discusses the influence of welding sequence and welding current on distortion, mechanical properties and metallurgical observations in orbital pipe welding with SS 316L pipe square butt joints. The variation of the orbital pipe welding parameters used is welding current and welding sequence. The welding current used is 100 A, 110 A, and 120 A, while the welding sequence used is one sequence, two sequences, three sequences, and four sequences. The welding results will be analyzed from distortion measurement, mechanical properties test and metallurgical observations. Distortion measurements are made on the pipe before welding and after welding. Testing of mechanical properties includes tensile tests and microhardness tests, while metallurgical observations include macrostructure and microstructural observations. The results show that maximum axial distortion, transverse distortion, ovality, and taper occurred at a welding current of 120 A with four sequences of 445 µm, 300 µm, 195 µm, and 275 µm, respectively. The decrease in ultimate tensile strength is 51 % compared to the base metal’s ultimate tensile strength. Horizontal and vertical microhardness tests show that welding with one sequence produces the greatest microhardness value, but there is a decrease in the microhardness value using welding with two to four sequences. Orbital pipe welding results in different depths of penetration at each pipe position. The largest and smallest depth of penetration was 4.11 mm and 1.60 mm, respectively


2021 ◽  
Vol 55 (5) ◽  
Author(s):  
Juan José Galán ◽  
Nuria Varela-Fernández ◽  
Manuel Ángel Graña-López ◽  
Almudena Filgueira-Vizoso ◽  
Ana García-Diez

The objective of this work was to study the suitability of three types of cast iron for the manufacture of a ship engine: EN-GJS-500-7U for the manufacture of the engine block, EN-GJS-400-15U for the cylinder head and EN-GJL-200 for the liner. Tensile tests were carried out to obtain the ultimate tensile strength (UTS) of each material. The results for the UTS were: 460 MPa for EN-GJS-500-7U, 390 MPa for EN-GJS-400-15U and 170 MPa for EN-GJL-200. Likewise, Brinell-hardness measurements were carried out and the elements present in the materials were determined with spectrometry. Finally, the size of graphite particles in each sample was determined.


2020 ◽  
Vol 23 (13) ◽  
pp. 2803-2812
Author(s):  
Zhao Chen ◽  
Somayeh Nassiri ◽  
Anthony Lamanna

A modified concrete capacity design method is available to predict the ultimate tensile strength ( Nu) of screw anchors. Screw anchors commonly fail in a combination of concrete breakout and pullout modes. This combined mode is not distinguished from the breakout mode in the modified concrete capacity design method, which may cause confusions to designers. To investigate the Nu of the combined mode ( Ncomb), this study included 144 unconfined tension tests on screw anchors from three manufacturers in three diameters and two effective embedment depths ( hef) per diameter. Approximately 80% of the tested anchors failed in the combined mode. The differences in Ncomb among the three manufacturers were insignificant despite their varied thread design. Ncomb was found to be linearly correlated to the parameter hef 1.3 but was found independent of the anchor diameter. A regression model was developed to specifically predict Ncomb. The model showed a good fit with the test results.


Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1212
Author(s):  
Xiong ◽  
Yang ◽  
Deng ◽  
Li ◽  
Li ◽  
...  

The effect of Ca addition on the microstructure, mechanical properties, and corrosion behaviors of the extruded Mg–7Li–3Al alloys was investigated. The results showed that the extruded Mg–7Li–3Al–xCa alloys consisted of α-Mg (hcp) + β-Li (bcc) matrix phases and Al2Ca. With increasing Ca content, the amount and morphology of the Al2Ca phase changed significantly. The grains of the extruded Mg–7Li–3Al–xCa alloys were refined by dynamic recrystallization during the extrusion process. The tensile tests results indicated that the extruded Mg–7Li–3Al–0.4Ca alloy exhibited favorable comprehensive mechanical properties; its ultimate tensile strength was 286 MPa, the yield strength was 249 MPa, and the elongation was 18.7%. The corrosion results showed that this alloy with 0.4 wt.% Ca addition exhibited superior corrosion resistance, with a corrosion potential Ecorr of −1.48742 VVSE, attributed to the formation of protective Al2Ca phases.


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