Effects of Ultrasonic Treatment on the Microstructure and Mechanical Properties of Mg-3Y-3.5Sm-2Zn-0.6Zr (wt %) Alloy

Ultrasonic treatment (UST) was applied in the smelting process of Mg-3Y-3.5Sm-2Zn-0.6Zr (wt %) alloy and the microstructure as well as mechanical properties of the experimental alloy were investigated. Results showed that the effect of UST on grain refinement was obvious, and the distribution of the second phases along grain boundary became discontinuous. The width of the grain boundary precipitates decreased after UST. The contents of solute elements within grains increased, and the morphologies of Zr-rich compounds and Y-rich compounds both at grain boundaries and within grains changed after UST. The mechanical properties of the experimental alloy after UST were significantly improved. The ultimate tensile strength (UTS) was 265 MPa, the tensile yield strength (TYS) was 171 MPa, and the elongation (EL) was 11%. The mechanism of UST of the alloy can be attributed to the combined effects of cavitation-induced heterogeneous nucleation and melt convection induced by acoustic streaming, resulting in the refinement of grains and the grain boundary precipitates, which promoted the improvement of mechanical properties.

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A New Ultra-High-Strength AB83 Alloy by Combining Extrusion and Caliber Rolling

Materials ◽

10.3390/ma13030709 ◽

2020 ◽

Vol 13 (3) ◽

pp. 709

Author(s):

Shuaiju Meng ◽

Lishan Dong ◽

Hui Yu ◽

Lixin Huang ◽

Haisheng Han ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

High Strength ◽

Tensile Yield Strength ◽

Bimodal Microstructure ◽

Combined Effects ◽

Basal Texture ◽

Bimodal Structure ◽

The Matrix ◽

Superior Mechanical Properties

An exceptionally high-strength rare-earth-free Mg–8Al–3Bi (AB83) alloy was successfully fabricated via extrusion and caliber rolling. After three-pass caliber rolling, the homogenous microstructure of the as-extruded AB83 alloy was changed to a necklace-like bimodal structure consisting of ultra-fine dynamic recrystallized (DRXed) grains and microscale deformed grains. Additionally, both Mg17Al12 and Mg3Bi2 nanoprecipitates, undissolved microscale Mg17Al12, and Mg3Bi2 particles were dispersed in the matrix of caliber-rolled (CRed) AB83 alloy. The CRed AB83 sample demonstrated a slightly weakened basal texture, compared with that of the as-extruded sample. Consequently, CRed AB83 showed a tensile yield strength of 398 MPa, an ultimate tensile strength of 429 MPa, and an elongation of 11.8%. The superior mechanical properties of the caliber-rolled alloy were mainly originated from the combined effects of the necklace-like bimodal microstructure containing ultra-fine DRXed grains, the homogeneously distributed nanoprecipitates and microscale particles, as well as the slightly modified basal texture.

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Investigation on Microstructures and Mechanical Properties of the Hypoeutectic Al-10Si-0.8Fe-XEr Alloy

Scanning ◽

10.1155/2020/9147871 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Peng Tang ◽

Yiyuan Liu ◽

Yanjun Zhao ◽

Zhiliu Hu ◽

Huachun Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Secondary Phase ◽

Metallographic Analysis ◽

Analysis Techniques ◽

Microstructure Modification ◽

Primary Si ◽

Eutectic Si ◽

Second Phases ◽

The Mean

In this paper, the effect of Er addition (0.2, 0.5, 0.65, 0.8, 1.0, and 1.5 wt. %) on the microstructure evolution and tensile properties of as-cast hypereutectic Al-10Si-0.8Fe alloy was investigated. The phases and their morphologies in these alloys were identified by XRD and SEM equipped with EDX with the help of metallographic analysis techniques; the length of the secondary phase (LSP) and secondary dendrite arm spacing (SDAS) of α-Al grain were quantified. The results indicated that the second phases (primary Si, eutectic Si, and iron-rich phases) and α-Al grain were significantly refined when the addition of Er increased from 0 to 0.8 wt. %. The mean LSP and SADS values were decreased to a minimum value when the Er addition reached 0.8 wt. %. However, the second phases and α-Al grain became coarser when the level of Er increased more than 0.8 wt. %. The analysis of XRD shows that Er mainly exists in the form of Er2Si compound. The microstructure modification also has a significant effect on the mechanical properties of the alloy. The yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) increase from 52.86 MPa, 163.84 MPa, and 3.45% to 71.01 MPa, 163.84 MPa, and 5.65%, respectively. From the fracture surface, the promotions of mechanical properties are due to the dispersion and pinning reinforcement caused by the Er2Si phase.

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Influence of Stirring Time and Holding Time on Microstructure and Properties of the A356 Alloy Modified by Sc

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.687 ◽

2013 ◽

Vol 750-752 ◽

pp. 687-690 ◽

Cited By ~ 1

Author(s):

Su Zhang ◽

Gang Yang ◽

Jian Hong Yi ◽

Hong Yan

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Grain Boundary ◽

Eutectic Silicon ◽

A356 Alloy ◽

Holding Time ◽

Test Results ◽

Modification Effect ◽

Microstructure And Mechanical Properties ◽

Stirring Time

Effects of the holding time and the stirring time on the microstructure and mechanical properties of A356 alloy modified by Sc are researched. According to the test results, most of the eutectic silicon phases have changed to the shape of creeping point, dispersed in the grain boundary of α (Al) phase while stirring 1 minute, in which case both the tensile strength and elongation reach the highest, resulting in the best modification effect. The results also indicate that microstructure and mechanical properties of the alloy reach are the best modification effect when the melt is held 15 minute. It can be known that the optimal stirring time is 1 minute and the optimal holding time is 15 minute in the experiment condition of the work.

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Variation of Mechanical Properties of AlSi20Cu2Ni1 Alloy with Co Addition and Ultrasonic Treatment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.922.638 ◽

2014 ◽

Vol 922 ◽

pp. 638-644

Author(s):

Meng Sha ◽

Shu Sen Wu ◽

Ping An ◽

You Wu Mao

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Liquidus Temperature ◽

Volume Fraction ◽

Fish Bone ◽

Solute Diffusion ◽

Chinese Script ◽

Combined Effects ◽

Preferential Growth ◽

Co Addition

The combined effects of the Co addition and Ultrasonic Vibration (USV) on microstructure and properties of Al–20Si–2Cu–1Ni–0.6Mg alloy were studied in this paper. The volume fraction of Co-bearing intermetallic compounds was increased with the increasing of Co content when various levels of Co (from 0% to 1.5%) added respectively into the alloys whether they formed in traditional casting or with USV treatment. The Co-bearing compounds presented as Chinese script or granular when Co was equal or less than 0.7% and turned into dendritic or fish-bone shape when Co was more than 0.7%. USV treatment applied around liquidus temperature of the melt could lead to a refinement of Co-containing compounds by promoting nucleus formation, hindering preferential growth on certain direction, and enlarging solute diffusion coefficient. The addition of equal or less than 0.7% Co, as well as application of USV is very effective in promotion of tensile strength of the hypereutectic Al–Si alloys.

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Combined Effects of Cellulose Nanofiber Nucleation and Maleated Polylactic Acid Compatibilization on the Crystallization Kinetic and Mechanical Properties of Polylactic Acid Nanocomposite

Polymers ◽

10.3390/polym13193226 ◽

2021 ◽

Vol 13 (19) ◽

pp. 3226

Author(s):

Siti Shazra Shazleen ◽

Lawrence Yee Foong Ng ◽

Nor Azowa Ibrahim ◽

Mohd Ali Hassan ◽

Hidayah Ariffin

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Polylactic Acid ◽

Crystallization Kinetics ◽

Crystallization Kinetic ◽

Crystallization Rate ◽

Combined Effects ◽

Dsc Analysis ◽

Scanning Calorimetry ◽

Isothermal Crystallization Kinetics

This work investigated the combined effects of CNF nucleation (3 wt.%) and PLA-g-MA compatibilization at different loadings (1–4 wt.%) on the crystallization kinetics and mechanical properties of polylactic acid (PLA). A crystallization kinetics study was done through isothermal and non-isothermal crystallization kinetics using differential scanning calorimetry (DSC) analysis. It was shown that PLA-g-MA had some effect on nucleation as exhibited by the value of crystallization half time and crystallization rate of the PLA/PLA-g-MA, which were increased by 180% and 172%, respectively, as compared to neat PLA when isothermally melt crystallized at 100 °C. Nevertheless, the presence of PLA-g-MA in PLA/PLA-g-MA/CNF3 nanocomposites did not improve the crystallization rate compared to that of uncompatibilized PLA/CNF3. Tensile strength was reduced with the increased amount of PLA-g-MA. Contrarily, Young’s modulus values showed drastic increment compared to the neat PLA, showing that the addition of the PLA-g-MA contributed to the rigidity of the PLA nanocomposites. Overall, it can be concluded that PLA/CNF nanocomposite has good performance, whereby the addition of PLA-g-MA in PLA/CNF may not be necessary for improving both the crystallization kinetics and tensile strength. The addition of PLA-g-MA may be needed to produce rigid nanocomposites; nevertheless, in this case, the crystallization rate of the material needs to be compromised.

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Optimizing the Microstructure and Mechanical Properties of Vacuum Counter-Pressure Casting ZL114A Aluminum Alloy via Ultrasonic Treatment

Materials ◽

10.3390/ma13194232 ◽

2020 ◽

Vol 13 (19) ◽

pp. 4232

Author(s):

Gang Lu ◽

Pengpeng Huang ◽

Qingsong Yan ◽

Pian Xu ◽

Fei Pan ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Aluminum Alloy ◽

Ultrasonic Treatment ◽

Eutectic Silicon ◽

Primary Phase ◽

Pressure Casting ◽

Counter Pressure ◽

Casting Aluminum Alloy ◽

Casting Aluminum

The effect of ultrasonic temperature on density, microstructure and mechanical properties of vacuum counter-pressure casting ZL114A alloy during solidification was investigated by optical microscopy (OM), scanning electron microscope (SEM) and a tensile test. The results show that compared with the traditional vacuum counter-pressure casting aluminum alloy, the primary phase and eutectic silicon of the alloy with ultrasonic treatment has been greatly refined due to the dendrites broken by ultrasonic vibration. However, the refining effect of ultrasonic treatment on vacuum counter-pressure casting aluminum alloy will be significantly affected by ultrasonic temperature. When the ultrasonic temperature increases from 680 °C to 720 °C, the primary phase is gradually refined, and the morphology of eutectic silicon also changes from coarse needle-like flakes to fine short rods. With a further increase in the ultrasonic temperature, the microstructure will coarse again. The tensile strength and elongation of vacuum counter-pressure casting ZL114A alloy increases first and then decreases with the increase of ultrasonic temperature. The optimal mechanical properties were achieved with tensile strength of 327 MPa and the elongation of 5.57% at ultrasonic temperature of 720 °C, which is 6.3% and 8.2%, respectively, higher than that of alloy without ultrasonic treatment.

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Microstructures and Mechanical Properties of Mg-Zn-RE-Ca Casting Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.510-511.214 ◽

2006 ◽

Vol 510-511 ◽

pp. 214-217 ◽

Cited By ~ 9

Author(s):

Joong Hwan Jun ◽

Bong Koo Park ◽

Jeong Min Kim ◽

Ki Tae Kim ◽

Woon Jae Jung

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Elevated Temperatures ◽

Tensile Tests ◽

Eutectic Phase ◽

Tensile Yield Strength ◽

X Ray ◽

Casting Alloys ◽

Microstructures And Mechanical Properties ◽

Strong Segregation

Influences of Ca addition on microstructures and mechanical properties at room and elevated temperatures up to 300oC were investigated for ZE41 (Mg-4%Zn-1%Zn)-(0~1.0)%Ca permanent mould casting alloys, based on the results from X-ray diffractometry (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) and tensile tests. The microstructure of ZE41 alloy is characterized by dendritic α-(Mg) grains surrounded by Mg7Zn3-based eutectic network phase. The average size of α grains decreases continuously with an increase in Ca content. The Ca-containing ZE41 alloys have Mg7Zn3-(RE)-(Ca) eutectic phase, in which Ca is distributed inhomogeneously owing to its strong segregation power. It is noteworthy that tensile yield strength (YS) for the ZE41 alloy was enhanced with increasing Ca content at all temperatures up to 300oC, which demonstrates that Ca can play a beneficial role in improving its tensile strength at room and elevated temperatures. The ZE41 alloy with 0.5%Ca showed the highest ultimate tensile strength (UTS) at room temperature, but in the range of 175 to 300oC, the higher the Ca content, the greater the UTS. The improved tensile strength of the Ca-containing ZE41 alloy would be caused by the refined α grains and higher thermal stability of the Mg7Zn3-(RE)-(Ca) eutectic phase.

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Experimental Study of Cu-Al-Ni-Fe-Mn Aluminum Bronze Strengthen by Ce

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.721.177 ◽

2013 ◽

Vol 721 ◽

pp. 177-183

Author(s):

Jia Ming Ji ◽

Guo Cui Meng ◽

Yuan Yong Lu ◽

Jing Wu

Keyword(s):

Mechanical Properties ◽

Experimental Study ◽

Tensile Strength ◽

Wear Resistance ◽

Rare Earth ◽

Grain Boundary ◽

Aluminum Bronze ◽

Bronze Alloy ◽

Alloy Material ◽

Ce Content

Cu-Ce intermediate alloy was added to aluminum bronze alloy which contains Al, Ni, Fe and Mn to form a novel aluminum-bronze material of Cu-Al-Ni-Fe-Mn. The influence of the different concentrations of rare earth cerium on the mechanical properties, wear resistance and microstructures of as cast Cu-Al-Ni-Fe alloy has been investigated. The results indicate that the addition of an appropriate Ce content can effectively refine the microstructure and improve the tensile strength, ductility and wear resistance. When the alloy is added by 0.15% Ce, the grain is small, sleek and uniform distribution, the tensile strength, ductility and wear resistance of the alloy material can reach to the best performance, in which tensile strength is 731Mpa and elongation is 34%. However, when the rare earth cerium add to more than 0.20%, the block shape and shred of organization becomes large, which leads to the grain boundary roughening. The tensile strength, ductility and wear resistance are declining.

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The Effect of Extrusion Temperatures on Microstructure and Mechanical Properties of Mg-1.3Zn-0.5Ca (wt.%) Alloys

Crystals ◽

10.3390/cryst11101228 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1228

Author(s):

Honglin Zhang ◽

Zhigang Xu ◽

Laszlo J. Kecskes ◽

Sergey Yarmolenko ◽

Jagannathan Sankar

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Ultimate Tensile Strength ◽

Yield Strength ◽

Volume Fraction ◽

Fiber Texture ◽

Extrusion Ratio ◽

Tensile Yield Strength ◽

Microstructure And Mechanical Properties ◽

Average Size

The present work mainly investigated the effect of extrusion temperatures on the microstructure and mechanical properties of Mg-1.3Zn-0.5Ca (wt.%) alloys. The alloys were subjected to extrusion at 300 °C, 350 °C, and 400 °C with an extrusion ratio of 9.37. The results demonstrated that both the average size and volume fraction of dynamic recrystallized (DRXed) grains increased with increasing extrusion temperature (DRXed fractions of 0.43, 0.61, and 0.97 for 300 °C, 350 °C, and 400 °C, respectively). Moreover, the as-extruded alloys exhibited a typical basal fiber texture. The alloy extruded at 300 °C had a microstructure composed of fine DRXed grains of ~1.54 µm and strongly textured elongated unDRXed grains. It also had an ultimate tensile strength (UTS) of 355 MPa, tensile yield strength (TYS) of 284 MPa, and an elongation (EL) of 5.7%. In contrast, after extrusion at 400 °C, the microstructure was almost completely DRXed with a greatly weakened texture, resulting in an improved EL of 15.1% and UTS of 274 MPa, TYS of 220 MPa. At the intermediate temperature of 350 °C, the alloy had a UTS of 298 MPa, TYS of 234 MPa, and EL of 12.8%.

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Microstructure and Formability of Different-Speeds Rolled AZ31 Mg Sheet

Materials Science Forum ◽

10.4028/www.scientific.net/msf.544-545.407 ◽

2007 ◽

Vol 544-545 ◽

pp. 407-410 ◽

Cited By ~ 3

Author(s):

Jae Seol Lee ◽

Hyeon Taek Son ◽

Young Kyun Kim ◽

Ik Hyun Oh ◽

Chang Seog Kang ◽

...

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Yield Strength ◽

Grain Boundary ◽

Microstructure Evolution ◽

Hot Rolling ◽

Potential Application ◽

Plastic Anisotropy ◽

Mg Alloys ◽

Az31 Mg Alloy

The aims of this study ares to investigate the microstructure evolution of AZ31 Mg alloys with normal rolling and different speeds rolling during hot rolling affects microstructure, texture and mechanical properties of AZ31 Mg alloy. In the microstructures of as-rolled both samples, twins are clearly apparent, small and recrystallized grains are visible along some grain boundary and twinned regions. The tensile strength and yield strength of DSR sample were slightly higher than that of NR sample. Also, in the case of the NR sample, tensile strength indicated different values to the rolling directions. From this result, NR sample compared to DSR sample strongly indicated to the plastic anisotropy tendency. Therefore, it is noted that DSR sample could be presented to the good formability, comparing to the NR sample. DSR samples deformed at 473K and 523K could be perfectly formed, indicating the potential application of the DSR process to improve formability of the Mg alloys at warm temperatures.

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