Phase Refinement Research Articles

Fabrication Techniques and the Formation Mechanism of Nanoparticles and Nanoclusters in Metal Materials

Continuous innovation in the design of metallic materials is essential for further progress in aerospace, automotive, construction, and shipping. Fine grain strengthening is considered to increase the strength of metals without losing plasticity. However, many fabrication techniques are restricted to very small sizes. Recently, the introduction of in situ nanoparticles with coherent or semi-coherent interfaces in the metallic matrix achieves simultaneous enhancement of the strength and ductility of metallic materials. In this review, the focus is on fabrication techniques and the formation mechanism of nanoparticles and nanoclusters in metal materials. The effects of nanoparticles on grain refinement, inhibiting segregation, second phase, and inclusion refinement are discussed, and the mechanism of simultaneous improvement in the strength and ductility of nanostructured metal materials is briefly covered. Finally, we provide a summary and outline of the possible direction for further advances in this research field.

Effect of nitrogen pressure on the microstructure, mechanical and electrochemical properties of CrAlN coatings deposited by filter cathode vacuum arc

CrAlN coatings were prepared on Al–Si alloys using filter cathode vacuum arc deposition technique with nitrogen as the reactive gas and Cr25Al75 alloy target as the arc source. The effect of nitrogen pressure on the microstructure, mechanical properties and electrochemical properties of the coatings had been systematically studied. The results showed that the composition, structure and performance of the CrAlN coating depended on the nitrogen pressure. As the nitrogen pressure increased, the Al and Cr content decreased while the N content increased slowly in the coating. Meanwhile, the phase structure gradually changed from AlN phase to CrN phase. The hardness of the CrAlN coating increased significantly with the increase of nitrogen pressure from 0.04 to 0.06 Pa due to the formation of CrN phase and grain refinement. However, further increasing the nitrogen pressure to 0.07 Pa, the hardness was reduced owing to the deterioration of the surface quality caused by target poisoning. Moreover, the adhesion strength of the coating gradually decreases, and the corrosion resistance of the CrAlN coating first increased and then decreased with increasing the nitrogen pressure. The CrAlN coating deposited at a nitrogen pressure of 0.05 Pa had the best corrosion resistance, with the highest polarization resistance, charge transfer resistance and pore resistance, which was related to the combined effect of great compactness and AlN-dominant phase structure in the coating.

Development of a novel high strength and toughness Al–Cu–Li alloy casting billet with a new process

In this study, a novel Al–5Cu-0.6Li-0.5Mn-0.3Mg-0.15Ti alloy was developed, in which Li is as low as 0.6 wt% and Ti is added, no Ag, Zn, Zr, RE, etc., and high-performance Al–Cu–Li alloy casting billets were prepared by squeeze casting (SC) with ultrasonic treatment (UT). The results show that compared with traditional gravity casting (GC), the porosity and compositional segregation in the SC billets are significantly reduced, and the grain size is also reduced from 80 μm to 38 μm, especially the microstructure of UT + SC billets is further optimized. After UT + SC, the ultimate tensile strength (UTS), yield strength (YS) and elongation of Al–Cu–Li alloy billets are 300 MPa, 190 MPa and 16.5%, which are 27.1%, 35.7% and 230% higher than those of the GC billets, and these as-cast properties are increased by 13.2%, 15.2% and 37.5%, compared with Li-free Al–5Cu-0.5Mn-0.3Mg-0.15Ti alloy billet prepared by UT + SC, respectively. The improvement of the strength and elongation of Al–Cu–Li alloy billet prepared by UT + SC is attributed to the reduction of porosity, grain refinement and uniform distribution of second phases.

Corrosion properties of ECAP-processed Mg−Al−Ca−Mn alloys with separate Al2Ca and Mg2Ca phases

To investigate the effect of separate Al2Ca and Mg2Ca phases on the corrosion properties of Mg−Al−Ca−Mn alloys, OM, SEM, immersion and electrochemical tests were conducted on the as-cast and ECAP Al2Ca-containing (2Ca) and Mg2Ca-containing (4Ca) alloys. At the beginning of corrosion, the two as-cast alloys are corroded slowly compared with ECAP alloys. With prolonging the corrosion time, the corrosion of ECAP alloys becomes slighter than that of as-cast alloys, which is mainly ascribed to the dispersion and refinement of the second phase in ECAP alloys. Moreover, the corrosion degree of 2Ca alloys is always slighter than that of 4Ca alloys, suggesting that Al2Ca phase is more beneficial to the enhancement of corrosion resistance of Mg−Al−Ca−Mn based alloys than Mg2Ca phase. Finally, based on the examinations of corrosion surface and electrochemical testing results, different corrosion mechanisms caused by the distributions and morphology of Al2Ca and Mg2Ca phases are discussed.

Microstructure evolution and mechanical properties of CNT/Al composite joints via friction stir welding

ABSTRACT The traditional fusion welding of carbon nanotubes (CNTs) reinforcement aluminium matrix composites has serious welding defects due to the violent interfacial reaction and the brittle secondary phase. In this paper, friction stir welding (FSW), a solid-phase welding technique, was applied to join the CNT/Al matrix composites. The result shows that the tensile strength of the FSW joint fabricated at 800 rev min–1 and 100 mm min–1 is 511 MPa, reaching 92.1% of the CNT/Al composites. After FSW, the original CNTs were damaged and formed the nano Al4C3 phase. Orowan strengthening of the Al4C3 phase, dislocation strengthening and grain refinement of FSW are the predominant strengthening mechanism for the joints. The great interfacial bonding between nano Al4C3 and matrix benefits the joint mechanical properties as well.

Exploiting an as-extruded fine-grained Mg-Bi-Mn alloy with strength-ductility synergy via dilute Zn addition

Here, a new Mg-1Bi-1Mn-0.3Zn (BMZ110, wt%) wrought alloy designed by the dilute addition of Zn subjected to an appropriate extrusion processing that showed an excellent strength-ductility synergy at room temperature. The main results included four aspects as follows: 1) With dilute Zn addition, the as-cast BMZ110 alloy was refined into an approximately equiaxed-grained structure, since the solid solution of Zn provided a relatively high growth restriction factor. 2) The as-extruded BMZ110 alloy exhibited the finer average grain size and weaker basal texture intensity than the as-extruded BM11 alloy without Zn. The co-segregation of Bi and Zn solutes into grain boundaries was observed to impede grain growth during extrusion and further weaken texture intensity. Moreover, Zn atoms incorporated into Mg3Bi2 phases by replacing Bi atoms increasing the nucleation rate of Mg3Bi2 phases and refining their sizes. 3) Compared with the as-extruded BM11 alloy, the as-extruded BMZ110 alloy demonstrated the higher yield strength (~ 283.4 MPa), ultimate strength (~ 366.2 MPa) and elongation-to-failure (~ 26%). The size refinement of grains and second phases contributed to an extra strength increments. Grain boundary segregation enhanced grain boundary cohesion not only reducing the number density of grain boundary cracks, but also activating more slip modes and grain rotation for increasing the ductility. 4) The as-extruded BMZ110 alloy had the higher grain growth resistance than the as-extruded BM11 alloy during annealing. Solute segregation offered an effective obstacle to restrict grain boundary migration enlarging the activation energy (~ 112.2 kJ/mol) and further delaying the grain growth. Therefore, this work will be helpful for the development of new high performance low-alloyed Mg-Bi based wrought alloys to achieve extensive applications in industries.

Modification and refinement of Fe-containing phases, mechanical properties and strengthening mechanisms in Al–Fe alloys via Cr alloying and continuous rheo-extrusion

Given limited resources, it is necessary to increase the recycling of wasted aluminum alloy products. Due to the increase in Fe content during recycling, the formation of needle-, lath- and flake-shaped Fe-rich intermetallics reduces the mechanical properties of alloys. In this work, the effects of Cr addition on the microstructural evolution and mechanical properties of as-cast and rheo-extruded Al–1.5Fe (wt%) alloys were investigated. The results indicated that with increasing the Cr content from 0 wt% to 1.2 wt%, the average size of α-Al grains and Al13Fe4 phases first decreased and then increased. When the Cr content was 0.4 wt%, the refined microstructure was obtained; the optimized ultimate tensile strength, yield strength, and elongation of the as-cast alloy were 103.5 MPa, 60.2 MPa, and 36.2%, respectively. In addition, in the as-cast Al–1.5Fe–0.4Cr (wt%) alloy, Cr adsorption on the surface of Al13Fe4 phases was found, which caused the growth inhibition for Al13Fe4 phases. When the Cr content was larger than 0.8 wt%, the formation of coarse Al–Fe–Cr ternary phases resulted in the deterioration of mechanical properties. In order to further tailor the Al13Fe4 phases, the continuous rheo-extrusion of Al–1.5Fe(–0.4Cr) (wt%) alloy was performed. The rheo-extruded Al–1.5Fe–0.4Cr (wt%) alloy exhibited a superior combination of strength and ductility. The strengthening mechanisms induced by Cr addition were discussed. Grain boundary strengthening and dislocation strengthening were responsible for the enhancement in yield strength of the rheo-extruded alloy.

Significant refinement and spheroidization of harmful Fe-rich phases in Al–Cu–Mg alloys by small Sn addition

Solidification phases of conventional cast aerospace Al–Cu–Mg alloys and their evolution during homogenization were comprehensively studied. Significant refinement and spheroidization of solidification phases were found by the addition of 0.04, 0.15, and 1.00 mass % Sn to Al–Cu–Mg alloys. The soluble Sn component is dissolved in the Al matrix as solute atoms, while Sn in excess of the solid solubility segregates in the intradendrites in the form of Sn pools with a size (diameter) of one-half to several micrometers. These solute Sn atoms and Sn pools can capture Cu, Mg, and Fe atoms or hinder their diffusion into the residual liquid phase in the interdendritic region during solidification. Owing to the Sn addition, the contents of the Al2Cu, Al2CuMg, and Al7Cu2Fe phases in the interdendritic region are greatly reduced, thereby leading to significant refinement and spheroidization of these solidification phases. The formation of proeutectoid Mg2Sn phases is also found to be effective for the refinement of solidification phases.

Effect of Ni element deposited at the surface of melt-spun flakes on the microstructure and magnetic performance of hot-deformed Nd-Fe-B magnet

Hot-deformed (HD) Nd-Fe-B magnet prepared from melt-spun flakes features coarse grains (CG) with the average size of 940 nm at the flake boundary. In order to inhibit the growth of CG, metallic Ni has been deposited on the surface of the melt-spun Nd-Fe-B flakes via metallic replacement method. The grain growth at the flake boundary of HD magnets prepared from Ni-deposited melt-spun flakes was investigated. The results show that metallic Ni could be reduced from Ni2+ by Nd-Fe-B flakes via metallic replacement method and deposited on the surface of melt-spun Nd-Fe-B flakes. The introduction of Ni element can inhibit the growth of the CG in HD magnet. The average size of the refined CG is about 200 nm, which is smaller than that (∼260 nm) of single domain grain. Oxygen element was simultaneously introduced into HD magnet via NiO at flake surface, which leads to the oxidation of Nd-rich phase into neodymium oxide at grain boundaries of HD magnet. The coercivity of HD magnets prepared from Ni-deposited melt-spun flakes is determined by the cooperative effect of grain refinement and oxidation of Nd-rich phase.

Synergistic enhancement on mechanical properties and corrosion resistance of biodegradable Mg-Zn-Y alloy via V-microalloying

For the sake of improving the mechanical properties and corrosion resistance of biodegradable Mg alloy synergistically, various content of element V (0, 0.05, 0.10, 0.15, 0.20 wt.%) are introduced into an Mg-Zn-Y alloy with long-period stacking ordered (LPSO) structure, and the effects of V on its microstructure, mechanical properties and corrosion resistance are investigated systematically. The results indicate that the grains are effectively refined by V addition, and the primary α-Mg in Mg-Zn-Y-V0.1 alloy is most significantly refined, with grain size being decreased by 62%. The amount of 18R LPSO structure is increased owing to the V addition. The growth mode of the second phase (W-phase and 18R LPSO structure) is transformed to divorced growth pattern, which ascribes to the thermodynamic drive force of V to promote the nucleation of LPSO phase. Thus, 18R LPSO structure presents a continuous distribution. Due to grains refinement and modification of second phase, the tensile strength and strain of alloys are both enhanced effectively. Especially, the ultimate tensile strength and the elongation of V0.1 alloy are 254 MPa and 15.26%, which are 41% and 61% higher than those of V-free alloy, respectively. Owing to the continuously distributed 18R LPSO structure with refined grains and stable product film, the weight loss and hydrogen evolution corrosion rates of V0.1 alloy are 7.1 and 6.2 mmy−1, respectively, which are 42.6% and 45.4% lower than those of V-free alloy.

Microstructure and Thermal Stability of High‐Temperature Titanium Alloy with Hf Element

The influence of partial substitution of Hf for Zr on the microstructure and thermal stability of near-α high-temperature titanium alloys is systematically investigated. The results show that the addition of Hf promotes the refinement of precipitated phases of the silicides and α2 phase and the (Ti,Zr,Hf)6(Si,Sn)3 S2-type silicides were formed in alloys after aging treatment. During thermal exposure, both silicides and α2 phase in alloy with 2.5 wt% Hf exhibited excellent anti-coarsening ability, which may be attributed to the slow diffusion of Hf in Ti that significantly inhibited the growth rate of the precipitated phase. The loss of plasticity of near-α titanium alloys after thermal exposure is mainly due to the precipitation and coarsening of silicides and α2 phase, therefore, the Hf-containing titanium alloy has more excellent thermal stability, i.e., the plasticity loss rate is decreased from 34.8% (the alloy without Hf) to 7.4% (the alloy with 2.5 wt% Hf).

E2EM's prediction of LaB6 as nucleation substrate for primary Mn-rich phase in Al-Si-Cu-Mn heat-resistant alloy and its refining effect

Edge-to-edge matching (E2EM) model was used to predict the potency of LaB6 as the heterogeneous nucleation substrate for primary Al13Mn4Si8 phase formed during the solidification of Al-Si-Cu-Mn heat-resistant alloy. There are five pairs of orientation relationships (ORs) between LaB6 and Al13Mn4Si8 phases which meet the criteria of E2EM model. One pair of plane ORs ((110)LaB6//(110)Al13Mn4Si8) are demonstrated by TEM observation. This strongly indicates that the LaB6 phase can act as the heterogeneous nucleation substrate for the primary Al13Mn4Si8 phase. 1.0 wt.% of Al-2La-1B master alloy was also added into Al-12Si-4Cu-2Mn alloy to evaluate the refining effect by microstructure observation and tensile test. Experimental results show that addition of Al-2La-1B master alloy can significantly refine the primary Al13Mn4Si8 phase, supporting the prediction accuracy of E2EM model. However, such refinement of primary Al13Mn4Si8 phase does not lead to an improvement in strength. This is due to the larger difference in elastic modulus between the finally formed Al13Mn4Si8 phase and aluminum matrix than that of Al15Mn3Si2 phase.

Microstructural evolution and precipitate behavior of an AZ61 alloy plate processed with ECAP and electropulsing treatment

Electropulsing treatment processing (EPT)-induced microstructural evolution and precipitation behaviour of the β-Mg17Al12 phase in the AZ61 alloy were investigated by using scanning electron microscopy, X-ray diffraction and electron backscattering diffraction patterns. The results revealed that the EPT method is efficient in achieving a near-spherical Mg17Al12 phase (approximately 300 nm) and uniform ultrafine-grained structure (approximately 900 nm) featuring a weakened texture in AZ61 alloy plates after EPT for 40 μs-3 min. The improved structural characteristics are attributed to the rapid recrystallization and grain refinement induced by EPT at lower temperatures and in a short time. On this basis, kinetics analysis of the spheroidization and the dissolution of the β-Mg17Al12 precipitation phase and grain refinement and growth in the samples after EPT were performed. Furthermore, the mechanism of precipitation phase transformation and grain refinement during EPT was discussed.

Effects of Laser Surface Remelting on Microstructure and Corrosion Properties of Mg-12Dy-1.1Ni Alloy

Effects of laser surface remelting (LSR) on microstructure and corrosion properties of as-cast Mg-12Dy-1.1Ni (wt.%) alloy were investigated. The as-cast alloy was mainly composed of α-Mg, lamellar Mg12DyNi phase with an 18R-long period stacking order (LPSO) structure and Mg24Dy5. After LSR treatment, fine and compact 18R-LPSO phase reprecipitated on dendrite boundaries as a continuous network. In addition, the volume fraction of the LPSO phase remarkably increased to 34.9% and the grain size of as-cast alloy was refined to ca. 4 μm. Electrochemical and immersion tests indicated that the LSR-treated alloy exhibited a lower weight loss rate (2.8 ± 0.2 mg/cm2/h) and corrosion current density (160.1 ± 20.7 μA/cm2, and of 37% reduction after LSR) than the as-cast alloy in 0.1 M NaCl solution. The improved corrosion resistance of the LSR alloy was mainly ascribed to the grain refinement and continuous distribution of 18R-LPSO phase on dendrite boundaries.

Effect of various post-extrusion tempering on performance of AA2024 tubes fabricated by shear assisted processing and extrusion

• Extrusion speed of ShAPE for AA2024-T371 billets reaches 7.4 m/min. • The yield strength of the AA2024-T8510 ShAPE-extruded tube is 32% higher than typical ASM and minimum ASTM values. • The elongation at break of ShAPE-extruded AA2024-T8510 tubes is doubled than typical ASM and minimum ASTM values. Aluminum alloy 2024 tubes were extruded using the shear assisted processing and extrusion (ShAPE) method. Extrusions were produced at 7.4 m/min at 482 °C using the ShAPE technique which is more than doubles the previous highest extrusion speed for AA2024 using conventional extrusion methods. Standard T3510 and T8510 post extrusion heat treatments were applied to improve the mechanical performance of ShAPE extruded AA2024 tube. The ultimate tensile and yield strength of the AA2024-T8510 ShAPE-extruded tube are 522.0 ± 3.3 MPa and 510.7 ± 3.3 MPa, which are respectively 18% and 32% higher than typical ASM International and minimum American Society for Testing and Materials (ASTM) values. The elongation at break of ShAPE-extruded AA2024-T8510 tubes is two times higher than the typical ASM International and minimum ASTM values. This improved ductility is attributed to the refinement of grain size and secondary phases as well as the uniform dispersion of sub-micron strengthening precipitates formed during the ShAPE processing.

Effect of process parameters on the microstructure and mechanical properties of bars from Al-Cu-Mg alloy processed by multipass radial-shear rolling

The study of microstructure and mechanical properties formation of A2024 alloy obtained by the multipass radial-shear rolling (RSR) method is discussed in this article. FEM simulation was carried out that made it possible to evaluate the influence degree of rolling temperature–velocity parameters on the strain state of material. It has been found the increase in rotary velocity of rolls significantly influences on the deformation heating of bar after RSR (predominantly in its surface layer). The combination of rolling temperature–velocity conditions at selection of deformation regime has complex effect on structure and properties formation. The analysis of sizes and distribution of phase particles has shown that the rolling at lower temperatures allowed to increase the mechanical strength due to the more intensive refinement of undissolved Fe-containing phase. The gradual decrease in the rolling temperature in each pass makes possible to achieve the high strength (UTS ~ 430 MPa and YS ~ 255 MPa) while maintaining the ductility level ~ 15%, that are comparable to ones obtained at some severe plastic deformation (SPD) methods.

Ultrafine-Grained Microstructures of Al-Cu Alloys with Hypoeutectic and Hypereutectic Composition Produced by Extrusion Combined with Reversible Torsion.

In this study, binary as-cast Al–Cu alloys: Al25Cu (Al–25%Cu) and Al45Cu (Al–45%Cu) (in wt%) were severely plastically deformed by extrusion combined with a reversible torsion (KoBo) method to produce an ultrafine-grained structure (UFG). The binary Al–Cu alloys consist of α-Al and intermetallic Al2Cu phases. The morphology and volume fraction of α-Al and Al2Cu phases depend on the Cu content. The KoBo process was carried out using extrusion ratios of λ = 30 and λ = 98. The effect of phase refinement has been studied by means of scanning electron microscopy with electron backscattering diffraction and scanning transmission electron microscopy. The mechanical properties were assessed using compression tests. Detailed microstructural analysis shows that after the KoBo process, a large number fraction of high-angle boundaries (HABs) and a very fine grain structure (~2–4 μm) in both phases are created. An increase of λ ratio during the KoBo processing leads to a decrease in average grain size of α-Al and Al2Cu phases and an increase in fraction of HABs. UFG microstructure and high fraction of HABs provide the grain boundary sliding mechanism during KoBo deformation. UFG microstructure contributes to the enhanced mechanical properties. Compressive strength (Rc) of Al25Cu alloy increases from 172 to 340 MPa with an increase of λ. Compressive strain (Sc) for Al25Cu alloy increased from 35 to 67% with an increase of λ. High fraction of intermetallic phase in Al45Cu alloy was responsible for room temperature strengthening of alloy and low compressive strain. The deformed Al45Cu alloy with λ = 30 showed that Rc is 194 MPa and Sc is equal to 10%.

Effect of Fabrication Parameter on Microstructure of Mg–5.3 mass%Al–3 mass%Ca for Development of Mg Rechargeable Batteries

Various motor using transportation system in land-sea-air, high speed mobile terminal with 5G specification, and renewable energy storage equipment have required innovative metal rechargeable batteries compared with lithium ones. In particular, magnesium has huge potentialities as an anode material from the standpoint of its theoretical volumetric capacity superior to that of lithium. Secondly, magnesium has been one of the most abundant elements in the Earth’s crust. Moreover, the potential safety by short-circuiting evading with non-dendritic deposition of magnesium. In general, magnesium-based ribbon as an anode has been manufactured by cold rolling which requires multistage process including heat treatment. We have studied rapid liquid quenching process in order to develop low-cost manufacturing technique. On the other hand, we have focused Mg–6 mass%Al–3 mass%Ca alloy due to this unique microstructure which consist of primary crystals and intermetallic compounds along grain boundary. In addition, calcium has affected to prevent of molten magnesium burning in air atmosphere. The structural properties and surface morphology are investigated by XRD and Digital Microscope, respectively. Microstructure has been observed by FE-SEM and FE-TEM. Moreover, these electrochemical properties have been examined by constant current charge - discharge tests using 3 electrodes type cell. Mg–3 mass%Al–1 mass%Zn alloy cold rolled thin plate has been investigated as comparison. The ribbons that exhibited electrochemical properties had a fine microstructure. It is suggested that the grain refinement and dispersion of the second phase are important to improve the charge-discharge properties of Mg–Al–Ca based anode materials.

The effects of Nb addition on magnetic property of Nd10.23Pr2.56Fe68.32Co13.08B5.81 ribbons through modification of the intergranular phase and grain refinement

The (Nd10.23Pr2.56Fe68.32Co13.08B5.81)100-xNbx (x = 0, 0.5, 1, 2, 3) ribbons were prepared by melt-spinning at a wheel speed of 15 m/s. The effects of Nb addition on the microstructure and the magnetic properties of the ribbons were investigated. The X-ray diffraction (XRD) patterns of the ribbons show that the Nd2(Fe, Co)14B (2:14:1) phase is observed in all samples indicating that Nb addition does not change the phase constitution. The transmission electron microscopy (TEM) images show that Nb addition can dramatically reduce the average grain size from 52 ± 5 nm of the Nb-free alloy to 12 ± 2 nm of the Nb-containing x = 3 alloy. Based on the atom probe tomography (APT) result, we identify different mechanisms for grain refinement at different Nb content. When x = 0.5, the distribution of Nb is uniform at the intergranular phase and Nb addition promotes the segregation of rare-earth Nd and Pr at the thick ferromagnetic intergranular phase (≈ 10 nm), which leads to decreasing the average grain size to 38 nm. With further increasing Nb addition to x = 2, the existence of Nb-rich precipitations (2–4 nm in width) at the grain boundaries effectively reduces the grain size to 16 nm. The remanence (Br) and the maximum energy product ((BH)max) are obviously increased by Nb addition and the maximum of the Br and the (BH)max is obtained in the (Nd10.23Pr2.56Fe68.32Co13.08B5.81)98Nb2 (x = 2) alloy. The values of the Br and the (BH)max are 0.90 T and 138 kJ/m3, 8.4% and 22.1% higher than that of the Nb-free alloy. It ascribes to the grain refinement, the changes of the distribution and the composition of the ferromagnetic intergranular phase by Nb addition. Our findings provide a new method of designing prospective permanent alloys with increased magnetic properties by reducing the grain size and tuning the distribution and chemical composition of the intergranular phase.

Comparative Study on the Effect of Ultrasonic Power on the Microstructure and Mechanical Properties of 2195 Aluminum Alloy Ingot

High-intensity ultrasound was introduced for the casting of 2195 aluminum–lithium alloy ingots. The shape of the ingots was a cylinder with a length of 650 mm and a radius of 30 mm. In this study, the effects of different ultrasonic powers were applied in the melt. The grain shape, α-Al grain size, the size of the precipitated phase, and the mechanical properties of the ingots were compared. The results showed that when the power of the ultrasonic system was maintained at 1,600 W, an ingot with a more uniformly dispersed precipitation phase and grain refinement structure was formed. It can be concluded that the coarse eutectic structure in the ingot is effectively reduced when the power is around 1,600 W, and the mechanical properties of the ingot reach the best value.