Effect Of Grain Refinement Research Articles

Effect of grain boundary engineering on grain boundary character distribution and deformation behavior of a TRIP-assisted high-entropy alloy

This study carried out two-step thermo-mechanical processing (TMP) in grain boundary engineering (GBE) to optimize the grain boundary character distribution (GBCD) and tensile properties of a transformation-induced plasticity-assisted high-entropy alloy (TRIP-HEA). The evolution and mechanism of GBCD in the HEA were characterized and discussed using electron backscatter diffraction (EBSD). The tensile properties of the HEA after undergoing different TMPs were evaluated through room-temperature uniaxial tensile tests, and the influence of GBE on the deformation mechanisms was investigated using techniques such as EBSD and transmission electron microscopy (TEM). The results indicated that the fraction of low Σ coincident site lattice (CSL, Σ ≤ 29) boundaries exhibited a decreasing trend followed by an increasing trend with an increase of second-step cold rolling strain during TMPs, and the overall fraction of Ʃ9 + Ʃ27 boundaries showed an increasing trend. When the reduction ratio was 10%, the low-ƩCSL boundaries fraction reached ~66.35%. In terms of tensile properties, all GBE specimens showed improvement in strength and ductility. When the reduction ratio of second-step cold rolling was 20%, the yield strength was 506.7 MPa, which was ~59% higher than base material (BM) sample. The ultimate tensile strength was 885.6 MPa, ~26% greater than BM sample. In addition, when the reduction ratio of second-step cold rolling was 3%, the total elongation was 52.6%. The main deformation mechanisms of the HEA were dislocation slip, stacking fault (SF), nano-twining, and phase transformation. The optimization of GBCD had multiple effects on the deformation mechanisms. It manifests in several ways, such as the enhancement of strain uniformity through ΣCSL grain boundaries, improving the ability of dislocation multiplication and stress-induced cracking resistance, as well as the strengthening due to the combined effects of phase transformation and grain refinement.

Laser-directed energy deposition of ZrH2 particles reinforced Al7075 alloy: Cracks elimination and strength enhancement

Metal-based laser additive manufacturing, particularly Laser-Directed Energy Deposition (LDED), holds great promise for producing high-strength aluminum alloy components used in industries such as automotive manufacturing, aerospace, and biomedicine. However, achieving defect-free and superior mechanical strength in high-strength aluminum alloys, especially 7XXX series Al alloys, through LDED remains challenging. In this study, the LDED of ZrH2 particles reinforced Al7075 alloy was investigated. Results indicated that the addition of ZrH2 particles to the Al7075 alloy facilitated the columnar-to-equiaxed transition and effectively prevented hot-crack formation during the solidification process, leading to a crack-free and fine equiaxed-grain microstructure. The as-deposited Zr-modified Al7075 alloy demonstrated a favorable combination of strength and ductility, a yield strength of 266 MPa, a strength of 321 MPa, and an elongation of 21.0% in the Al7075–3%ZrH2 sample, which represents promising performance among the reported LDED-fabricated Al alloys. Contributions of four different strengthening mechanisms to yield strength were calculated, showing that the introduction of ZrH2 particles highlighted the effects of grain refinement and geometrically necessary dislocation strengthening. Moreover, the grain reinforcement mechanism in the Al7075 alloy with ZrH2 particles reinforced was elucidated after adequate material characterizations including SEM, EDS, TEM, and XRD. Needle-like Al3Zr and angular-like Al3Zr were observed in the equiaxed and ultrafine grain regions of the LDED-fabricated Al7075–3%ZrH2 samples, corroborating the truth that Al3Zr serves as heterogeneous nucleation sites during the solidification and plays a significant role in grain refinement. The successful manufacturing of crack-free, equiaxed high-strength 7XXX series Al alloys lays the foundation for LDED production of high-strength aluminum engineering components.

The microstructural features and strain recovery characteristics of Ti–V–Al shape memory alloy with minor Sc addition

In the present work, minor Sc addition was employed to control the microstructural features, further optimizing the mechanical/functional performances of Ti–V–Al based shape memory alloy. The results revealed that phase constituents of Ti–V–Al based shape memory alloys were dominated by single αˊˊ martensite phase, regardless of Sc content. Nevertheless, Sc addition caused the significant lattice distortion of Ti–V–Al based shape memory alloy. Meanwhile, the grain size of Ti–V–Al based shape memory alloys were reduced due to Sc addition. Besides, the martensite morphologies evolved from self-accommodation configuration to optimal orientation configuration, but the types of twins kept unchanged. All Ti–V–Al based shape memory alloys showed the reversible αˊˊ→β martensitic transformation in heating curves, irrespective of Sc content. With Sc content increasing, the martensitic transformation temperatures increased linearly due to the chemical composition effect and mechanical effect. Moderate Sc addition was favor to the improvement of thermal cycling stability of Ti–V–Al based shape memory alloys, which can enhance its functional stability. In proportion, the mechanical and functional properties of Ti–V–Al based shape memory alloys firstly increased and then decreased. Ti–V–Al based shape memory alloy with moderate Sc content of 0.025 at.% possess the higher fracture strength of 748.4 MPa, superior ductility of 18.7% and the larger shape memory effect strain of 4.31% under the 8% pre-strain condition. The higher performances in Ti–V–Al shape memory alloy with 0.025 at.% Sc can be attributed to the compressive effect of solution strengthening and grain refinement.

Calculation of the effective thermal conductivity of porous polycrystalline U-10Mo alloy based on phase-field simulation

In the present work, the thermal conductivity of U-10Mo was calculated, considering the effects of different microstructures, including fission bubbles and recrystallization, through simulations using the phase-field method. The concept of effective thermal conductivity was used to describe thermal conductivity. Systematic calculation was conducted to determine the effect of fission bubble porosity on thermal conductivity. A shape factor was proposed to quantitatively represent the different shapes of bubbles, and the specific expression was also given. It was found that the shape factor had a significant impact on thermal conductivity. Additionally, the effects of grain refinement and coupled bubble evolution with different fission densities on thermal conductivity had been quantitatively studied. The calculated results were in good agreement with the experimental results. It was revealed that recrystallization had a significant impact on thermal conductivity, with higher irradiation density resulting in lower thermal conductivity due to the higher GB density and larger porosity. Based on the models presented in this paper, it is of great engineering significance to predict the thermal conductivity changes of U-10Mo fuel in service.

Simultaneous regulation of strength and ductility of laser powder bed fusion manufactured Haynes 230 alloy

Haynes 230 alloy is widely used in aero-engines with high strength, fatigue resistance, oxidation resistance and other properties. However, the powder metallurgy process limits its application due to hot cracks and low strength. In this work, crack inhibition and mechanical properties improvement of the laser powder bed fusion (L-PBF) manufactured Haynes 230 alloy using 25 groups of different laser energy densities and scanning strategies were investigated. Results show that the high density, nearly crack-free, fine microstructure, and excellent strength and ductility were achieved by a laser energy density of 59.4 J/mm3 and rotation angle of 90° for the L-PBF manufactured Haynes 230 alloy. The microstructure was composed of γ matrix, carbides (M6C, M23C6), and La2O3 nanoparticles. Interestingly, many carbides were found to be mainly uniformly distributed at the grain or sub-grain boundaries with the following orientation relation: [011]γ//[011]M23C6. Simultaneously, by adjusting laser energy density and scanning strategy, the liquid film, low-melting eutectic phase, hot stress concentration, and high-angle grain boundaries (HAGBs) were suppressed, and the hot cracks were reduced. In addition, yield strength and ultimate tensile strength enhancement of the L-PBF manufactured Haynes 230 alloy was attributed to the synergistic effect of solid solution strengthening, dislocation strengthening, Orowan strengthening, and grain refinement. Whereas ductility enhancement was the main effect of defect inhibition, grain refinement, and nanoprecipitate. This work has verified the feasibility of crack inhibition and mechanical properties improvement of the L-PBF manufactured Haynes 230 alloy by various laser energy densities and scanning strategies.

The effect of laser shock peening on very high cycle fatigue properties of laser welded 2A60 aluminum alloy joints

Laser shock peening (LSP) technology has the advantages of deep residual compressive stress field, low degree of cold hardening and controllable hardening area. The surface modification of welded structures has broad prospects. To predict the very high cycle fatigue (VHCF) life of an aero engine impeller, it is of great engineering significance to study the VHCF performance of 2A60 aluminum alloy. The effects of LSP on VHCF properties of laser welded joints were investigated from the S-N curve, fracture morphology, residual stress, hardness, and roughness. The results show that the S-N curves of the 2A60 aluminum alloy matrix under the condition of ethanol cooling belong to the infinite life type. The S-N curves of welded and LSP samples belong to the continuous decline type. In the process of LSP, the fatigue crack source is transferred from the surface of the sample to the second surface of the sample, which not only counteracts the residual tensile stress introduced on the surface of the sample during welding but also introduces considerable residual compressive stress on the surface of the sample. The roughness is reduced, thus improving the fatigue stsample's fatigue strength and life. The strengthening mechanism of LSP is discussed from two aspects of dislocation strengthening and residual stress. The LSP results in many dislocation proliferation within the grain, and the dislocation entanglement and dislocation wall are formed among the dislocations. The original coarse crystal is divided into multiple subgrains to achieve the effect of grain refinement. Grain refinement and high-density dislocation increase the hardness of the material.

Grain-refining effects and mechanism of novel Al-Nb-B refiner on Al-Mg-Si alloy: phase-field simulation and experiment study

In this paper, the grain-refining effect of Al-Nb-B refiner in wrought Al alloys and corresponding refining mechanism was investigated using phase-field simulation and experiment methods. Through experimental statistics and data correction, the seed radius introduced by Al-Nb-B refiner into Al alloy melt and the corresponding quantitative density distribution data were obtained, and a seed density model (SDM) model has been established. On this basis, a multi-phase field method (MPFM) combined with the calculation of phase diagram (CALPHAD) has been employed to simulate the α-Al grain evolution of Al-Mg-Si alloy during the solidification process with the help of thermodynamic database. Experimental studies showed that the addition of 0.03 wt% Nb (Adding by Al-1.93Nb-0.22B master alloy) significantly reduced the grain size from 956.4 μm to about 219.4 μm, and the grain size slowly decreased to 192.3 μm by continuing to add refiner to 0.09 wt% Nb. Meanwhile, the simulation results demonstrated that after the addition of refiners, dendrite morphology transformed from the relatively developed dendrites with secondary and tertiary dendrites to a fine and uniform equiaxed shape. Simulation and experimental studies showed quantitative agreement. In addition, the results also prove that the addition of Al-Nb-B refiner can provide high-quality and stable heterogeneous nucleation particles.

A modified dislocation density-based model of 30CrMnSiA considering the coupling effect of electroplasticity and grain refinement during the pulsed current-assisted plane strain deformation

A modified dislocation density-based model of 30CrMnSiA considering the coupling effect of electroplasticity and grain refinement during the pulsed current-assisted plane strain deformation

Study on the FeCoCrNiMnTix High Entropy Alloys Fabricated by Laser Cladding

Because of the high entropy effect, a simple solid solution structure can be obtained in high entropy alloys (HEAs), giving the HEAs greater overall properties than conventional alloys. Cladding layers of FeCoCrNiMnTix HEAs were prepared on Q355 steel by laser cladding technology. X-ray diffraction (XRD), metallographic microscope (OM), and scanning electron microscope (SEM) were used to examine the microstructure of the cladding layers. The microhardness and wear resistance were tested using a Vickers microhardness tester and wear testing machine, respectively. The FeCoCrNiMn HEAs consisted of a face-centered cubic (FCC) solid solution. The addition of Ti promoted the formation of body-centered cubic (BCC) and hexagonal solid solution. When Ti content was higher than x=0.8, the Laves phase formed. The addition of Ti increased the microhardness of the FeCoCrNiMnTix (x=0.5, 0.6, 0.8, 1.0) HEAs, which is due to the effect of solution strengthening, microstructure strengthening, and grain refinement. When Ti content was less than x=0.6, the alloy’s wear resistance was positively correlated with its hardness, and the Ti0.6 alloy had the best wear resistance. However, as Ti content exceeded x=0.6, the brittle and hard Laves phase formed, which resulted in reduced wear resistance.

Effect of sub-solvus treatment on discontinuous precipitation behavior and mechanical properties of AlCrFeNiV multi-principal element alloy

The discontinuous precipitation (DP) behavior of AlCrFeNiV multi-principal element alloys (MPEAs) based on initial face-centered-cubic (FCC) single-phase structure is investigated in this work. The investigation focuses on the impact of a novel sub-solvus (SS) treatment, which accelerates the DP transformation kinetics by refining the microstructure, as compared to the conventional total-solution (TS) treatment. This acceleration is attributed to an increase in nucleation sites or localized changes in chemical composition. The presence of NiAl phases with a B2 structure, which precipitate along prior grain boundaries, is believed to play a dominant role in grain refinement. Additionally, highly dispersed L12 nano-precipitates are observed within the FCC matrix in both TS- and SS-treated samples. Building upon the strengthening effect of L12 nanoprecipitates, further optimization strategies are explored through variations in isothermal aging treatments. This leads to the preparation of DP structures with various degrees and morphologies, consisting of BCC phases and a coherent FCC/L12 microstructure. The additional HDI hardening stemming from the resulting DP/non-DP heterogeneous structure and the spheroidization of the ultrafine DP lamellar structure allowed the alloy to exhibit excellent mechanical properties, the latter of which yielded an interesting combination of strength (1907 MPa tensile strength, 1694 MPa yield strength) and ductility (10.1% elongation). These findings highlight the effect of the prior grain refinement on the DP transition kinetics, BCC lamellae stability, and the overall mechanical performance of AlCrFeNiV multi-principal element alloys (MPEAs).

Effect of Y content on the microstructure and mechanical anisotropy of Mg–6Zn-xY-0.5Ce-0.4Zr alloy subjected to asymmetric rolling

An in-depth study of the anisotropic mechanical behavior of Mg alloys is essential for optimizing mechanical properties, designing high-performance Mg alloys, and developing processing processes. This work investigates the microstructure and mechanical anisotropy of Mg–6Zn-xY-0.5Ce-0.4Zr (MZCZ-xY) alloys with varying Y contents subjected to asynchronous rolling (ASR). The Y content significantly affects the microstructure and mechanical anisotropy of the MZCZ-xY alloy. In lower Y content alloys (MZCZ-0.2Y, MZCZ-0.5Y), the second phase mainly consists of Mg3Zn6Y (I phase) and Mg1.5Zn9.5Ce3, while the addition of 1.0 wt% Y leads to the appearance of Mg3Zn3Y2 (W phase) in the alloy. Furthermore, increasing Y content results in grain growth in the as-cast state, which will affect the average grain size after asymmetric rolling (ASR) deformation. However, alloys with higher Y content exhibit a more pronounced effect of grain refinement at the same ASR strain. Moreover, increasing Y content promotes the activation of tensile twins, with higher Y content leading to greater tensile twin activation after ASR treatment. The MZCZ-0.2Y alloy shows lower mechanical anisotropy, which is closely related to the homogeneous texture component and uniform Schmid factor (SF) in each loading direction. Therefore, the regulation of mechanical anisotropy in Mg alloys can be achieved by obtaining uniform texture components and uniform SF in each loading direction.

Effect of Al5Ti1B and Al8B on the microstructure, wear and corrosion behavior of CuZn19Al6 bronze alloy

In this study, the effects of Al5Ti1B and Al8B grain refiners added to CuZn19Al6 manganese bronze alloy used in the aviation industry on the microstructure, mechanical properties and corrosion resistance of the alloy were investigated. Al5Ti1B grain refiner reduces the grain size of the alloy by ∼49%, while Al8B grain refiner is more limited. As a result of the addition of Al5Ti1B, an increase in hardness was observed due to the decrease in grain size, while it was determined that the Al8B grain refiner can be dissolved in the alloy and might be increased the hardness with secondary phases. It has been observed that the addition of both grain refiner increases the wear resistance while decreasing the friction coefficient of the alloy. However, no linear change was observed in both the friction coefficient and the wear rate depending on the wear test parameters. According to the potentiodynamic polarization and EIS impedance measurement results, the decrease in grain size with the addition of Al5Ti1B increased the corrosion resistance of the alloy. However, the addition of Al8B master alloy reduced the corrosion resistance of the alloy.

Effect of Synchronized Laser Shock Peening on Decreasing Defects and Improving Microstructures of Ti-6Al-4V Laser Joint.

Repairing processing is a significant method for damaged high-cost Ti-6Al-4V components to decrease economic loss, which usually utilizes a welding technique. For a large-size structural component, welding processing is commonly completed in air conditioning, which makes it difficult to avoid welding defects. To this end, an appropriate matching technique is important for improving welding performance. In the present research, asynchronized laser shock peening (ALSP) and synchronized laser shock peening (SLSP) techniques were utilized to decrease the influence of macro welding defects on laser-welded Ti-6Al-4V joints. The results show that SLSP has a greater effect on inducing surface plastic deformation on Ti-6Al-4V joints with a pitting depth of more than 25 microns while ALSP can lead to a pitting depth of about 15 microns. Through micro-CT observation a long hot crack exists in the central area of as-welded joints with a length of about 2.24 mm, accompanied by lots of pores in different sizes on double sides. After ALSP processing, some pores are eliminated while others are enlarged, and one-side crack tips present closure morphology. However, some microcracks exist on the side-wall of hot cracks. With the influence of SLSP, significant shrinkage of pores can be observed and both sides of crack tips tend to be closed, which presents a better effect than ALSP processing. Moreover, greater effects of grain refinement and thermal stress release could be achieved by SLSP processing than ALSP, which can be ascribed to dynamic recrystallization. For the as-welded joint, the ultimate tensile strength (UTS) and elongation (EL) values are 418 MPa and 0.73%, respectively. The values of UTS and EL in the ALSP processed joint are increased to 437 MPa and 1.07%, which are 4.55% and 46.48% higher than the as-welded joint, respectively. Such values after SLSP processing are 498 MPa and 1.23%, which are 19.14% and 68.49% higher than the as-welded joint, respectively.

Effect of ultrasonic impact peening on stress corrosion cracking resistance of austenitic stainless-steel welds for nuclear canister applications

In nuclear applications, the utilization of austenitic-based stainless steel (ASS) components is an ideal material choice for storing spent nuclear fuels in dry storage canisters (DSC). However, due to the chloride rich environments in which they operate, failure in the form of stress corrosion cracking (SCC) frequently occurs. The following study assesses the efficacy of ultrasonic impact peening (UIP) on SCC susceptibility of gas tungsten arc welded (GTAW) stainless steel (SS) components, with an aim to control the SCC failure. The UIP induces residual compressive stresses (RCS) and a severely plastically deformed (SPD) layer containing nanograins on the surface. The superior SCC resistance of UIP'ed specimens is due to the synergistic effect of grain refinement and RCS. The underlying mechanisms for these findings were elucidated based on the modification of microstructural features and mechanical properties. These findings demonstrate that UIP is a potential technique for DSC application to mitigate the SCC susceptibility of ASS weld joints.

High-cycle fatigue enhancement of dissimilar 2017A-T451/7075-T651 Al alloy joint fabricated by a single pass FSW without any post-processing

This study investigates the microstructural, mechanical, high-cycle fatigue, and fracture behaviour of a dissimilar 2017A-T451/7075-T651 Al alloy joint produced by single-pass friction stir welding (FSW) without post-processing. Residual stress analysis revealed low tensile residual stresses in the longitudinal direction on the crown side and compressive residual stress in the transverse direction and on the root side of the weld, indicating an almost zero-stress state. High-cycle fatigue tests showed the superior fatigue endurance of the FSWed sample due to the synergistic effect of expressive grain refinement and compressive residual stress in the transverse direction. Fractographic observations confirmed a brittle type II failure with low fracture toughness in the base material 7075-T651 alloy. In contrast, both the FSWed samples and the base 2017A-T451 alloy displayed a ductile transition with type I failure, resulting in higher average fracture toughness values. The direction and propagation of the fatigue crack in the FSWed sample were influenced by the microstructure, with the crack completely bypassing the stir region consisting of larger crystal grains that acted as the crack arrester. This study highlights the high potential of single-pass FSW technology for producing thick dissimilar Al alloy joints with enhanced high-cycle fatigue life without requiring post-treatment. The findings of this study can benefit industries that require high-performance lightweight structures with improved fatigue life, such as aerospace and transportation.

Effects of multiple laser shock peening impacts on microstructure and wear performance of wire-based laser directed energy deposition 17-4PH stainless steel

As an advanced surface-strengthening technology, laser shock peening (LSP) is suitable for strengthening high-energy beam additive manufacturing components by improving the uneven temperature distribution and mechanical anisotropy problems. The present study investigated the influence of multiple LSP impacts on the microstructure evolution and wear performance of wire-based laser directed energy deposition (LDED) 17-4 PH stainless steel. Results showed that with the increase of LSP impacts, the average grain size of the wire-based LDED layer decreases and the dislocation density increases. Meanwhile, the residual stress was completely converted from tensile state to compressive state, and reaches the maximum value of 424 ± 15 MPa. In addition, the significant improvement of microhardness and wear resistance after 3 LSP impacts is attributed to the combined effects of grain refinement and dislocation strengthening.

The hot deformation behavior, microstructure and texture evolution of homogenized Mg–9Li–1Zn alloy

In this study, the hot deformation behavior, microstructure and texture evolution of Mg–9Li–1Zn (LZ91) alloy were investigated systematically, and the best Arrhenius hot deformation constitutive equation model and processing map of the LZ91 alloy were developed. Hot compression tests were performed at deformation temperatures and strain rates ranging from 175 °C to 275 °C and 0.001 s−1 to 1 s−1, respectively. The results showed that Arrhenius constitutive equation can predict accurately the hot deformation behavior of LZ91 alloy. The instability areas for this alloy were concentrated in the range of 175 °C–220 °C, 0.01 s−1–0.1 s−1 and 225 °C–260 °C, 0.001 s−1–0.002 s−1 and 0.02 s−1–1 s−1. The observation of microstructure revealed that the alloy is deformed by the cooperation of the basal slip system and the pyramidal conical slip system. In addition, the hardness which increases in a gradient from the center to the edges is the result of the combined effect of grain refinement and texture.

Ultraviolet picosecond ultrashort pulsed laser micro glazed EB-PVD YSZ coatings for improving the molten salt (Na2SO4 + V2O5) corrosion resistance

In this study, yttria-stabilized zirconia was glazed for the first time using an ultraviolet picosecond ultrashort pulse laser (laser micro glazing, LMG). A smooth LMGed layer (surface roughness: ∼1.4 μm) with extremely narrow cracks (width: < 0.6 μm) was fabricated on the surface to resist molten salt corrosion. The hot corrosion resistance of LMGed coatings was systematically investigated. Two models of corrosion behavior were observed from the results: (І) widespread but slow corrosion of columnar crystals, and (II) rapid but little penetration in defects (inter-columnar gaps, and cracks). The thermal stabilization of the LMGed layer was greatly improved due to the positive effects of grain refinement on elevating oxygen vacancies and more uniform redistribution of Y3+. The content of YVO4 and m-ZrO2 on the LMGed coatings was significantly reduced compared to the non-LMGed coatings. The self-healing of narrow cracks under prolonged high temperatures resulted in slow and slight penetration of the molten salt along the grain boundaries. No visible grey YVO4 was observed throughout the interior, demonstrating the positive role of LMG technology in enhancing hot corrosion resistance.

Influence of Tungsten Addition on Microstructure and Tensile Properties of Ti6Al4V Fabricated by Laser-Directed Energy Deposition

The addition of tungsten can improve the high-temperature oxidation resistance of titanium alloys. However, as its applications continue to expand, new demands are being placed on its room temperature strength. Here, we provide a dense titanium alloy with high strength by introducing proper W powders into the Ti6Al4V powders under direct energy deposition. The effect of tungsten addition on the microstructure and tensile properties of the Ti6Al4V alloy was investigated. Compared to pure Ti6Al4V, the titanium alloy with tungsten addition exhibited refined α′ martensite and β grains, which is attributable to the effect of tungsten on the structural subcooling of titanium and on the formation temperature of the α′ martensite. Owing to the synergistic strengthening effects of grain refinement and solid solution strengthening, the W-containing alloy shows a high tensile strength of 1333 MPa and yield strength of 1219 MPa, which are significantly higher than Ti6Al4V alloy’s tensile strength of 940 MPa and yield strength of 860 MPa. This approach provides a pathway for design and preparation of high-strength titanium alloys by additive manufacturing.

Coupling effects of SiC and TiB2 particles on crack inhibition in Al-Zn-Mg-Cu alloy produced by laser powder bed fusion

A novel Al-Zn-Mg-Cu alloy free of cracks was produced utilizing laser powder bed fusion (LPBF) and modified with SiC and TiB2 particles. The interdependent effects of SiC and TiB2 particles on morphology, microstructure, and crystallographic texture were examined. The mechanisms behind phase evolution and crack inhibition were elucidated. The results show that a nearly dense Al-Zn-Mg-Cu alloy could be obtained when the mass fraction of SiC and TiB2 particles was 4%. TiB2 particles remained stable and acted as nucleation agents in the molten pool. Partial SiC particles reacted with the Al matrix to form rod-like Al4C3, lamellate Al4SiC4, and flocculent Si phases, which provided nucleation agents and liquid replenishment for matrix grains. The columnar grains of the matrix were refined into equiaxed grains, and the average size decreased from 37.15 μm to 7.54 μm. The preferential growth of grains along the (001) 〈001〉 direction was suppressed and transformed into a disordered random growth. The innovative Al-Zn-Mg-Cu alloy demonstrated an ultimate tensile strength of 492±12 MPa and an elongation of 7.2%±0.7%. The microhardness was enhanced, and the microhardness heterogeneity was reduced. The solidification properties were regulated, the temperature interval between solidus and liquidus was narrowed, and the liquidity of the molten pool was improved. The hot cracking of Al-Zn-Mg-Cu alloy was inhibited due to the interdependent effects of grain refinement by TiB2 particles and sufficient liquid metal replenishment by SiC particles.