High Strain Rate Range Research Articles

Dynamic deformation behavior of Fe-0.22C-1.65Si-1.98Mn quenching and partitioning steel over a wide range of strain rates and constitutive model establishment

During traffic accidents, automobiles often experience rapid deformation at high strain rates spanning from 10² to 10³ s⁻¹. The dynamic deformation behavior and the constitutive model of the materials are crucial for precisely analyzing and simulating vehicle collisions and damage. This study focuses on a high-strength quenching-partitioning steel (Q&P steel) compositionally tailored for automotive applications, specifically Fe-0.22C-1.65Si-1.98Mn. Tensile tests were conducted under quasi-static (10⁻⁴–10⁻¹ s⁻¹) and dynamic (1–10³ s⁻¹) conditions to obtain stress-strain data, based on which the deformation behavior and instability mechanism of the Q&P steel were revealed. A Johnson-Cook (J-C) constitutive model was established to predict the stress-strain behavior. This model was further improved by incorporating the nonlinear influence of strain rate on stress, resulting in a significant reduction of prediction error by 60.9 % in the high strain rate range. Based on the modified J-C model, the finite element simulations of the high-speed collision for U-shaped and tubular components were conducted. The simulations exhibit excellent agreement with experimental results, thus confirming the accuracy of the model in predicting high-speed deformation behavior of the Q&P steel. This validation enables precise simulations of dynamic collision characteristics and energy absorption.

Micromechanical response of an electrodeposited NiP metallic glass by pillar compression under extreme conditions

In this work, the mechanical properties of pulse electrodeposited amorphous nickel phosphorous (NiP), with ∼16 wt% P, was investigated for an improved understanding of the deformation behavior of metallic glasses at extreme conditions, particularly at the microscale. Upon decreasing the temperature to sub-ambient, both the yield strength and the shear band density increase. While the change of yield strength with temperature can be well explained by a cooperative shear model, the increase in the number of shear bands can be related to an increase in potential sites for activation of shear transformation zones due to the enhanced structural heterogeneity at lower temperatures. This, however, hinders the percolation of deformation units and leads to a decrease in the shear band propagation speed, from ∼50 nm/s at 295 K to ∼20 nm/s at 195 K. By testing micropillars across seven orders of magnitude in strain rate, a two-stage strain rate sensitivity is observed, from nearly negligible at the quasi-static range (m1 = 0.001 ± 0.002 for 10−3 s−1 to 10−1 s−1) to highly positive at dynamic high strain rate range (m2 = 0.02 ± 0.004 for 1 s−1 to 1000 s−1). This transition implies a change in the yield-controlling process, from the diffusion-assisted relaxation at quasi-static conditions to the rate of energy barrier crossing of shear transformation zones at high strain rates. These findings highlight several distinctive features of microscale metallic glasses, including the reduced shear band velocity at sub-ambient temperature and the two-stage strain rate sensitivity.

Behaviour of glued-laminated timber beams under impact loading

Short duration loads, such as impact loading, have the potential to generate catastrophic effects on infrastructure and loss of life. Although design provisions for engineered wood products are included in Canada’s blast design standard, CSA S850, how these structural materials respond to blast and impact loads across a wide range of high strain rates has not been well documented. An experimental program was carried out using a newly established Drop Weight Impact Testing Facility to investigate the flexural behaviour of glued-laminated timber beams subjected to impact loading. High strain rates were generated, whereby the dynamic specimens were found to differ quantitatively and qualitatively from their quasi-static counterparts. Dynamic increase factors of 1.13 and 1.20 were observed on the peak resistance and initial stiffness, respectively. A single-degree-of-freedom model was developed and validated against the experimental test results, where it was found to accurately predict the displacement–time histories of the specimens until failure.

Dynamic mechanical properties and constitutive model establishment of QSTE420 steel

The uniaxial tensile tests of QSTE420 steel under different strain rates were carried out using an electronic universal material testing machine, a high-speed tensile testing machine and a split Hopkinson tension bar (SHTB) device, the engineering stress-strain curves of steel within the range of 0.001– 1000 s−1 were obtained and the mechanical properties of steel at different strain rates were analyzed. The results show that in the static strain rate range of 10−3– 10−2 s−1, the yield strength and tensile strength of QSTE420 steel exhibit minimal variation, fluctuating between 430– 434 MPa and 507– 515 MPa, respectively; while the uniform elongation and elongation at break remain approximately at 12% and 35%, respectively. In the high strain rate range of 10−1– 103 s−1, both yield strength and tensile strength exhibit a consistent increase in direct correlation with the tensile rate. Specifically, the yield strength increases from 444 to 607 MPa and the tensile strength increases from 523 to 640 MPa as the strain rate escalates from 10−1 to 103 s−1. Moreover, the elongation at break demonstrates a general increasing trend and reaches its peak value of 45.65% at 100 s−1. The morphology of fracture surfaces under different strain rates are observed by Scanning Electron Microscopy (SEM). The fracture appearance analysis reveals numerous dimples in the fracture, indicating a ductile fracture. Furthermore, the comparison demonstrates that steel exhibits enhanced plasticity at a strain rate of 100 s−1. Based on the experimental results, the Johnson-Cook constitutive model was established and modified. The modified Johnson-Cook model exhibits a higher determination coefficient (R2) compared to the original version, signifying an improved fitting accuracy.

Strengthening mechanisms and microstructural evolution of medium manganese steel under dynamic and static loading

The study analyzes the deformation strengthening mechanisms of medium manganese steel under dynamic and static loading conditions. Different austenite volume fractions (7.4 %, 19.1 %, 30.9 %, 37.7 %) were obtained by varying the heat treatment temperatures (640 °C, 660°C, 680 °C, 700 °C). Results show a linear increase in austenite volume fraction with higher annealing temperature, while carbon content in austenite decreases. Yield strength initially decreases and then increases with annealing temperature. The mechanical properties of all four temperature-tested steels show a clear strain rate dependence in the high strain rate range, with strength increasing with strain rate. Quasi-static conditions no significant strain rate sensitivity. 680 °C test steel's quasi-static deformation is mainly governed by the transformation-induced plasticity (TRIP) effect and dislocation slip in body-centered cubic (bcc) crystals. Dynamic deformation after a strain of 0.14 shows a weakened TRIP effect, and dislocation strengthening in bcc crystals becomes dominant despite a large amount of untransformed austenite. During quasi-static deformation, 700 ℃ test steel exhibits strain hardening due to the TRIP effect at low strains and significant dislocation strengthening in bcc crystals at high strains. Although the TIRP effect is initially suppressed during dynamic deformation, it lasts for a long time. The combined effects of the TRIP effect and martensite dislocation strengthening determine the deformation strengthening mechanisms. Additionally, an optimized Voce model with strain rate strengthening term is proposed. It can well describe the mechanical behavior under dynamic strain rate.

Hot Deformation Behavior of 301L Stainless Steel and Dissolution Behavior of δ‐Ferrite During Heat Treatment

The hot deformation behavior of 301 L stainless steel is investigated at 1000–1250 °C and 0.1–50 s−1. Deformation characteristics are studied through compressive stress–strain curves and constitutive equations. According to the dynamic material model and a series of diffusion annealing experiments, the hot processing map of 301 L stainless steel is established to determine the suitable processing domain. The results show that the stable domain is located in 1085–1240 °C and high strain rate range of 4.5–50 s−1, and the strain rate is the main factor affecting the machinability. Based on the hot compression tests, δ‐ferrite gradually forms a network structure with the increase of temperature; however, it can be inhibited at high strain rate. Therefore, it is necessary to reduce the temperature and increase the strain rate in the actual processing of the machinable area. It is found that diffusion annealing can reduce the content of δ‐ferrite from 12% to 0.67%, and the dissolution of δ‐ferrite is controlled by the diffusion of Cr and Ni, especially noticeable at the interface between γ and δ phase. Finally, the optimum diffusion annealing process parameter is determined at 1300 °C and 10 min.

Numerical Simulation of the Taylor Impact Test for Laser Powder Bed Fusion Parts Based on Microstructural Internal State Variables

The response of any engineering design components to stresses should be predictable, While the response of a material to complex loading, such as high strain rates experienced during service, is difficult to represent with simple tests, the Taylor impact test is one of a number of tests devised for high strain rate complex loading. To expedite the acceptance of LPBF Ti6Al4V (ELI) for use in demanding structural applications, there is a need to develop numerical models based on the internal microstructural state variables to predict the performance of the alloy over a wide range of high strain rates using such complex tests. This paper documents the numerical simulation of Taylor impact tests for direct metal laser-sintered and post-processed Ti6Al4V (ELI—Extra Low Interstitial) alloy. A microstructural variable-based constitutive model was used to predict the mechanical properties (stresses and evolution of plastic strains) of the material. The corresponding material parameters of the model were based on the specific microstructure obtained upon post-process heat treatment. The model was first implemented as a user material subroutine in the explicit finite element program ABAQUS using the VUHARD subroutine. Subsequently, the symmetrical Taylor impact tests of Laser Powder Bed Fusion (LPBF) Ti6Al4V (ELI) parts were numerically simulated using the VUHARD subroutine at different impact velocities. The equivalent von Mises stress and plastic strain obtained from numerical simulations were compared with the analytical solutions based on the strain rates obtained. It was shown that the instantaneous and average absolute errors between the numerical and analytical values of the model were generally less than 5%. The mushroom end, commonly observed in a Taylor test specimen, was also seen in the numerical model.

Mantle deformation during opening of the Japan Sea back-arc: Insights from peridotite xenoliths, Kawashimo, southwest Japan

For a better understanding of plate dynamics such as the opening of Japan Sea back-arc basins, it is critical to know why and how back-arc spreading/rifting occurs adjacent to convergent plate boundaries. Two models have been proposed for the formation of Japan Sea back-arc basins: the “slab rollback model” and the “plume model”. We report here on 12 spinel peridotite xenoliths in the alkali basalt of the Cenozoic Kawashimo volcano in southwest Japan. These xenoliths are dominantly harzburgite with some lherzolite. The harzburgites and lherzolites show coarse-grained or porphyroclastic textures that record variable degrees of deformation. Olivine and spinel compositions indicate the samples are residual mantle peridotites formed under various degrees of partial melting. Olivine crystallographic preferred orientations in the xenoliths have orthorhombic patterns characterized by a strong [010] maximum, and this orthorhombic pattern implies that the olivine deformed by dislocation creep on the (010)[100] slip system. Using a sub-grain size piezometer, the maximum differential stress varies from 3 to 13 MPa in the samples. We also found that the peridotite xenoliths deformed under relatively high strain-rates, such as 10−13 to 10−10 s−1, using olivine flow laws and the obtained stress and grain size. The range of high strain-rates is comparable to that predicted using a thermomechanical model of back-arc spreading/rifting. Therefore, it is probable that the peridotite xenoliths preserve textures that formed during the mantle deformation that accompanied the Japan Sea back-arc spreading/rifting. We estimated an equilibrium temperature of 1238 ± 20 °C using the two-pyroxene geothermometer, and this temperature is higher than any temperature reported previously for peridotite xenoliths in southwest Japan. The obtained equilibrium P–T condition for the xenoliths implies that the hot mantle plume hypothesis best explains the mechanism of formation of Japan Sea back-arc basins.

High strain rates deformation behavior of an as-extruded Mg–2.5Zn–4Y magnesium alloy containing LPSO phase at high temperatures

Mg–Zn–Y magnesium alloys comprising long-period stacking ordered (LPSO) phase have shown excellent strengthening effects, however, their deformation behavior and microstructure evolution under different strain rates and temperatures have not yet been thoroughly investigated. This work is based on the investigation of elevated temperature and high strain rate deformation behavior of an as-extruded Mg–2.5Zn–4Y magnesium alloy comprising LPSO phase, with the strain rates lying in the 700 s−1 to 2100 s−1 range, and temperature ranging from 293 K to 623 K. Electron backscattering diffraction (EBSD), scanning electron microscopy (SEM), and optical microscopy (OM) was employed for investigating the deformation microstructure. The results show that at early deformation the extension twinning coordinates the plastic deformation first, subsequently, pyramidal < c+a > slip and kinking of LPSO phase can also coordinate deformation for the experimental alloy at high strain rates at high temperatures. A peculiar phenomenon of misaligned LPSO phase structures (1600 s−1, 623 K) was also discovered. The fracture mode of the experimental alloy is mainly the cleavage fracture or the mixed ductile-brittle fracture during high-speed impact. A modified Johnson–Cook (J-C) constitutive model of the as-extruded Mg–2.5Zn–4Y was found to appropriately analyze the stress–strain values by comparing the computed results with the experimentally obtained data. It was, thus, demonstrated that the modified J-C model can make a reasonable prediction about the dynamic mechanical behavior of a Mg–2.5Zn–4Y magnesium alloy in its as-extruded condition throughout a range of high temperatures and strain rates with a high degree of accuracy.

Experimental Study of the Dynamic and Static Compression Mechanical Properties of Closed-Cell PVC Foams.

Closed-cell polyvinyl chloride foam (PVC) possesses many advantages, including its light weight, moisture protection, high specific strength, high specific stiffness, and low thermal conductivity, and is widely used as the core material in composite sandwich structures. It is increasingly used in fields with light weight requirements, such as shipbuilding and aerospace. Some of these structures can be affected by the action of dynamic loads during their lifespan, such as accidental or hostile blast loads as well as wind-loaded debris shocks. Examining the material properties of PVC foams under dynamic load is essential to predict the performance of foam sandwich designs. In this study, the compressive responses of a group of PVC foams with different densities were investigated under a broad range of quasi-static conditions and high strain rates using a universal testing machine and a lengthened Split Hopkinson press bar (SHPB) fabricated from titanium alloy. The results show that the mechanical properties of foam materials are related to their density and are strain rate-sensitive. The compressive strength and plateau stress of the foams were augmented with increased foam density. In the quasi-static strain rate range, the compressive strength of PVC foams at 10−1 s−1 was 27% higher than that at 10−4 s−1. With a strain rate of 1700 s−1, the strength was 107% higher than the quasi-static value at 10−4 s−1.

Flow behavior and dynamic transformation of bimodal TC17 titanium alloy during high strain rate hot compression

The flow behavior and dynamic transformation of near β TC17 alloy with a bimodal structure were investigated by hot compression with the high strain rate range from 1 s −1 to 20 s −1 and in the temperature range from 840 °C to 900 °C in this study. The most evident discontinuous yielding and post strain hardening occur at 840 °C-20 s −1 due to its high α p volume fraction before compression and the subsequent strong work hardening effect. High strain rate can slightly promote dynamic transformation when alloy is compressed at 840 °C and 870 °C due to domination of the high flow stress and temperature raising. However, more dramatic dynamic transformation is obtained for 1 s −1 at 900 °C because the deformation heating at higher temperature/lower strain rate is less evident, and the deformation time thus maters more greatly on the phase transformation. The fine α s shows an obvious phase transformation priority than the coarse α p under all conditions due to the enhanced alloy element (Al) diffusivity resulting from enlarged α/β interface and higher dislocation (diffusion channel) density around it. The α p promotes the dynamic recrystallization of β phase while this effect becomes weaker when dynamic transformation is progressed greatly, mainly due to the inevitable stored energy consumption and reduced α p volume fraction caused by phase transformation. • Bimodal TC17 titanium alloy is hot compressed via high strain rate during α + β and β region. • Flow behavior and the morphology related phase transformation mechanism of α p and α s are analyzed. • Effect of dynamic transformation on DRX of β phase is discussed.

Double-humped temperature dependence of plastic behaviour of K403 superalloy and its constitutive model

ABSTRACT In this study, uniaxial compression experiments of K403 superalloy were conducted over temperature range of 298–1073 K and strain rate range of 0.1–5200/s. Temperature and strain rate effects on the flow stress were analysed. Double anomalous stress humps were noticed in the flow stress vs. temperature curves. The flow stress of the superalloy showed independence on strain rate over low strain rate range and an enormous increase with increasing strain rate over high strain rate range. Then, the effects of temperature and strain rate on the microstructure were observed and analysed. Due to the double-humped temperature dependence, the existing constitutive models were unable to accurately predict the plastic behaviour of K403 superalloy. Thus, a constitutive model was developed to describe the plastic behaviour of K403 superalloy. The model was able to capture the double-humped temperature dependence and anomalous strain rate dependence of plastic behaviour. It was shown that the plastic behaviour of the superalloy can be accurately predicted over a wide range of temperatures and strain rates.

Rheological behaviour of a La-based bulk metallic glass (BMG) used in 3D printing

ABSTRACT To be used as a new kind of three-dimensional printing material, rheological behaviour of a La-based bulk metallic glass (BMG) was studied over a wide range of high temperatures and strain rates by uniaxial compression experiments. The variations in peak stress and steady stress with temperature and strain rate were analysed. Three rheological regions were revealed for the BMG: a non-Newtonian, a Newtonian and an abnormal region which are determined by the temperature and strain rate. The variation on viscosity further indicates that the rheological mode transforms from Newtonian fluid to non-Newtonian fluid with the increase of strain rates at the same temperature. The results from scanning electron microscope test also confirm the microstructural changes that occurred at three different rheological modes. The crystallisation kinetics of La55Al25Ni5Cu10Co5 was studied by thermal analysis and the result show that the crystallisation process of La55Al25Ni5Cu10Co5 glassy alloy is the diffusion-controlled growth. The relationship among steady-state stress, strain rates and temperatures are determined by using hyperbolic function under high-temperature compression test. The curve shows that the logarithmic relationship between the steady-state stress and strain rates satisfies the linear relationship. Besides, the activation energy Q of this amorphous alloy in Newtonian rheological region is 131.31 kJ/mol.

A Study on Measuring Distribution of Temperature for Instrumented Taylor Impact Test

It is a challenge to apply the infrared detector to a test at higher strain rate because lots of articles report that the detector has an extremelyhigh responsiveness. However, all the research works about the measurement of temperature is focused on 103 s-1 of the strain rate achieved by the split Hopkinson pressure bar test. To evaluate the thermo-mechanical behaviour of materials in higher strain rate range, a method for measuring the temperature in Taylor impact test is required to establish. Additionally, a use of the fiber should be considered to protect the detector from any damages by the impact of the specimen and realize the measurement in the point-like area. In this study, an optically-measuring system of temperature with the infrared detector and PIR fiber is designed. Then, the designed system is introduced into the apparatus based on the instrumented Taylor impact test proposed recently. The temperature rise at a local point on the surface of pure aluminium is measured during the test. Then, a calculation for distribution of temperature from a heat conduction equation is proposed.

Constitutive model of GH4720Li high temperature nickel base alloy at high strain rate and large temperature range

The dynamic mechanical properties of GH4720Li nickel base superalloy under high and low strain rates in a wide temperature range have been studied, and a constitutive model with higher fitting progress have been established. The experimental results show that the abnormal phenomenon of dynamic mechanical properties of GH4720Li alloy appears under the condition of high strain rate. This is because the change of Cr (MO) content in precipitates and the change of precipitate morphology lead to the difference of dynamic mechanical properties of GH4720Li alloy at high and low strain rates. Besides, A new piecewise function model based on a phenomenological representation of the stress-strain curves is proposed to describe the constitutive equation of Nickel-based superalloy GH4720Li of stress-strain curves. Meanwhile, new methods to obtain the material constant k and C are proposed to predicted accurately the flow stress. The comparison between calculated values and experimental values based on the new constitutive modeling shows that these methods for obtaining material constants k and C are valid and the new function model is significant for establishing constitutive equations of Nickel-based superalloy GH4720Li in hot deformation processes.

A Combined Exponential-Power-Law Method for Interconversion between Viscoelastic Functions of Polymers and Polymer-Based Materials.

Understanding and modeling the viscoelastic behavior of polymers and polymer-based materials for a wide range of quasistatic and high strain rates is of great interest for applications in which they are subjected to mechanical loads over a long time of operation, such as the self-weight or other static loads. The creep compliance and relaxation functions used in the characterization of the mechanical response of linear viscoelastic solids are traditionally determined by conducting two separate experiments—creep tests and relaxation tests. This paper first reviews the steps involved in conducting the interconversion between creep compliance and relaxation modulus in the time domain, illustrating that the relaxation modulus can be obtained from the creep compliance. This enables the determination of the relaxation modulus from the results of creep tests, which can be easily performed in pneumatic equipment or simple compression devices and are less costly than direct relaxation tests. Some existing methods of interconversion between the creep compliance and the relaxation modulus for linear viscoelastic materials are also presented. Then, a new approximate interconversion scheme is introduced using a convenient Laplace transform and an approximated Gamma function to convert the measured creep compliance to the relaxation modulus. To demonstrate the accuracy of the fittings obtained with the method proposed, as well as its ease of implementation and general applicability, different experimental data from the literature are used.

Temperature, strain rate and anisotropy effects on compressive response of natural and synthetic cellular core materials

The remarkable flexural properties of sandwich structures hinge on the selection of performing core materials with suitable out of plane mechanical properties, i.e. compressive ones. For this reason, this work compares the compressive behaviour of a synthetic foam (polyvinyl chloride) and an environmentally friendly agglomerated cork as a function of density, strain rate, temperature and anisotropy. The strain rate sensitivity of these cellular materials was investigated in a wide range of velocity conditions by using drop weight tower and Split Hopkinson Pressure Bar dynamic compression tests. The results highlighted a remarkable strain rate sensitivity of both materials because of their viscoelastic nature and, in particular, an increase in compressive properties with increasing strain rate. This increment was more pronounced in the medium–high strain rate range than in the low-medium one. An embrittlement effect with decreasing temperature was detected, which compromises core materials crashworthiness determining a reduction of the percentage absorbed energy. Despite a remarkable anisotropy induced by the production processes, this work confirms the feasibility of agglomerated cork as a sustainable alternative to petroleum-based cellular core materials especially in consideration of the significant recovery capabilities that ensure a higher dimensional stability of the sandwich structure.

A comparative study on hot deformation behaviours of low-carbon and medium-carbon vanadium microalloyed steels

Carbon is an essential element in steel, but there are still discrepancies regarding its effect on steel hot deformation behaviours. In this research, isothermal compression tests were carried out for a low-carbon (0.05 C) and a medium-carbon (0.38 C) vanadium microalloyed steel with deformation temperatures of 900−1050 °C and strain rates of 0.01−30 s−1. It was found that carbon causes a softening effect at low strain rates (0.01−1.0 s−1), while a hardening effect at high strain rates (10.0−30 s−1). Through constitutive analysis, the hot deformation activation energy for 0.05 C steel is 305.9 kJ/mol in the whole strain rate range, while for 0.38 C steel, the activation energy is 292.3 kJ/mol in the low strain rate range (0.01−1 s−1) and 475.0 kJ/mol in the high strain rate range (10−30 s−1). It was proposed that the addition of carbon decreases the deformation activation energy at low strain rates (0.01−1 s−1), due to its positive influence on the self-diffusion coefficient of iron, which increases the rates of dislocation climb and recovery. On the other hand, carbon lowers the stacking fault energy of austenite, which could make partial dislocation collapse more difficult than dislocation climb and thus becomes the rate-controlling mechanism for 0.38 C steel at high strain rates (10−30 s−1). This gives rise to the higher activation energy and work hardening rate of 0.38C steel at high strain rates. Comparing the power-dissipation-efficiency maps, two peak domains were found in those of 0.38 C steel, while only one peak domain exists in those of 0.05 C steel.

Effect of Strain Rate on Compressive Behavior of a Zr-Based Metallic Glass under a Wide Range of Strain Rates.

The strain rate effect on the mechanical behavior of amorphous alloys has aroused general interest. Most studies in this area have focused on quasi-static and high strain-rate compressive deformations. However, experimental results have been few, or even non-existent, under a moderate strain-rate loading. This article extends the traditional split Hopkinson pressure bar (SHPB) technique to characterize compressive deformation of an amorphous alloy at medium strain rates. The compressive behavior of Zr65.25Cu21.75Al8Ni4Nb1 amorphous alloy shows a negative strain rate effect on the yield strength with a quasi-static, moderate to high strain-rate range, and the fracture angle increases from 44° at 10−5 s−1 to 60° at 4000 s−1 as strain rate increases. Herein, we introduce a modified cooperative shear model to describe the compressive behavior of the current amorphous alloy under a broad strain rate range. The model predicts that the normalized yield strength will linearly descend with logarithmic strain rate when the strain rate is less than a critical strain rate, however, which rapidly decreases linearly with the square of the strain rate at high strain rates. The predicted data of the model are highly consistent with the current experimental results. These findings provide support for future engineering applications of amorphous alloys.

A study on the dynamic mechanical behavior and microtexture of 6082 aluminum alloy under different direction

The dynamic mechanical behavior and texture of 6082 aluminum alloy along the rolling direction (RD), transverse to the rolling direction (ND), and perpendicular to the rolling direction (TD) were examined within a high strain rate range of 1000 s−1-6000 s−1, using the split Hopkinson pressure bar and X-ray diffraction (XRD). The results indicated that the yield strength and peak flow stress on the RD plane of the material increased as a function of the flow stress, while the flow stresses on the ND and TD planes showed obvious regionalization, with 3900 s−1 being the critical strain rate for regionalization. Analysis of the orientation distribution functions (ODFs) revealed that before dynamic impact, the main textures on the RD, ND, and TD planes were brass {011} <2 1 1>, copper {012} <1 1 1>, and S<123>{634} textures, respectively.