微量稀土钇对Cu-Cr-Zr合金时效性能的影响

研究了微量稀土钇对Cu-Cr-Zr合金时效后导电率和显微硬度的影响。结果表明:Cu-0.41Cr-0.10Zr合金在950℃固溶1 h后,在480℃时效2h能获得较高的显微硬度和导电率;时效前冷变形可加快第二相的析出,使其性能得到显著提高。固溶后经60%变形后于480℃时效1 h其显微硬度和导电率分别高达154.3HV和81.5%IACS,而固溶后直接时效时仅为110.2HV和65.2%IACS。微量稀土元素Y的加入,使Cu-0.39Cr-0.11Zr-0.041Y合金的显微硬度较Cu-0.41Cr-0.10Zr合金高9HV,而导电率略有降低。     

Microstructure and mechanical behavior of spray-deposited High-Li Al-Li alloys

High-Li alloys, with the composition Al-3.8Li-XCu-1.0Mg-0.4Ge-0.2Zr, were synthesized using a spray deposition technique (wt. pct, X=0∼1.5). The microstructure of the spray-deposited Al-Li alloys consisted of equiaxed grains with an average grain size in the range from 20 to 50 μm. The grain-boundary phases were fine and discrete. The spray-deposited and thermomechanically processed materials were isothermally heat treated at 150 °C and 170 °C to investigate the age-hardening kinetics. It was noted that the spray-deposited Al-3.8Li-XCu-1.0Mg-0.4Ge-0.2Zr alloys exhibited relatively sluggish aging behavior. The peak-aged condition was achieved at 170 °C in the range from 20 to 90 hours. It was noted that Cu increases the hardness of alloys during aging. Moreover, the influence of Cu on age-hardening kinetics is marginal. The mechanical properties of the spray-deposited and extruded Al-Li alloys were studied in the underaged, peak-aged, and overaged conditions. For example, the peak-aged yield strength, tensile strength, and ductility of Al-3.8Li-1.0Cu-1.0Mg-0.4Ge-0.2Zr are 455 MPa, 601 MPa, and 3.1 pct, respectively. Moreover, an increase in the Cu content of the alloy led to improvements in strength, with only slight changes in ductility, for Cu contents up to 1.0 wt pct. Beyond this range, an increase in Cu content led to decreases in both strength and ductility.     

Tensile strength of thermomechanically processed Cu-9Ni-6Sn alloys

The tensile properties of Cu-9Ni-6Sn alloys with different swaging amounts of 64, 77, and 95 pct, either solutionized and aged (S/A) or directly aged (D/A), were examined as a function of aging time. It was found that the aging response of Cu-9Ni-6Sn alloys varied greatly depending on the prior solution heat treatment before aging and/or different swaging amounts. The swaged S/A Cu-9Ni-6Sn alloys showed a multistage increase in tensile strength with respect to aging time, probably due to the sequential occurrence of spinodal decomposition, formation of metastable γ· precipitates, and recrystallization. The effect of different swaging amounts, ranging from 64 to 95 pct, was minimal on the aging response of S/A specimens. The prior cold working, however, appeared to favor the spinodal strengthening, comparing unswaged and swaged S/A Cu-9Ni-6Sn alloys. In 95 pct swaged D/A Cu-9Ni-6Sn alloys, the level of hardening was much less sensitive to aging time. A complex interaction between the reduction in dislocation density, the formation of equilibrium precipitates, and the reduction of Sn content in the Sn-rich segregates during an aging process is believed to be responsible for such a lean sensitivity. The increases in tensile strength of 64 and 77 pct swaged D/A Cu-9Ni-6Sn alloys were found to be much steeper than that in the 95 pct counterparts in the early and intermediate stages of aging, which is believed to be related to the relative contribution from work hardening and precipitation hardening to the strength level of D/A specimens.     

固溶时效对上引拉铸Cu-0.3Cr-0.1Zr组织性能的影响

用扫描电镜(SEM)、透射电子显微镜(TEM)、涡流电导率测量仪和万能试验机测试分别测量了上引拉铸拉拔之后固溶时效对Cu-0.3Cr-0.1Zr合金抗拉强度及导电率性能的影响,用金相显微镜观察不同拉拔加工率下固溶的显微组织.并探讨了合金的强化机理.结果表明:上引Cu-0.3Cr-0.1Zr合金铸锭经过75％冷拉变形后固溶其组织和力学性能较好.经时效后的固溶态Cu-0.3Cr-0.1Zr合金,抗拉强度和导电率迅速上升,随着时间时间的延长,其抗拉强度达到峰值后呈下降趋势,而导电率则继续上升.Cu-Cr-Zr合金析出强化的重要因素是大量共格弥散的析出相,以共格强化机制估算的强化值423MPa与实验结果415MPa相近.     

Structure and properties of a rapidly solidified Al-Li-Mn-Zr alloy for high-temperature applications: Part II. spray atomization and deposition processing

A new Al-Li alloy containing 2.3 wt pct Li, 6.5 wt pct Mn, and 0.65 wt pet Zr for high-temperature applications has been processed by a rapid solidification (RS) technique (as compacts by spray atomization and deposition) and then thermomechanically treated by hot extrusion. As-received and thermomechanically treated deposits were characterized by X-ray diffraction and scanning electron microscopy (SEM). Phase analyses in the as-processed materials revealed the presence of two Mn phases (Al₄Mn and Al₆Mn), one Zr phase (Al₃Zr), two Li phases (the stable AlLi and the metastable Al₃Li), and the aAl solid solution with high excess in Mn solubility (up to close the nominal composition in the as-atomized powders). As-deposited and extruded pieces were given heating treatments at 430 °C and 530 °C. A two-step aging treatment was practiced, to check for the optimal (for tensile properties) aging procedure, which was found to be the following: solutioning at 430 °C for 1 hour and water quenching + a first-step aging at 120 °C for 12 hours + a second-step aging at 175 °C for 15 hours. The mechanical properties, at room and elevated temperatures, of the hot extruded deposits are compared, following the optimal solutioning and aging treatments. The room-temperature (RT) strength of the proposed alloy is distinctly better for the as-deposited specimens (highest yield strength, 320 MPa) than for the as-atomized (highest yield strength, 215 MPa), though less than 65 pct of the RT strength is conserved at 250 °C. Ultimate strengths are quite comparable (in the 420 to 470 MPa range). Ductilities at RTs are in the low 1.5 to 2.5 pct range and show no improvement over other Al-Li alloys.     

High-strength Cu-Ni-Sn alloys by thermomechanical processing

The influence of prior cold work on the aging characteristics and mechanical properties response for copper-rich alloys in the Cu-Ni-Sn system has been investigated. It has been established^15,16 that there exists a spinodal mode of decomposition below a critical temperatureT _R, 200 to 300°C below the equilibrium phase boundary in this system. Significant age hardening response is observed in this region; however, fracture ductility is severely impaired due to a grain boundary precipitate network which develops after relatively short aging times. Cold work prior to low temperature aging is found to have relatively little influence on the incubation time for this embrittling network. It does, however, profoundly enhance the kinetics of the continuous (spinodal) transformation. It is observed that for broad variations in composition, critical combinations of prior cold work, aging time and temperature yield material with unique combinations of. yield stress and fracture ductility (for example, a Cu-9 wt pct Ni-6 wt pct Sn alloy may be processed to exhibit an 0.01 pct offset yield of 174,000 psi in conjunction with a 55 pct R.A. on fracture; significantly higher 0.01 pct offset yield values may be achieved at some reduction in fracture ductility for other NiJSn ratios). It is concluded that the resultant ductileJbrittle properties response is a consequence of a critical compctitive balance between amplitude development in the modulated structure and nucleation of the grain boundary network. The minimum level of prior cold work required to effect this balance in the Cu-9 wt pct Ni-6 wt pct Sn alloy is 75 pct R.A. The present levels of yield stressJfracture ductility values reported, to the best of our knowledge, are unsurpassed by those of any other copper-base alloy system (at a significant cost reduction to the Cu-Be alloys) and suggest the potential yet to be realized in other systems exhibiting this mode of decomposition.     

Correlation between the cold-working and aging treatments in a Cu-15 Wt Pct Cr in situ composite

The cold-working and aging treatments are the two most important materials processing techniques used to produce the high strength and high conductive Cu in situ composites. In this work, we systematically investigated the relationship between these two techniques in a Cu-15 wt pct Cr in situ composite by means of the electrical conductivity measurement, hardness testing, tensile testing, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). In contrast to the solution-treated samples, the cold working significantly improves the electrical conductivity but only produces a moderate hardening effect during the subsequent aging treatment. This is attributed to the rapid precipitation of incoherent Cr phases due to the high vacancy density in the Cu matrix after the cold deformation. At high aging temperature, the hardness and tensile strength of the material decreases significantly due to a pronounced process of recovery and recrystallization in the Cu matrix, as well as the recovery in the Cr fibers. When aged for 1 hour, an optimum aging temperature of 715 K is recommended.     

High-strength Cu-Ni-Sn alloys by thermomechanical processing

The influence of prior cold work on the aging characteristics and mechanical properties response for copper-rich alloys in the Cu-Ni-Sn system has been investigated. It has been established^15,16 that there exists a spinodal mode of decomposition below a critical temperatureT _R, 200 to 300°C below the equilibrium phase boundary in this system. Significant age hardening response is observed in this region; however, fracture ductility is severely impaired due to a grain boundary precipitate network which develops after relatively short aging times. Cold work prior to low temperature aging is found to have relatively little influence on the incubation time for this embrittling network. It does, however, profoundly enhance the kinetics of the continuous (spinodal) transformation. It is observed that for broad variations in composition, critical combinations of prior cold work, aging time and temperature yield material with unique combinations of. yield stress and fracture ductility (for example, a Cu-9 wt pct Ni-6 wt pct Sn alloy may be processed to exhibit an 0.01 pct offset yield of 174,000 psi in conjunction with a 55 pct R.A. on fracture; significantly higher 0.01 pct offset yield values may be achieved at some reduction in fracture ductility for other NiJSn ratios). It is concluded that the resultant ductileJbrittle properties response is a consequence of a critical compctitive balance between amplitude development in the modulated structure and nucleation of the grain boundary network. The minimum level of prior cold work required to effect this balance in the Cu-9 wt pct Ni-6 wt pct Sn alloy is 75 pct R.A. The present levels of yield stressJfracture ductility values reported, to the best of our knowledge, are unsurpassed by those of any other copper-base alloy system (at a significant cost reduction to the Cu-Be alloys) and suggest the potential yet to be realized in other systems exhibiting this mode of decomposition.     

Effect of titanium,niobium and zirconium on creep rupture strength and ductility of cobalt base superalloys

An attempt has been made to develop a cobalt base casting superalloy (30Cr-10Ni-7W-Co) having high creep rupture strength and ductility for first stage nozzles of gas turbines. In cobalt base superalloys, there was found to exist a close correlation between the creep rupture strength and MC type carbide forming elements such as Ti, Nb and Zr. In cobalt base alloys with 0.25 wt pct C, precipitation and coarsening of carbides can be reduced by addition of Ti, Nb and Zr. Therefore, by adding the optimum amount of Ti, Nb and Zr, precipitation of carbides in the alloy reaches such an amount as to give the highest creep rupture strength. Excess addition of Ti, Nb and Zr does not improve the creep rupture strength. By adding C, creep rupture strength of the cobalt alloy with Ti, Nb and Zr can be improved and becomes the highest at 0.40 wt pct. C. According to the experimental results, the creep rupture strength becomes the highest at a value of (Ti + Nb + Zr)/C (atomic ratio) of about 0.3. Contrary to the expectation, it was found in this experiment that the ductility in creep rupture tests increases with increasing carbon content up to 0.6 wt pct.     

固溶时效处理对Al-6.6Zn-2.3Mg-2.1Cu-0.12Zr合金组织性能的影响

采用光学显微镜、扫描电镜、透射电镜、X射线衍射、硬度测试、电导率测试和室温拉伸性能测试等分析手段,研究了Al-6.6Zn-2.3Mg-2.1Cu-0.12Zr合金挤压板带固溶、单级时效和双级时效制度下的组织和性能。研究表明,Al-6.6Zn-2.3Mg-2.1Cu-0.12Zr合金挤压板带采用475℃/2 h的固溶处理制度,析出相回溶充分,无过烧现象;合金采用475℃/2 h+120℃/24 h的T6时效处理制度,晶内析出相细小弥散,晶界析出相连续分布;合金采用475℃/2 h+110℃/8 h+160℃/28 h的T74双级固溶时效处理制度,晶内析出相以η’和η为主,晶界析出物完全断开。     

Microstructure and properties of as-cast Cu-Cr-Zr alloys with lanthanum addition

Cu-0.45Cr-0.2Zr-xLa (x = 0–0.48) alloys were prepared by vacuum casting. The effects of La addition and orientation on the microstructure and properties of the as-cast alloy were investigated by an optical microscope, a scanning electron microscope with an energy dispersive X-ray spectrometer, a tensile testing machine and an electrical conductivity tester. The result shows that the addition of La significantly refines the columnar grainsize and decreases the secondary dendrite arm spacing. Trace addition of La improves the room temperature ultimate tensile strength, elongation and electrical conductivity mainly by purifying during melting and casting. The ultimate tensile strength, elongation and electrical conductivity significantly decrease with the increase of La content due to formation of coarse particles and oxides, which severely harm the performance of the Cu-0.45Cr-0.2Zr-xLa alloys. The Cu-0.45Cr-0.2Zr-0.13La alloy possesses a good combination of room temperature ultimate tensile strength, elongation and electrical conductivity. In addition, room temperature ultimate tensile strength and electrical conductivity along transverse direction of the ingot are higher than that along longitudinal direction, which is mainly ascribed to different distribution of grain boundary and grain orientation.     

Structure and properties of a rapidly solidified Al-Li-Mn-Zr Alloy for high-temperature applications: Part I. inert gas atomization processing

A new Al-Li alloy containing 2.3 wt pct Li, 6.5 wt pct Mn, and 0.65 wt pet Zr, for high-temperature applications, has been processed by a rapid solidification (RS) technique (as powders by inert gas atomization) and then thermomechanically treated by hot isostatic pressing (hipping) and hot extrusion. As-received and thermomechanically treated powders (of various size fractions) were characterized by X-ray diffraction and scanning and transmission electron microscopy (SEM and TEM, respectively). Phase analyses in the as-processed materials revealed the presence of two Mn phases (Al₄Mn and Al₆Mn), one Zr phase (Al₃Zr), two Li phases (the stable AlLi and the metastable Al₃Li), and the αAl solid solution with high excess in Mn solubility (up to close the nominal composition in the as-atomized powders). Extruded pieces were solutionized at 370 °C and 530 °C for various soaking times (2 to 24 hours). A variety of aging treatments was practiced to check for the optimal (for tensile properties) aging procedure, which was found to be the following: solutioning at 370 °C for 2 hours and water quenching + 1 pct mechanical stretching + one step aging at 120 °C for 3 hours. The mechanical properties, at room and elevated temperatures, of the “hipped” and hot extruded powders are compared following the optimal solutioning and aging treatments. The results indicate that Mn is indeed a favorable alloying element for rapidly solidified Al-Li alloys to retain about 85 to 95 pct of the room-temperature tensile properties even at 250 °C, though room-temperature strength is not satisfactory in itself. However, specific moduli are by 20 to 25 pet higher than those of the 2024 series duralumin-type alloys. Ductilities at room temperatures are in the low 1 to 2.5 pct range and show no improvement over other Al-Li alloys.     

Microstructure-property relationships of two AI-3Li-2Cu-0.2Zr-XCd alloys

The microstructure and tensile properties of two A1-3 wt pct Li-2 wt pct Cu-0.2 wt pct Zr alloys, one Cd-free and one containing 0.2 wt pct Cd, have been investigated. The Cd-free alloy remained unrecrystallized for all solutionizing treatments studied, whereas a special treatment had to be developed to prevent recrystallization during solutionizing of the 0.2 wt pct Cd alloy. In combination with cadmium, zirconium either enters into, or nucleates on, the course Al₇Cu₂Fe and T₂ phases during high temperature annealing. This reduces the volume fraction of small coherent Al₃Zr particles in the matrix which normally inhibits recrystallization. Consequently, a low temperature anneal to precipitate Al₃Zr is necessary prior to high temperature solutionizing in order to prevent recrystallization in the Cd-containing alloy. Unlike its effect in lower lithium, higher copper content aluminum alloys, cadmium does not significantly affect the nucleation of the strengthening precipitates. If anything, cadmium has a detrimental effect on the age hardening response of this alloy, since it increases the formation of coarse Al-Cu-Li equilibrium phases at grain and subgrain boundaries and thus removes some of the copper and lithium from participating in the formation of the strengthening precipitates T₁ and δ′. Subgrain boundary fracture occurred during tensile tests of both alloys in the unrecrystallized condition; however, transgranular fracture occurred in tests of the partially recrystallized 0.2 wt pct Cd alloy. Both types of fractures are believed due to a form of strain localization associated with precipitate free zones and shearable precipitates. Formerly with the Fracture and Fatigue Research Laboratory, Georgia Institute of Technology, Atlanta, GA     

Strength and electrical conductivity of a deformation-processed Cu-5 Pct Nb composite

A Cu-5 pct Nb alloy was deformation processed by wire drawing to very large reductions (99.9993 pct) and the strength and electrical conductivity properties compared with similarly deformation processed Cu-20 pct Nb. The results showed that the Cu-5 pct Nb alloy was transformed into a composite material with the original Nb dendrites becoming ribbonlike filaments in a similar fashion to higher Nb-containing Cu-Nb alloys. The degree of strength increase with increasing deformation processing greatly exceeds rule-of-mixtures expectations at higher degrees of deformation processing, where the Nb becomes highly aligned with the wire axis. A 5 pct Nb addition appears to contain close to the minimum amount of Nb phase necessary to produce appreciable strengthening during deformation processing of Cu-Nb alloys. The strength-conductivity properties of the deformation-processed Cu-5 pct Nb alloy show significant improvements in strength over the best commercial alloys in the conductivity range of 80 to 90 pct international annealed copper standard (IACS). This article is based on a presentation made in the symposium “High Performance Copper-Base Materials” as part of the 1991 TMS Annual Meeting, February 17–21, 1991, New Orleans, LA, under the auspices of the TMS Structural Materials Committee.     

The effect of processing and microstructure development on the slip and fracture behavior of the 2.1 wt pct Li AF/C-489 and 1.8 wt pct Li AF/C-458 Al-Li-Cu-X alloys

Although Al-Li-Cu alloys showed initial promise as lightweight structural materials, implementation into primary aerospace applications has been hindered due in part to their characteristic anisotropic mechanical and fracture behaviors. The Air Force recently developed two isotropic Al-Li-Cu-X alloys with 2.1 wt pct Li and 1.8 wt pct Li designated AF/C-489 and AF/C-458, respectively. The elongation at peak strength was less than the required 5 pct for the 2.1 wt pct Li variant but greater than 10 pct for the 1.8 wt pct Li alloy. The objectives of our investigations were to first identify the mechanisms for the large difference in ductility between the AF/C-489 and AF/C-458 alloys and then to develop an aging schedule to optimize the microstructure for high ductility and strength levels. Duplex and triple aging practices were designed to minimize grain boundary precipitation while encouraging matrix precipitation of the T₁ (Al₂CuLi) strengthening phase. Certain duplex aged conditions for the AF/C-489 alloy showed significant increases in ductility by as much as 85 pct with a small decrease of only 6.5 and 2.5 pct in yield and ultimate tensile strength, respectively. However, no significant variations were found through either duplex or triple aging practices for the AF/C-458 alloys, thus, indicating a very large processing window. Grain size and δ′ (Al₃Li) volume fraction were determined to be the major cause for the differences in the mechanical properties of the two alloys.     

Synthesis and Characterization of Novel Chromium-Free Nickel Alloy Electrode Materials

The synthesis of two Cr-free nickel-based alloys designated as 1S with 6.5 pct Mn and 2H without Mn of compositions varying between 40 to 43.5Ni, 20Mo, 22 to 25Fe, 10Cu, 6.5 to 0Mn, 1Ti, and 0.5Al (wt pct) as filler materials for TIG welding application was performed. New filler materials were developed to reduce carcinogenic hexavalent chromium (Cr⁶⁺) fumes generated during the welding of 300 series austenitic stainless steel. The Cr-free nickel alloys were characterized for microstructure and mechanical properties. The developed alloys showed good microstructure stability in as-cast and solution-treated conditions. A material properties simulation software JMatPro predicted that 2H alloy has 2 wt pct more γ (solid solution) phase than in 1S but has 2.2 wt pct less γ′ (strengthening precipitates) phase than in 1S alloy. The tensile strength of 1S alloy was about 2.2 pct more than 2H. The solution treatment of both alloys decreased the hardness, tensile and yield strengths by about 21 pct but ductility improved by about 17 pct. Fracture studies of both alloys showed the ductile mode of failure.     

Computer-Aided Design of Manufacturing Chain Based on Closed Die Forging for Hardly Deformable Cu-Based Alloys

Two copper-based alloys were considered, Cu-1 pct Cr and Cu-0.7 pct Cr-1 pct Si-2 pct Ni. The thermal, electrical, and mechanical properties of these alloys are given in the paper and compared to pure copper and steel. The role of aging and precipitation kinetics in hardening of the alloys is discussed based upon the developed model. Results of plastometric tests performed at various temperatures and various strain rates are presented. The effect of the initial microstructure on the flow stress was investigated. Rheologic models for the alloys were developed. A finite element (FE) model based on the Norton–Hoff visco-plastic flow rule was applied to the simulation of forging of the alloys. Analysis of the die wear for various processes of hot and cold forging is presented as well. A microstructure evolution model was implemented into the FE code, and the microstructure and mechanical properties of final products were predicted. Various variants of the manufacturing cycles were considered. These include different preheating schedules, hot forging, cold forging, and aging. All variants were simulated using the FE method and loads, die filling, tool wear, and mechanical properties of products were predicted. Three variants giving the best combination of forging parameters were selected and industrial trials were performed. The best manufacturing technology for the copper-based alloys is proposed.     

Microstructural size effects in high-strength high-conductivity Cu-Cr-Nb alloys

Microstructural refinement to further improve the strength and stability of high-strength high-conductivity Cu-Cr-Nb alloys was attained by mechanical milling (MM). Mechanically milled Cu-4Cr-2Nb and Cu-8Cr-2Nb exhibited an increase in hot-pressed Vickers hardness of 122 and 96 pct, respectively. Mechanical milling produced a corresponding decrease in electrical conductivity of ∼33 pct for both alloys. The increase in hardness was more due to Cu grain-size refinement than to second-phase particle-size refinement. The drop in conductivity was due to second-phase particle-size refinement, which both increased particle/matrix interfacial area and solute solubility. Mechanically processed Cu-4Cr-2Nb displayed an enhanced thermal stability. Hot-pressed 4-hour milled Cu-4Cr-2Nb experienced a 30 pct increase in conductivity with only a 22 pct drop in hardness when annealed at 1273 K for 50 hours. Such changes were largely due to an increase in dispersed-particle size (i.e., a decrease in solute and interfacial electron scattering) and Cu grain size (reduced Hall-Petch effect), respectively. The optimum hardness and conductivity combination was found in 4-hour milled and hot-pressed Cu-4Cr-2Nb material.     

预应变与预时效对6101导电铝合金组织与性能的影响

在人工时效基础上引入预应变与预时效以提高6101铝合金的力学与导电性能。通过性能检测与组织观察,研究了合金在人工时效热处理（固溶+时效）及引入预应变与预时效后的热处理（固溶+预应变+时效,固溶+预时效+预应变+再时效）过程中显微组织、力学性能及导电性能的变化规律。结果表明:当合金经过60%冷轧变形再在180℃时效6 h后,其抗拉强度与电导率分别达到262 MPa及55.7% IACS,高于一般人工时效后的合金。当合金在180℃预时效2 h后经过60%冷轧变形,再在180℃时效6 h后,其抗拉强度与电导率进一步提升至289 MPa与58.0% IACS。引入预应变与预时效后所产生的应变强化与析出强化的交互作用,是合金的力学性能和导电性能得到提升的根本原因。      

The Microstructure and tensile properties of a splat-quenched Al-Cu-Li-Mg-Zr alloy

The microstructure and tensile behavior of an Al-3Cu-l.6Li-0.8Mg-0.2Zr alloy, produced by splatquenched powder metallurgy processing, were studied. The alloy exhibited homogeneous deformation, both in bulk samples and duringin situ TEM studies. This is in contrast to the strain localization that is frequently observed in Mg-free Al-Cu-Li-X alloys. The difference in deformation mode is attributed to a fine distribution of Ś (Al₂CuMg) which precipitates up to the grain boundaries. A processing treatment involving 2 pct stretch prior to aging resulted in a yield strength of 555 MPa, a reduction in area of 29 pct, and a strain to fracture of 8.8 pct. This represents an attractive improvement in specific properties compared with 7075-T76 having a similar texture.