共查询到20条相似文献,搜索用时 31 毫秒
1.
2.
Younghwan Jang Sangshik Kim Seungzeon Han Chayong Lim Masahiro Goto 《Metals and Materials International》2008,14(2):171-175
The tensile properties of two- and three-layered accumulative roll-bonding (ARB) processed copper sheets containing deoxidized
low-phosphorous copper (DLP) and PMC90 are investigated with varying numbers of ARB process cycles. The tensile strength of
the DLP is determined by the applied equivalent strain, showing that the tensile strength values for both 2-L and 3-L ARBed
DLP specimens follow a single trend line. Unlike the DLP, the 3-L ARBed PMC90 follows a trend line that is completely different
compared to that of its 2-L counterpart above an equivalent strain value of 7.6, suggesting that the amount of applied equivalent
strain alone does not control the tensile strength of PMC90. The mechanism determining the tensile behavior of 2-L and 3-L
ARB processed commercially pure copper sheets is discussed. 相似文献
3.
4.
S. H. Huang 《Journal of Materials Engineering and Performance》2018,27(7):3199-3205
Effects of 1.5 wt.% Ag addition and solid solution?+?artificial ageing at 160 °C on the microstructure and mechanical properties of a Mg-5Sn alloy have been studied. The results show that Ag addition has significantly hardened the solution-treated Mg-5Sn alloy. During the ageing process, the hardness increase rate and the strength and ductility of the Mg-5Sn alloy at each state are also improved by Ag addition. The improved strengthening behavior is primarily attributed to the refinement distribution of the Mg2Sn precipitates, the enhanced precipitation process, and the synergistic strengthening effect of Mg2Sn and a metastable plate DO19 phase formed at lower ageing temperature. For each solution-treated alloy, the strength and ductility are higher than the corresponding cast ones. Ageing further enhances the yield strength, and the ductility of the Mg-5Sn-1.5Ag alloy is also increased after ageing. The fracture surfaces of the both peak-aged alloys exhibit the characteristic of a mixture of quasi-cleavage and ductile fracture. 相似文献
5.
以Cu-2.5Fe-0.03P高强高导铜合金带材为研究对象,测试不同处理状态合金板材的力学性能和电学性能,采用金相和电子显微分析方法研究该合金不同加工热处理状态下的组织与性能演变规律及其时效析出特性.并在此基础上研究微量元素Fe和P在合金中的存在形式和作用机制.结果表明:Cu-2.5Fe-0.03P合金热轧后在线固溶态合金基本上为单相固溶体,合金硬度、强度和电导率较低,塑性较好,但还存在少数未溶的Fe相外,在线固溶效果有待进一步改善;软化退火后的薄带进一步冷轧并时效后,合金成品薄带的显微硬度、抗拉强度、屈服强度、伸长率和电导率分别达到147 HV、456 MPa、271 MPa、10.7%和29.9 S/m;热轧-在线固溶-冷轧-时效态Cu-2.5Fe-0.03P合金中的Fe和P以Fe_3P和Fe相形式存在,合金的高强度来源于形变热处理产生的亚结构强化及Fe_3P和Fe粒子的析出强化. 相似文献
6.
The microstructure and mechanical properties of a 2024 Al alloy subjected to different levels of cold-rolling at room temperature and their evolution upon ageing at 453 K were investigated by means of microhardness measurements, tensile tests and transmission electron microscopy. The cold-worked 2024 Al alloy showed double-peak age strengthening behavior. After ageing for 120 min, the samples reached the first peak strength with quite low ductility. However, simultaneous high strength and ductility were achieved by prolonged ageing of 720 min. The first strengthening peak is due to the precipitation of fine S′ precipitates. The optimized mechanical properties of high strength and suitable ductility are attributed mainly to the precipitation of Ω-phase particles at the expense of S′ precipitates after ageing for 720 min. The Ω precipitates are effective in dislocation pinning and accumulation, and they can undergo plastic deformation to some extent, leading to simultaneously improved tensile strength, work-hardening ability and ductility. The present finding sheds light on the development of processing techniques to optimize the mechanical properties of 2024 Al alloy. 相似文献
7.
Tensile properties,microstructural evolution and fracture toughness of A1 2014 alloy subjected to cryorolling followed by warm rolling(CR + WR)have been investigated in the present study.The solution-treated(ST)A1 2014 alloy is cryorolled followed by warm rolling process at different temperatures(110,170 and 210 ℃).The mechanical properties and microstructural features of deformed and undeformed A1 2014 alloys were characterised by optical microscopy,transmission electron microscopy(TEM)and scanning electron microscopy(SEM).The CR + WR samples at 170 ℃ showed an improved hardness(179 HV),tensile(UTS 499 MPa,YS 457 MPa)and fracture toughness(K_Q= 37.49 MPa m~(1/2),K_(ee) = 37.39 MPa m~(1/2) and J integral= 33.25 kJ/mm~2)with respect to ST alloy as measured from the tensile and fracture toughness test.The improved mechanical properties of CR + WR alloy are attributed to grain boundary strengthening,combined recovery and recrystallisation,precipitation hardening and dynamic ageing effect during the deformation.The precipitation of metastable spherical phase Al_2Cu was responsible for the improved tensile and fracture properties of finegrained A1 2014 alloy observed in the present work. 相似文献
8.
Guohua Wu Chunchang Shi Liang Zhang Wencai Liu Antao Chen Wenjiang Ding 《金属学报(英文版)》2020,33(9):1243-1251
The effect of different ageing processes on microstructure and mechanical properties of cast Al–3 Li–2 Cu–0.2 Zr alloy was investigated using transmission electron microscopy and tensile tests. The results showed that the mean size of δ′-Al_3 Li particles and the number density of Cu-rich precipitates both increased with increasing ageing temperature from 150 to 190 °C for 24 h, resulting in increasingly high strength. In contrast, the ductility deteriorated with the increase in ageing temperature as a result of the intensified planar slip. The duplex low-to-high ageing treatment(120 °C for 6 h followed by 160 °C for 24 h) was shown to be beneficial to the ductility compared with the corresponding single-stage ageing treatment(160 °C for 24 h). The reduced slip length induced by the precipitation of θ′-Al 2 Cu phases was found to be mainly responsible for this ductility improvement. 相似文献
9.
《中国有色金属学会会刊》2020,30(4):905-916
An improved method of friction stir processing (FSP) was introduced for the processing of AZ91 magnesium alloy specimens. This novel process was called “friction stir vibration processing (FSVP)”. FSP and FSVP were utilized to develop surface composites on the studied alloy while SiC nanoparticles were applied as second-phase particles. The effect of reinforcing SiC particles with different sizes (30 and 300 nm) on different characteristics of the composite surface was studied. The results indicated that the microstructure was refined and mechanical properties such as hardness, ductility, and strength were enhanced as FSVP was applied. Furthermore, it was concluded that the effect of reinforcing particles with a size of 30 nm on the microstructure and mechanical properties of the surface composite was more obvious than that of particles with a size of 300 nm. It was also found that mechanical properties and microstructure of FSV-processed specimens were improved as vibration frequency increased. The hardness value in the stir zone was about 157 MPa for the FSV-processed specimen at a vibration frequency of 50 Hz, while this value was around 116 MPa for the FSV-processed specimen at a vibration frequency of 25 Hz. 相似文献
10.
Effect of heat treatment on eutectic silicon morphology and mechanical property of Al-Si-Cu-Mg cast alloys 总被引:2,自引:0,他引:2
1 INTRODUCTIONCastAl Sibasealloysareoneofthemostimpor tantaluminumalloysattributedtotheirlowdensity ,highspecificstrength ,excellentcasting properties ,mechanicalpropertiesanderosionresistance .TheseAl Sialloysaremainlyappliedinautomotive ,aerospace ,transportationandmechanicalindustry ,etc[1,2 ] .The propertiesofalloyscanbeimprovedthroughaddingCuandMgelementsintothealloys .Inthe processofsolutiontreatment ,alloyingele mentscompletelydissolveandformsupersaturatedsolidsolution .However… 相似文献
11.
Min Xiaohua Xiang Li Li Mingjia Yao Kai Emura Satoshi Cheng Congqian Tsuchiya Koichi 《金属学报》2018,(9):1262-1272
beta-type alloys have a wide application prospect in aerospace, biomedical and marine engineering and other fields, owing to their high specific strength, good corrosion resistance and low elastic modulus. Their yield strength and uniform elongation are affected by the second phase precipitation, plastic deformation mode and interstitial element, especially the oxygen element. In this work, the effect of tensile pre-deformation induced {332}< 113 > twins combined with isothermal w-phase after subsequent ageing on the mechanical properties of beta-type Ti-15Mo alloy with different oxygen contents from 0.1% to 0.5% (mass fraction) was examined by OM, XRD, TEM and DSC, Vickers hardness tester and tensile testing machine. The results indicated that with increasing the oxygen content, the formation of mechanical twins and isothermal omega-phase in the alloy was suppressed, and the effect of pre-deformation induced twins on the precipitation of isothermal omega-phase was negligible. After pre-deformation combined with subsequent ageing, the alloy with low oxygen content had the relatively high yield strength and large uniform elongation, but it with high oxygen content exhibited the brittle fracture. A good combination of strength with ductility in the alloy with low oxygen content was contributed to the twinning and dislocation slip coupled deformation. The high yield strength was mainly dominated by the dislocation slip, and the large uniform elongation was due to the static and dynamic grain refinement effects, which were caused by the pre-deformation induced twins and subsequent twinning deformation, respectively. Through utilizing the alloying element of oxygen effectively, and changing the plastic deformation mode and phase precipitation behavior based on the reasonable process of pre-deformation and heat treatment, the combination of strength and ductility can be controlled in a large range for the beta-type titanium alloys. 相似文献
12.
利用OM、SEM、TEM及物理化学相等方法研究了时效温度变化对直接淬火Ni-Cr-Mo-V-Cu低合金钢组织及力学性能的影响,同时在具有最佳强韧性匹配的时效态试样中建立了屈服强度模型。Ni-Cr-Mo-V-Cu钢的直接淬火组织为马氏体和少量贝氏体组成的混合组织。直接淬火Ni-Cr-Mo-V-Cu钢在400~600 ℃范围内的不同温度时效处理后,其强度及维氏硬度表现出典型的欠时效阶段、峰时效阶段及过时效阶段。试验钢位错回复程度、MC及富铜粒子的析出、bcc铁基体中固溶元素的脱溶等因素随时效温度的变化是时效态试验钢表现出上述3个阶段的重要原因。时效态试验钢的断后伸长率大体随时效温度的提高而改善。过时效态试验钢的-20 ℃冲击性能则随着时效温度的升高而提高。直接淬火试验钢在600 ℃时效处理时获得优越的强韧性匹配,MC及富铜粒子所提供的总析出强化增量约为240 MPa。 相似文献
13.
14.
Sushanta Kumar PanigrahiR. Jayaganthan 《Journal of Alloys and Compounds》2011,509(40):9609-9616
The effect of ageing on mechanical properties and microstructural characteristics of a precipitation hardenable Al 7075 alloy subjected to rolling at liquid nitrogen temperature and room temperature are has been investigated in the present work employing hardness measurements, tensile test, XRD, DSC, and TEM. The solution-treated bulk Al 7075 alloy was subjected to cryorolling and room temperature rolling to refine grain structures and subsequently ageing treatment to simultaneously improve the strength and ductility. The solution treatment combined with cryorolling up to a true rolling strain of 2.3 followed by low temperature ageing at 100 °C for 45 h has been found to be the optimum processing condition to obtain fine grained microstructure with improved tensile strength (642 MPa) and good tensile ductility (9.5%) in the Al 7075 alloy. The combined effect of suppression of dynamic recovery, partial grain refinement, partial recovery, solid solution strengthening, dislocation hardening, and precipitation hardening are responsible for the significant improvement strength-ductility combination in the cryorolled Al 7075 alloy subjected to peak ageing treatment. The cryorolled and room temperature rolled Al 7075 alloy, upon subjecting to peak ageing treatment, have shown higher strength and ductility in the former than the latter. It is due to presence of high density of nanosized precipitates in the peak aged cryorolled sample. 相似文献
15.
This work is devoted to the effect of processes initiated by the combined action of aging (A) and accumulative roll bonding (ARB) on the evolution of the microstructure and the mechanical characteristics of an Al–0.2 wt % Zr alloy. Upon solution treatment (ST), followed by aging at temperatures of 350 and 450°C, the specimens were subjected to deformation to a degree of deformation of 80% using ARB. The evolution of the microstructure was examined using atomic force microscopy and the mechanical characteristics of the specimens were determined using tensile tests and Vickers microhardness measurements. The results have shown that, upon ten ARB cycles, the grain size decreased to 0.3, 0.4, and 0.32 μm in the specimens subjected to ST followed by ARB (ST–ARB), ST followed by A at a temperature of 350°C and ARB (350°C–A–ARB), and ST followed by A at a temperature of 450°C and ARB (450°C–A–ARB), respectively. This study has also shown that the combined use of preliminary A and subsequent ARB holds promise in enhancing the mechanical characteristics of the alloy due to precipitates that appear in the course of annealing. Fracture surfaces of the rolled specimens subjected to the tensile tests were examined using scanning electron microscopy. The results of these examinations have shown that in the specimens subjected to ST followed by ARB brittle fracture has been observed at the stage of the final ARB cycles, while in the A–ARB specimens cleavage facets (sites of fracture over the cleavage plane) and river lines have appeared on the fracture surfaces. 相似文献
16.
Effect of precipitates on microstructures and properties of forged Mg-10Gd-2Y-0.5Zn-0.3Zr alloy during ageing process 总被引:1,自引:0,他引:1
The precipitate behavior during forging and ageing process of Mg-10Gd-2Y-0.5Zn-0.3Zr alloy has been investigated by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The mechanical properties of the alloy after forging and ageing process have been evaluated using Vickers hardness and room-temperature tensile tests. The results show that precipitation of 14H-type long period stacking order (LPSO) phase is the main strengthening phase in the as-forged alloy. The LPSO phase and refinement of grains contribute to the strength improvement of the alloy after forging process. The optimal mechanical properties of the alloy are obtained when it is aged at 200 °C for 60 h, which mainly owes to the precipitation of large amounts of β′ and 14H-type LPSO phases on the α-Mg matrix. The growth of secondary phases, widening of soft precipitate free zones and coarsening of grains during subsequent ageing process at higher temperature lead to the decrease of mechanical properties of the alloy. 相似文献
17.
Recently, some side effects of Pd, such as allergies, were found, and the risk of using Pd in dental casting alloys was raised.
The purpose of the present investigation is to report a Pd-free high gold alloy for porcelain bonding. Emphasis is put on
the effect of heat treatment on the mechanical properties of the alloy. The gold alloy was based on the ternary system of
Au−Pt−Zn with a nominal composition of 86Au-11Pt-1.5Zn-0.5In-0.7Rh-0.2Fe-0.1Ir (wt.%). Both the hardness and tensile strength
of the as-cast alloy can be significantly improved by heat treatment at 980°C for 15 min followed by bench cooling, but can't
be raised by conventional solution treatment followed by ageing. The strengthening could be attributed to homogenization of
microstructure and alloying elements and precipitation of new fine particles. It is suggested that the cast framework of the
present new Pd-free alloy could be heat treated before actual firing, and this will improve the processing properties of the
alloy during firing. 相似文献
18.
通过析出硬化提高Al?Si?Cu合金的力学性能.这些合金对时效硬化的反应非常缓慢.为了解决这一问题,在Al?10.5Si?3.4Cu合金中分别加入0.2%、0.4%和0.7%(质量分数)的镁.该新型合金在固溶处理阶段经过两种不同的析出硬化过程.结果表明,添加不同含量的镁可加速该合金对时效处理的响应,提高其硬度和强度.双... 相似文献
19.
20.
Roohollah Jamaati Sajjad Amirkhanlou Mohammad Reza Toroghinejad Behzad Niroumand 《Journal of Materials Engineering and Performance》2012,21(7):1249-1253
Accumulative roll bonding (ARB) and continual annealing and roll-bonding (CAR) processes were used in this study for improving the microstructure and mechanical properties of the A356/10?vol.% SiC metal matrix composite (MMC) produced by semi-solid metal processing (SSM). The results showed that using the ARB and CAR processes led to the following points: (a) the uniformity of the silicon and silicon carbide in the aluminum matrix improved, (b) the Si particles became finer and more spheroidal in appearance, (c) the porosity disappeared, (d) the bonding quality between the reinforcement and the matrix improved, (e) the particle-free zone disappeared, and therefore (f) the tensile strength (TS), elongation, and formability index of the MMC samples improved. However, it was found that the CAR process is a better method for improvement of microstructure and mechanical properties of as-cast MMC compared to ARB process. 相似文献