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热压形变参数对AZ31镁合金接头微观组织和力学性能的影响 被引量:2
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作者 初雅杰 李晓泉 +2 位作者 吴申庆 徐振钦 杜舜尧 《材料工程》 EI CAS CSCD 北大核心 2014年第6期35-39,共5页
采用与母材同质的焊丝对AZ31镁合金板材进行手工钨极氩弧焊,利用真空热压炉及专门设计的夹装模具对焊接接头分别在250,300,350,400℃,应变速率为0.001s-1进行真空热压试验,通过电子拉伸试验仪、光学显微镜(OM)及扫描电镜(SEM)技术,研究... 采用与母材同质的焊丝对AZ31镁合金板材进行手工钨极氩弧焊,利用真空热压炉及专门设计的夹装模具对焊接接头分别在250,300,350,400℃,应变速率为0.001s-1进行真空热压试验,通过电子拉伸试验仪、光学显微镜(OM)及扫描电镜(SEM)技术,研究镁合金焊接接头的力学性能和组织演化规律。结果表明:随着热压温度的升高,接头抗拉强度和伸长率不断增大,在350℃时,接头表现出最大的抗拉强度228MPa和伸长率10.2%,400℃时,强度和伸长率有所降低。在该工艺过程中,随着变形温度的升高,接头组织再结晶现象越来越明显,350℃时出现较多的动态再结晶核心和再结晶小晶粒,平均晶粒尺寸由46μm细化至16μm左右,随着温度的升高,动态再结晶晶粒数量逐渐增加,400℃时,晶粒尺寸有所长大,平均晶粒尺寸为26μm,分布较均匀。 展开更多
关键词 AZ31镁合金 热压形变 焊接接头 显微组织
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SIMA法处理AZ61热、冷压形变及半固态等温组织的比较研究 被引量:4
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作者 陈国平 周天瑞 +2 位作者 闫洪 张发云 刘宏 《塑性工程学报》 CAS CSCD 北大核心 2008年第1期112-117,共6页
研究镁合金AZ61在SIMA法处理过程中压缩形变条件下,冷或热形变方式、形变率以及相应的等温热处理参数等对组织的影响规律。在同等热处理条件下,进行冷或热形变方式两套实验方案比较研究。结果表明,SI-MA法中,镁合金AZ61预变形采用热变... 研究镁合金AZ61在SIMA法处理过程中压缩形变条件下,冷或热形变方式、形变率以及相应的等温热处理参数等对组织的影响规律。在同等热处理条件下,进行冷或热形变方式两套实验方案比较研究。结果表明,SI-MA法中,镁合金AZ61预变形采用热变形或冷变形均可得到细小非枝晶组织,虽演变机理不同,但在储存能趋于饱和之前,增加镁合金试样的热形变率或冷形变率,可以使热处理后非枝晶化效果和质量提高,但必须选择适当的等温热处理温度和保温时间。 展开更多
关键词 SIMA法 镁合金 半固态组织 热压形变 形变 形变
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热-压形变对超高压水压泵柱塞副间隙泄漏的影响 被引量:2
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作者 赵晶 冀宏 +1 位作者 刘银水 张建军 《兰州理工大学学报》 CAS 北大核心 2022年第2期43-48,共6页
柱塞副间隙的泄漏是影响柱塞泵容积效率的主要因素,超高压工况下柱塞副微米间隙的热-压形变不可忽略.利用流-固-热耦合方法,建立柱塞副压形变主导模型和热-压耦合形变模型,对单边间隙高度5μm的柱塞副二维轴对称模型中的压差流动进行仿... 柱塞副间隙的泄漏是影响柱塞泵容积效率的主要因素,超高压工况下柱塞副微米间隙的热-压形变不可忽略.利用流-固-热耦合方法,建立柱塞副压形变主导模型和热-压耦合形变模型,对单边间隙高度5μm的柱塞副二维轴对称模型中的压差流动进行仿真计算.结果表明:当柱塞副入口压力为110 MPa时,在间隙入口受压形变占主导,单边间隙增大4μm以上,在间隙出口热形变占主导,单边间隙减小1.1μm;压形变主导模型计算所得柱塞副间隙泄漏量为柱塞副无形变时的4倍;热-压耦合形变模型计算所得柱塞副间隙泄漏量是柱塞副无形变时的1.3倍.研究结果为准确预测超高压水压泵柱塞副的间隙泄漏流量提供方法. 展开更多
关键词 超高 柱塞副间隙 形变 -耦合形变 间隙泄漏占比
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Hot deformation behavior of Al-9.0Mg-0.5Mn-0.1Ti alloy based on processing maps 被引量:7
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作者 范才河 彭英彪 +2 位作者 阳海棠 周伟 严红革 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第2期289-297,共9页
Hot deformation behavior of extrusion preform of the spray-formed Al-9.0Mg-0.5Mn-0.1Ti alloy was studied using hot compression tests over deformation temperature range of 300-450 ℃ and strain rate range of 0.01... Hot deformation behavior of extrusion preform of the spray-formed Al-9.0Mg-0.5Mn-0.1Ti alloy was studied using hot compression tests over deformation temperature range of 300-450 ℃ and strain rate range of 0.01-10 s-1. On the basis of experiments and dynamic material model, 2D processing maps and 3D power dissipation maps were developed for identification of exact instability regions and optimization of hot processing parameters. The experimental results indicated that the efficiency factor of energy dissipate (η) lowered to the minimum value when the deformation conditions located at the strain of 0.4, temperature of 300 ° C and strain rate of 1 s-1. The softening mechanism was dynamic recovery, the grain shape was mainly flat, and the portion of high angle grain boundary (〉15°) was 34%. While increasing the deformation temperature to 400 ° C and decreasing the strain rate to 0.1 s-1, a maximum value of η was obtained. It can be found that the main softening mechanism was dynamic recrystallization, the structures were completely recrystallized, and the portion of high angle grain boundary accounted for 86.5%. According to 2D processing maps and 3D power dissipation maps, the optimum processing conditions for the extrusion preform of the spray-formed Al?9.0Mg?0.5Mn?0.1Ti alloy were in the deformation temperature range of 340-450 ° C and the strain rate range of 0.01-0.1 s-1 with the power dissipation efficiency range of 38%?43%. 展开更多
关键词 spray forming Al-9.0Mg-0.5Mn-0.1Ti alloy hot compressing deformation processing map dynamic recrystallization
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Hot deformation behavior of as-quenched 7005 aluminum alloy 被引量:7
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作者 王明亮 金培鹏 +1 位作者 王金辉 韩丽 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第9期2796-2804,共9页
The compressive deformation behavior of as-quenched 7005 aluminum alloy was investigated at the temperature ranging from 250 °C to 450 °C and strain rate ranging from 0.0005 s-1 to 0.5 s^-1 on Gleeble-1500 t... The compressive deformation behavior of as-quenched 7005 aluminum alloy was investigated at the temperature ranging from 250 °C to 450 °C and strain rate ranging from 0.0005 s-1 to 0.5 s^-1 on Gleeble-1500 thermal-simulation machine. Experimental results show that the flow stress of as-quenched 7005 alloy is affected by both deformation temperature and strain rate, which can be represented by a Zener-Hollomon parameter in an exponent-type equation. By comparing the calculated flow stress and the measured flow stress, the results show that the calculated flow stress agrees well with the experimental result. Based on a dynamic material model, the processing maps were constructed for the strains of 0.1, 0.3 and 0.5. The maps and microstructural examination revealed that the optimum hot working domain is 270-340 °C, 0.05-0.5 s^-1 with the reasonable dynamic recrystallization. The instability domain exhibits adiabatic shear bands and flow localization, which should be avoided during hot working in order to obtain satisfactory properties. 展开更多
关键词 7005 alloy hot compression deformation constitutive equation processing map
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Processing map and hot deformation mechanism of novel nickel-free white copper alloy 被引量:7
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作者 刘娜 李周 +2 位作者 李灵 刘斌 徐根应 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第11期3492-3499,共8页
Hot compression test of a novel nickel-free white alloy Cu?12Mn?15Zn?1.5Al?0.3Ti?0.14B?0.1Ce (mass fraction, %) was conducted on a Gleeble?1500 machine in the temperature range of 600?800 °C and the strain rate r... Hot compression test of a novel nickel-free white alloy Cu?12Mn?15Zn?1.5Al?0.3Ti?0.14B?0.1Ce (mass fraction, %) was conducted on a Gleeble?1500 machine in the temperature range of 600?800 °C and the strain rate range of 0.01?10 s?1. The constitutive equation and hot processing map of the alloy were built up according to its hot deformation behavior and hot working characteristics. The deformation activation energy of the alloy is 203.005 kJ/mol. An instability region appears in the hot deformation temperature of 600?700 °C and the strain rate range of 0.32?10 s?1 when the true strain of the alloy is up to 0.7. Under the optimal hot deformation condition of 800 °C and 10 s?1 the prepared specimen has good surface quality and interior structure. The designed nickel-free alloy has very similar white chromaticity with the traditional white copper alloy (Cu?15Ni?24Zn?1.5Pb), and the color difference between them is less than 1.5, which can hardly be distinguished by human eyes. 展开更多
关键词 Ni-free white copper alloy hot compression deformation constitutive equation processing map
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Flow behavior and processing map of PM Ti-47Al-2Cr-0.2Mo alloy 被引量:4
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作者 李慧中 曾敏 +2 位作者 梁霄鹏 李洲 刘咏 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第4期754-760,共7页
The flow stress features of PM Ti-47Al-2Cr-0.2Mo alloy were studied by isothermal compression in the temperature range from 1000 to 1150 °C with strain rates of 0.001-1 s-1 on Gleeble-1500 thermo-simulation machi... The flow stress features of PM Ti-47Al-2Cr-0.2Mo alloy were studied by isothermal compression in the temperature range from 1000 to 1150 °C with strain rates of 0.001-1 s-1 on Gleeble-1500 thermo-simulation machine.The results show that the deformation temperature and strain rate have obvious effects on the flow characteristic,and the flow stress increases with increasing strain rate and decreasing temperature.The processing maps under different deformation conditions were established.The processing maps of this alloy are sensitive to strains.The processing map at the strain of 0.5 exhibits two suitable deformation domains of 1000-1050 °C at 0.001-0.05 s-1 and 1050-1125 °C at 0.01-0.1 s-1.The optimum parameters for hot working of the alloy are deformation temperature of 1000 °C and strain rate of 0.001 s-1 according to the processing map and microstructure at true strain of 0.5. 展开更多
关键词 powder metallurgy TiAl based alloy hot compression deformation processing map
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Effect of strain rate and deformation temperature on strain hardening and softening behavior of pure copper 被引量:4
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作者 黄树海 舒大禹 +1 位作者 胡传凯 朱世凤 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第4期1044-1054,共11页
The effects of the deformation temperature and the strain rate on the hot deformation behavior of pure copper were investigated based on compression tests. The expressions of strain hardening rate, dynamic recrystalli... The effects of the deformation temperature and the strain rate on the hot deformation behavior of pure copper were investigated based on compression tests. The expressions of strain hardening rate, dynamic recrystallization critical stress, saturated stress, dynamic recovery volume fraction and dynamic recrystallization volume fraction were determined. According to the processing map, the instability regions occur in regions of 400?450 °C, 0.001?0.05 s?1 and 450?750 °C, 0.05?1 s?1. The deformation mechanism in the stability region is dynamic recrystallization. The flow stress was predicted. The results also show that the true stress–true strain curves predicted by the extracted model are in good agreement with the experimental results. 展开更多
关键词 COPPER hot compression deformation strain hardening strain softening
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Hot deformation behavior and processing map of Cu-Ni-Si-P alloy 被引量:6
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作者 张毅 刘平 +3 位作者 田保红 刘勇 李瑞卿 许倩倩 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第8期2341-2347,共7页
The high-temperature deformation behavior of Cu-Ni-Si-P alloy was investigated by using the hot compression test in the temperature range of 600-800 ℃ and strain rate of 0.01-5 s-1. The hot deformation activation ene... The high-temperature deformation behavior of Cu-Ni-Si-P alloy was investigated by using the hot compression test in the temperature range of 600-800 ℃ and strain rate of 0.01-5 s-1. The hot deformation activation energy, Q, was calculated and the hot compression constitutive equation was established. The processing maps of the alloy were constructed based on the experiment data and the forging process parameters were then optimized based on the generated maps for forging process determination. The flow behavior and the microstructural mechanism of the alloy were studied. The flow stress of the Cu-Ni-Si-P alloy increases with increasing strain rate and decreasing deformation temperature, and the dynamic recrystallization temperature of alloy is around 700 ℃. The hot deformation activation energy for dynamic recrystallization is determined as 485.6 kJ/mol. The processing maps for the alloy obtained at strains of 0.3 and 0.5 were used to predict the instability regimes occurring at the strain rate more than 1 s-1 and low temperature (〈650 ℃). The optimum range for the alloy hot deformation processing in the safe domain obtained from the processing map is 750-800 ℃ at the strain rate of 0.01-0.1 s i The characteristic microstructures predicted from the processing map agree well with the results of microstructural observations. 展开更多
关键词 Cu-Ni-Si-P alloy hot compression deformation dynamic recrystallization constitutive equation processing maps
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Hot deformation behavior of Al-Zn-Mg-Cu-Zr aluminum alloys during compression at elevated temperature 被引量:17
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作者 张辉 金能萍 陈江华 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第3期437-442,共6页
The hot compression tests of Al-Zn-Mg-Cu-Zr aluminum alloys (7056 alloy and 7150 alloy) were performed in a temperature range from 300 to 450 °C and at strain rate range from 0.01 to 10 s-1. The results show th... The hot compression tests of Al-Zn-Mg-Cu-Zr aluminum alloys (7056 alloy and 7150 alloy) were performed in a temperature range from 300 to 450 °C and at strain rate range from 0.01 to 10 s-1. The results show that the true stress-true strain curves exhibit a peak stress at a critical strain, then the flow stresses decrease monotonically until high strains, showing a dynamic flow softening. The peak stresses depend on the temperature compensated strain rate, which can be represented by the Zener-Hollomon parameter Z in the hyperbolic-sine equation with hot deformation activation energy of 244.64 kJ/mol for 7056 alloy and 229.75 kJ/mol for 7150 alloy, respectively, while the peak stresses for the former are lower than those for the latter under the similar compression condition. The deformed microstructures consist of a great amount of precipitates within subgrains in the elongated grains at high Z value and exhibit well formed subgrains in the recrystallized grains at low Z value. The smaller subgrains and greater density of fine precipitates in 7150 alloy are responsible for the high peak stresses because of the substructural strengthening and precipitating hardening compared with 7056 alloy. 展开更多
关键词 Al-Zn-Mg-Cu-Zr aluminum alloys flow stress dynamic recrystallization dynamic precipitation
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Flow instability criteria in processing map of superalloy GH79 被引量:4
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作者 周舸 丁桦 +2 位作者 曹富荣 韩寅奔 张北江 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第7期1575-1581,共7页
Hot compression tests were conducted on a Gleeble-1500D thermal simulating tester.Based on the deformation behavior and microstructural evolution of superalloy GH79,different types of instability criteria of PRASAD,GE... Hot compression tests were conducted on a Gleeble-1500D thermal simulating tester.Based on the deformation behavior and microstructural evolution of superalloy GH79,different types of instability criteria of PRASAD,GEGEL,MALAS,MURTY and SEMIATIN were compared,and the physical significance of parameters was analyzed.Meanwhile,the processing maps with different instability criteria were obtained.It is shown that instability did not occur when average power dissipation rate was larger than 60%in the temperature range of 900-930°C and 960-1080°C,corresponding to the strain rate range of 5×10 -4 -1.8×10 -1 s -1 and 5×10 -4 -1.5×10 -1 s -1 ,respectively.The two domains are appropriate for the processing deformation of superalloy GH79. 展开更多
关键词 nickel-based superalloy hot compression flow instability criterion processing map
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Hot compression behavior and deformation microstructure of Mg-6Zn-1Al-0.3Mn magnesium alloy 被引量:4
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作者 史宝良 罗天骄 +1 位作者 王晶 杨院生 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第9期2560-2567,共8页
The hot compression behavior of a wrought Mg-6Zn-1Al-0.3Mn magnesium alloy was investigated using Gleeble test at 200-400 °C with strain rates ranging from 0.01 to 7 s-1. The true stress-strain curves show that t... The hot compression behavior of a wrought Mg-6Zn-1Al-0.3Mn magnesium alloy was investigated using Gleeble test at 200-400 °C with strain rates ranging from 0.01 to 7 s-1. The true stress-strain curves show that the hot deformation behavior significantly depends on the deformation temperature and strain rate. The calculated hot deformation activation energy Q is 166 kJ/mol with a stress exponent n=5.99, and the constitutive equation is deduced to be ε& =3.16×1013[sinh(0.010σ)]5.99exp [-1.66×105/(RT)]· Deformation microstructure shows that the incompletely dynamically recrystallized grains can be found at grain boundaries and twins with the strain rates ranging from 0.01 to 1 s^-1 at 250 °C, and completely dynamic recrystallization occurs when the temperature is 350 °C or above during hot compression, the size of recrystallized grains decreases with the increment of the strain rate at the same temperature. The relatively suitable deformation condition is considered temperature 330-400 °C and strain rate of 0.01-0.03 s-1, and temperature of 350 °C and strain rate of 1 s-1. 展开更多
关键词 wrought magnesium alloy hot compression STRESS STRAIN RECRYSTALLIZATION
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Influence of pre-strain and heat treatment on subsequent deformation behavior of extruded AZ31 Mg alloy 被引量:2
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作者 陈红兵 刘天模 +2 位作者 卢立伟 何杰军 翟彦博 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第11期3604-3610,共7页
Pre-compression and heat treatment were performed on an extruded AZ31 Mg alloy,and their effects on subsequent deformation behavior were investigated.The results show that at low temperature annealing(170 ℃ for 4 h),... Pre-compression and heat treatment were performed on an extruded AZ31 Mg alloy,and their effects on subsequent deformation behavior were investigated.The results show that at low temperature annealing(170 ℃ for 4 h),the extruded samples with and without annealing exhibit a nearly equivalent yield stress(~148 MPa) because their microstructures are nearly unchanged.However,under the same annealing condition,the yield stress of sample with pre-twinning and subsequent annealing(~225 MPa) is higher than that of the pre-twinned one(~200 MPa).The former sample presents a hardening effect because the solute atoms segregated on twin boundaries lead to a strengthening effect.The pre-twinned sample annealed at 400 ℃ for 1 h shows a higher ultimate elongation(~28%) than the pre-twinned one(~15%),but its yield stress(~125 MPa) is much lower than that of the pre-twinned one(~200 MPa). 展开更多
关键词 AZ31 Mg alloys TWINNING annealing hardening pre-compression heat treatment deformation
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Effect of deformation temperature on microstructure and mechanical properties of 7055 aluminum alloy after heat treatment 被引量:5
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作者 闫亮明 沈健 +1 位作者 李周兵 李俊鹏 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第3期625-630,共6页
The multi-pass hot compression test of 7055 aluminum alloy was performed at different temperatures and then the samples were heat treated by T6 heat treatment.The compressed samples were analyzed by OM and TEM.The res... The multi-pass hot compression test of 7055 aluminum alloy was performed at different temperatures and then the samples were heat treated by T6 heat treatment.The compressed samples were analyzed by OM and TEM.The results reveal that the average aspect ratio of the grains in the specimens compressed first decreases and then increases,the dislocation density decreases and subgrain diameter increases with the increase of deformation temperature.The effects of deformation temperature on the microstructure and mechanical properties of 7055 aluminum alloy after heat treatment were investigated by means of OM and mechanical property test.The results indicate that the deformation temperature significantly influences microstructure and mechanical property of 7055 aluminum alloy.The volume fraction of recrystallization grains presents a "fall-rise" pattern with the deformation temperature rising.The mechanical properties get better when the volume fraction of recrystallization grains decreases.Moreover,the volume fraction of recrystallization grain has a minimum value,appropriately 45%,and the sample exhibits the highest strength and elongation at the deformation temperature of 400 ℃. 展开更多
关键词 7055 aluminum alloy hot deformation temperature hot compression RECRYSTALLIZATION
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Fabrication of flatten grooved-sintered wick heat pipe 被引量:1
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作者 蒋乐伦 汤勇 +2 位作者 周伟 蒋琳珍 陆龙生 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第9期2714-2725,共12页
With the rapid rising of heat flux and reduction of heat dissipating space of microelectronic devises, flattened sintered heat pipe has become an ideal conducting element of use in the electronic cooling field. A manu... With the rapid rising of heat flux and reduction of heat dissipating space of microelectronic devises, flattened sintered heat pipe has become an ideal conducting element of use in the electronic cooling field. A manufacturing technology named phase change flattening process is presented to fabricate the flattened grooved-sintered wick heat pipe (GSHP for short). Deformation geometry of flattened GSHP and the elasto-plastic deformation of flattening process are analyzed theoretically and verified by experiments. The results show that the vapor pressure inside sintered heat pipe during flattening process is determined by the saturated vapor pressure equation; the width and vapor area of flattened heat pipe change greatly as the flattening proceeds; the maximum equivalent strain distributes at the interface between wick and vapor in the fiat section; the buckling phenomenon can be well eliminated when the flattening temperature reaches 480 K; phase change flattening punch load increases with flattening temperature and displacement. 展开更多
关键词 heat pipe WICK FLATTENING elasto-plastic deformation BUCKLING vapor pressure
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Effects of hot compression on carbide precipitation behavior of Ni-20Cr-18W-1Mo superalloy
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作者 韩寅奔 薛祥义 +2 位作者 张铁邦 胡锐 李金山 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第11期2883-2891,共9页
The effect of hot compression on the grain boundary segregation and precipitation behavior of M6C carbide in theNi-20Cr-18W-1Mo superalloy was investigated by thermomechanical simulator, scanning electronic microscope... The effect of hot compression on the grain boundary segregation and precipitation behavior of M6C carbide in theNi-20Cr-18W-1Mo superalloy was investigated by thermomechanical simulator, scanning electronic microscope (SEM) and X-raydiffraction (XRD). Results indicate that the amount of M6C carbides obviously increases in the experimental alloy after hotcompression. Composition analyses reveal that secondary M6C carbides at grain boundaries are highly enriched in tungsten.Meanwhile, the secondary carbide size of compressive samples is 3?5 μm in 10% deformation degree, while the carbide size ofundeformed specimens is less than 1 μm under aging treatment at 900 and 1000 ℃. According to the thermodynamic calculationresults, the Gibbs free energy of γ-matrix and carbides decreases with increase of the compression temperature, and the W-rich M6Ccarbide is more stable than Cr-rich M23C6. Compared with the experimental results, it is found that compressive stress accelerates theW segregation rate in grain boundary region, and further rises the rapid growth of W-rich M6C as compared with the undeformedone. 展开更多
关键词 Ni-20Cr-18W-1Mo superalloy hot compression grain boundary segregation carbide precipitation
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High temperature deformation behavior and optimization of hot compression process parameters in TC11 titanium alloy with coarse lamellar original microstructure 被引量:4
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作者 鲁世强 李鑫 +2 位作者 王克鲁 董显娟 傅铭旺 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第2期353-360,共8页
The high temperature deformation behaviors of α+β type titanium alloy TC11 (Ti-6.5Al-3.5Mo-1.5Zr-0.3Si) with coarse lamellar starting microstructure were investigated based on the hot compression tests in the tem... The high temperature deformation behaviors of α+β type titanium alloy TC11 (Ti-6.5Al-3.5Mo-1.5Zr-0.3Si) with coarse lamellar starting microstructure were investigated based on the hot compression tests in the temperature range of 950-1100 ℃ and the strain rate range of 0.001-10 s-1. The processing maps at different strains were then constructed based on the dynamic materials model, and the hot compression process parameters and deformation mechanism were optimized and analyzed, respectively. The results show that the processing maps exhibit two domains with a high efficiency of power dissipation and a flow instability domain with a less efficiency of power dissipation. The types of domains were characterized by convergence and divergence of the efficiency of power dissipation, respectively. The convergent domain in a+fl phase field is at the temperature of 950-990 ℃ and the strain rate of 0.001-0.01 s^-1, which correspond to a better hot compression process window of α+β phase field. The peak of efficiency of power dissipation in α+β phase field is at 950 ℃ and 0.001 s 1, which correspond to the best hot compression process parameters of α+β phase field. The convergent domain in β phase field is at the temperature of 1020-1080 ℃ and the strain rate of 0.001-0.1 s^-l, which correspond to a better hot compression process window of β phase field. The peak of efficiency of power dissipation in ℃ phase field occurs at 1050 ℃ over the strain rates from 0.001 s^-1 to 0.01 s^-1, which correspond to the best hot compression process parameters of ,8 phase field. The divergence domain occurs at the strain rates above 0.5 s^-1 and in all the tested temperature range, which correspond to flow instability that is manifested as flow localization and indicated by the flow softening phenomenon in stress-- strain curves. The deformation mechanisms of the optimized hot compression process windows in a+β and β phase fields are identified to be spheroidizing and dynamic recrystallizing controlled by self-diffusion mechanism, respectively. The microstructure observation of the deformed specimens in different domains matches very well with the optimized results. 展开更多
关键词 titanium alloy coarse lamellar microstructure high temperature deformation behavior processing map hot compression process parameter optimization
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Flow stress behavior and processing map of extruded 7075Al/SiC particle reinforced composite prepared by spray deposition during hot compression 被引量:2
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作者 吴红丹 张辉 +1 位作者 陈爽 傅定发 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2015年第3期692-698,共7页
Hot compression tests of the extruded 7075Al/15%SiC (volume fraction) particle reinforced composite prepared by spray deposition were performed on Gleeble?1500 system in the temperature range of 300?450 °C and st... Hot compression tests of the extruded 7075Al/15%SiC (volume fraction) particle reinforced composite prepared by spray deposition were performed on Gleeble?1500 system in the temperature range of 300?450 °C and strain rate range of 0.001?1 s?1. The results indicate that the true stress?true strain curve almost exhibits rapid flow softening phenomenon without an obvious work hardening, and the stress decreases with increasing temperature and decreasing strain rate. Moreover, the stress levels are higher at temperature below 400 °C but lower at 450 °C compared with the spray deposited 7075Al alloy. Superplastic deformation characteristics are found at temperature of 450 °C and strain rate range of 0.001?0.1 s?1 with corresponding strain rate sensitivity of 0.72. The optimum parameters of hot working are determined to be temperature of 430?450 °C and strain rate of 0.001?0.05 s?1 based on processing map and optical microstructural observation. 展开更多
关键词 7075 Al SIC particle-reinforced composite hot compression deformation flow stress processing map superplastic deformation
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Flow behavior of Al-6.2Zn-0.70Mg-0.30Mn-0.17Zr alloy during hot compressive deformation based on Arrhenius and ANN models 被引量:16
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作者 Jie YAN Qing-lin PAN +1 位作者 An-de LI Wen-bo SONG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第3期638-647,共10页
The hot deformation behavior of Al?6.2Zn?0.70Mg?0.30Mn?0.17Zr alloy was investigated by isothermal compressiontest on a Gleeble?3500machine in the deformation temperature range between623and773K and the strain rate ra... The hot deformation behavior of Al?6.2Zn?0.70Mg?0.30Mn?0.17Zr alloy was investigated by isothermal compressiontest on a Gleeble?3500machine in the deformation temperature range between623and773K and the strain rate range between0.01and20s?1.The results show that the flow stress decreases with decreasing strain rate and increasing deformation temperature.Basedon the experimental results,Arrhenius constitutive equations and artificial neural network(ANN)model were established toinvestigate the flow behavior of the alloy.The calculated results show that the influence of strain on material constants can berepresented by a6th-order polynomial function.The ANN model with16neurons in hidden layer possesses perfect performanceprediction of the flow stress.The predictabilities of the two established models are different.The errors of results calculated by ANNmodel were more centralized and the mean absolute error corresponding to Arrhenius constitutive equations and ANN model are3.49%and1.03%,respectively.In predicting the flow stress of experimental aluminum alloy,the ANN model has a betterpredictability and greater efficiency than Arrhenius constitutive equations. 展开更多
关键词 aluminum alloy hot compressive deformation flow stress constitutive equation artificial neural network model
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Compressive response and microstructural evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite 被引量:12
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作者 Han WANG Hai-ming ZHANG +2 位作者 Zhen-shan CUI Zhe CHEN Dong CHEN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第5期1235-1248,共14页
The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation... The hot forming behavior,failure mechanism,and microstructure evolution of in-situ TiB_(2)particle-reinforced 7075 aluminum matrix composite were investigated by isothermal compression test under different deformation conditions of deformation temperatures of 300−450℃ and strain rates of 0.001^(−1)s^(−1).The results demonstrate that the failure behavior of the composite exhibits both particle fracture and interface debonding at low temperature and high strain rate,and dimple rupture of the matrix at high temperature and low strain rate.Full dynamic recrystallization,which improves the composite formability,occurs under conditions of high temperature(450℃)and low strain rate(0.001 s^(−1));the grain size of the matrix after hot compression was significantly smaller than that of traditional 7075Al and ex-situ particle reinforced 7075Al matrix composite.Based on the flow stress curves,a constitutive model describing the relationship of the flow stress,true strain,strain rate and temperature was proposed.Furthermore,the processing maps based on both the dynamic material modeling(DMM)and modified DMM(MDMM)were established to analyze flow instability domain of the composite and optimize hot forming processing parameters.The optimum processing domain was determined at temperatures of 425−450℃ and strain rates of 0.001−0.01 s^(−1),in which the fine grain microstructure can be gained and particle crack and interface debonding can be avoided. 展开更多
关键词 in-situ TiB2 particles aluminum matrix composite hot compression deformation particle fracture interface debonding dynamic recrystallization
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