2524铝合金的热压缩变形行为

利用Gleeble-1500热模拟实验机,对2524铝合金进行高温等温压缩试验,实验变形温度为300～500℃,应变速率为0.01～10 s-1的条件下,研究了2524铝合金的流变变形行为。结果表明:合金流变应力的大小跟变形温度和应变速率有很大关联,2524铝合金真应力-应变曲线中,流变应力开始随应变增加而增大,达到峰值后趋于平稳,表现出动态回复特征,而峰值流变应力随变形温度的降低和应变速率的升高而增大;在流变速率ε为10 s-1,变形温度300℃以上时,应力出现锯齿波动,合金表现出动态再结晶特征。采用温度补偿应变速率Zener-Hollomon参数值来描述2524铝合金在高温塑性变形流变行为时,其变形激活能Q为216.647 kJ/mol。在等温热压缩形变中,合金可加工条件为:高应变速率(>0.5 s-1)或低应变速率(0.01 s-1～0.02 s-1)、高应变温度(440℃～500℃)。     

5A01铝合金高温压缩流变行为

采用Gleeble-1500热模拟机高温压缩试验,研究5A01铝合金在应变速牢为0.01～1s-1、变形温度为350～450℃条件下的流变行为,并利用光学显微镜分析合金在不同压缩条件下的组织形貌特征.结果表明:应变速率和变形温度的变化强烈影响合金流变应力的大小,流变应力随变形温度升高而降低,随应变速率提高而增大.采用双曲正弦形式ARRHENIUS的关系来描述5A01铝合金高温压缩变形时的流变应力行为,获得的材料常数A、α、n和Q分别为0.068 31 s-1、0.009 4 MPa-1、2.708 9和161.14 kJ/mol:在应变速率为0.01 s-1及变形温度低于400℃条件下变形时,5A01铝合金组织为纤维组织,而当变形温度升高到450℃时,再结晶程度很高,出现大量等轴晶.     

5A01铝合金热变形行为和加工图

在Gleeble-1500热模拟机上,对5A01铝合金进行等温热压缩实验,研究该合金在变形温度为350~450℃、应变速率为0.01~1s-1条件下的热变形行为,建立其热加工图。结果表明:5A01铝合金是温度、正应变速率敏感材料,其流变应力随变形温度降低和应变速率升高而增大,利用峰值应力获得的该合金热加工图表明合金热变形存在两个失稳区域,即变形温度为350~390℃,应变速率为0.01~0.2s-1的区域和变形温度为405~450℃,应变速率为0.2~1s-1的区域;本实验条件下最佳加工参数为变形温度450℃,应变速率0.01s-1。     

TiNiFe形状记忆合金热变形行为的研究

针对TiNiFe形状记忆合金,在Gleeble-3500热模拟试验机上对其进行了高温压缩实验,研究了TiNiFe合金在温度为750～1050℃、应变速率为0.01～10.00 s-1条件下的热变形行为。结果表明,流变应力受到变形温度和应变速率的显著影响,在相同变形温度条件下,流变应力随应变速率的提高而增大;在相同应变速率条件下,流变应力随变形温度的升高而降低。并采用双曲正弦模型确定了该合金的应力指数n和变形激活能Q,建立了相应的热变形本构关系。经实验验证,所建立的本构关系能够很好的反映TiNiFe合金的实际热变形行为特征。     

7050高强铝合金高温塑性变形的流变应力研究

通过在Gleeble1500D热模拟试验机上进行等温热压缩试验,研究了7050高强铝合金在变形温度为300～450℃和应变速率为0.01～10s-1条件下的流变应力变化规律,计算推导出包含Arrhenius项的zener-Hollomon参数描述7050合金高温压缩流变行为的表达式.结果表明:应变速率和变形温度对7050合金的流变应力影响显著,流变应力随温度升高而降低,随应变速率的提高而增大;7050合金属于正应变速率敏感材料,合金的形变激活能为163.7425 KJ·mol-1.     

新型Al-Zn-Mg-Cu合金热变形流变应力特征

采用Gleeble-1500热模拟机进行热压缩变形实验,研究了一种新型Al-7.5Zn-1.6Mg-1.4Cu-0.12Zr合金在变形温度为380-460℃、应变速率为0.001～0.1 s-1条件下的流变应力特征,并利用TEM分析了合金在不同变形条件下的组织形貌特征.结果表明,应变速率和变形温度对合金流变应力的大小有显著影响,流变应力随变形温度的升高而降低,随应变速率的提高而增大;合金平均亚晶尺寸随温度补偿应变速率Zener-Hollomon参数的升高而减小.可用Zener-Hollomon咖参数描述该Al-Zn-Mg-Cu合金热变形时的流变应力行为.     

B95оч铝合金的热变形行为研究

采用Gleeble-1500D热模拟试验机进行高温等温压缩变形试验,研究了B95оч铝合金在变形温度为330～450℃、应变速率为0.001～1.000 s-1条件下的热变形行为,并利用金相显微镜(OM)和透射电子显微电镜(TEM)分析了B95оч铝合金在不同变形条件下的组织特征。研究结果表明:变形温度和应变速率对B95оч铝合金的流变应力大小有着显著的影响,合金的流变应力随变形温度的升高而降低,随应变速率的增加而增大。B95оч铝合金在450℃以下热变形过程中析出大量的第二相粒子,并随着温度的降低数量显著增加。B95оч铝合金热变形后平均亚晶尺寸随Zener-Hollomon参数的升高而减小,即随着变形温度的降低、应变速率的升高而减小。B95оч铝合金热变形的流变应力行为可以用包含Arrhenius项的Zener-Hollomon参数来描述,其变形激活能为124.09 kJ·mol-1。     

5A30铝合金板高温拉伸本构关系研究

采用拉伸试样在Gleeble-1500材料热模拟试验机上对5A30铝合金进行高温拉伸实验,研究了该合金在变形温度为300～500℃,应变速率在0.01～10 s-1的高温流变变形行为。结果表明:变形温度和应变速率对该合金流变应力的大小有显著影响。流变应力随变形温度的升高而降低,随着应变速率的增加而升高。5A30铝合金的高温流变行为可用Zener-Hollomon参数描述,从流变应力、应变速率和变形温度的相关性,得出了该铝合金板材高温变形的材料常数和本构方程。计算出5A30铝合金板的变形激活能为Q=201.1 kJ.mol-1,材料常数为A=7.44×1013 s-1,n=4.3135,α=0.02 mm2.N-1;计算得到了5A30铝合金Arrhenius方程;利用双曲正弦模型,得到高温拉伸峰值应力和Z参数的解析式。     

7085铝合金热变形的流变应力行为和显微组织

采用Gleeble-1500热模拟机进行热压缩实验,研究7085铝合金在变形温度为350~470℃、应变速率为0.001~1 s?1条件下的流变应力变化规律和变形后的显微组织。研究表明:7085铝合金的流变应力随应变速率增大而增大,随变形温度升高而减小。该合金热压缩变形的流变应力行为可用双曲正弦形式的本构方程描述为ε=A[sinh(ασ)]nexp(?Q/RT),也可用Zener-Hollomon参数来描述,其参数A、α、n以及热变形激活能Q分别为2.722 54×1011s?1、0.016 03 MPa?1、6.259以及176.58 kJ/mol。随着温度升高和应变速率降低,合金的主要软化机制由动态回复逐渐转变为动态再结晶。     

Al-4．8Cu-0．5Mg-0．3Ag-0．15Zr合金的热变形研究

采用Gleeble-1500热模拟机进行恒温和恒速压缩变形实验,变形温度范围为400～460 ℃,应变速率为0.001～0.1 s-1.研究了Al-Cu-Mg-Ag-Zr合金在高温塑性变形过程中流变应力的变化规律,确定了合金的变形激活能Q和应力指数n.结果表明:流变速率和变形温度对合金流变应力的大小有显著影响,流变应力随变形温度的升高而降低,随应变速率的提高而增大.可用包含Arrhenius项的Zener-Hollomon参数描述该合金高温塑性变形时的流变行为.     

Chinalco Signed Framework Agreement for Strategic Cooperation with Harbin Municipal Government

正Last month,Chinalco signed framework agreement for strategic cooperation with Harbin Municipal Government in Harbin Xiong Weiping,Chairman of Chinalco,said that based on the strategic deployment to build world top-class mining company with the highest growth potential,Chinalco was now concentrating all efforts on making strategic transition and structural adjustment,strategic cooperation with the local governments where     

Jiangxi Promotes Jiangxi Copper Corporation To Become The World's Most Competitive Mining Company

<正>According to the latest info from Jiangxi Province State-owned Assets Supervision and Administration Commission,Jiangxi Copper Corporation was approved to become the first pilot enterprise for deepening reform.Contents of the pilot work is"Three Self"(self expansion,self decision-making,self     

Journal of Rare Earths Contents List of Vol.32(2014)

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Contributions to Baosteel Technical Research wanted

正Baosteel Technical Research,a quarterly journal,which is issued domestically and abroad,is run and sponsored by Baosteel Group Corporation.Baosteel Technical Research mainly reports the achievements in technological innovation,academic research,new product development and industrial equipment improvement by Baosteel.It will continue to follow up on hot topics and serve the company’s technological development and progress.Its readers include experts in     

Ministry of Industry and Information Technology: No Short Term Solution For Our Country’s Excess Nonferrous Metal Smelting Capacity

【正】According to the Ministry of Industry and Information Technology,the Ministry has released the 2013 Operation Report on China’s Industrial Communication Indu...     

Chinalco Signed Framework Agreement for Strategic Cooperation with Gansu Province

正Recently,Chinalco and Gansu Provincial People’s Government signed"Framework Agreement for Strategic Cooperation on Reform,Restructuring and Transition Development of Chinalco’s Electrolytic Aluminum Enterprises in Gansu",signifying that the strategic cooperation between Chinalco and Gansu Province had made new substantive progress.     

Unavoidable Economic Cycle:30% Of Nonferrous Metal Companies Were Involved In Restructuring

正Owing to continual downturn in real estate and bulk commodity markets,a number of traditional industries in China suffered unfavorable impact in performance.With the progressive disclosure of third quarter report,the no-pleasant-surprise performance of     

Baotou Rare Earth Became the World's Biggest High Performance Magnetic Material Base

正The High Performance Magnetic Material Phase II Project,an industry upgrading project implemented by Inner Mongolia Baotou IronSteel Rare Earth(Group)Hi-tech Co.,Ltd,recently basically finished equipment commissioning,signifying that the enterprise had developed the production capacity of15000 t/a Nd-Fe-B strip casting alloy and 5000t/a Nd-Fe-B magnet,thus becoming the world’s     

Introducing Two Central Enterprises to Integrate Rare Earth Industry,Shandong Rare Earth Group Breaks Surface

正With the signing of"Letter of intention for Propelling Integration of Shandong Rare Earth Enterprises"between Shandong Province Commission Of Economy and Informatization,China IronSteel Research Institute Group("China Steel Institute"),and China Rare MetalsRare Earth Co.,Ltd("China Rare Earth"),the"Shandong Rare Earth Group"jointly set up by the 3 units thus broke surface.On August 9,reporters of the China Economic Herald learned from Shandong Province     

Aluminium Production by Province or City in 2014

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