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℃)。     

Ti-25Al-14Nb-2Mo-1Fe合金热压缩变形流变应力行为与微观组织演变的研究

在Gleeble-3500热模拟试验机上对Ti-25Al-14Nb-2Mo-1Fe合金进行了等温恒应变速率压缩试验,研究了在变形温度为950~1 100℃,应变速率为0.001~1 s-1,最大变形程度为50%的条件下合金的热压缩变形流变应力行为与微观组织演变。结果表明:Ti-25Al-14Nb-2Mo-1Fe合金的流变应力对变形温度和应变速率均较为敏感,其流变应力曲线具有应力峰值、流变软化和稳态流变的特征。在变形温度为950℃,应变速率为0.001~0.1 s-1的条件下,Ti-25Al-14Nb-2Mo-1Fe合金的热变形特性为片层组织球化,其热变形机制可用晶界分离球化模型进行解释说明;在变形温度为1 000~1 100℃,应变速率为1 s-1的条件下,材料只发生了动态回复现象;在变形温度为1 050~1 100℃,应变速率为0.001~0.1 s-1的条件下,材料发生了动态再结晶现象。     

Monel K-500合金高温流变特性及其本构方程

采用Gleeble 3800热模拟实验机研究了Monel K-500合金在变形温度为850~1 100℃,应变速率为0.01~10s-1时的高温流变行为,测定了合金在不同条件下的流变应力曲线。结果表明,最大压缩变形量对合金的流变行为影响不大;变形温度相同时,合金在应变速率为0.1s-1时取得最大峰值应变;根据Arrhenius模型得到了合金的热变形本构方程。     

7N01铝合金热压缩流变行为研究

采用Gleeble-1500D热模拟机进行热压缩变性试验,研究7N01铝合金在变形温度为340 ～460℃、应变速率为0.01～ 10.00 s-1条件下的流变应力行为.结果表明:变形温度和应变速率对合金流变应力有显著影响,流变应力随变形温度的升高而降低,随应变速率的增加而升高;合金在低应变速率(0.01,0.10,1.00s-1)时主要为动态回复软化机制,而在高应变速率(10.00 s-1)时出现动态再结晶软化;7N01铝合金的高温流变行为可用Zener-Hollomon参数描述.     

6005A与6082铝合金热变形流变行为

利用Gleeble-1500热模拟试验机对6005A和6082铝合金进行高温等温压缩试验,研究了在变形温度为450~550℃和应变速率为0.005~10 s-1条件下两种铝合金的热变形流变行为.6005A铝合金在低应变速率条件下,不同变形温度时的流变曲线均呈现波浪形特征,随着应变速率的增加,硬化和软化接近平衡,表现为稳态流变特征;在高应变速率条件下,硬化过程占据主导地位,回复和硬化过程的竞争使流变曲线呈现波浪形上升的趋势.6082铝合金在低应变速率情况下,不同变形温度时的流变曲线未出现周期性波动;在中等应变速率条件下也表现为稳态流变特征;在高应变速率条件下出现波浪形特征.两种铝合金均为正应变速率敏感材料,其热变形是受热激活控制.最后给出了铝合金热变形条件下流变应力、应变速率和变形温度三者之间的关系式.      

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。     

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.     

Cu-Cr-Zr合金的热变形行为

采用Gleeble-3500热模拟实验机对Cu-Cr-Zr合金进行了压缩变形实验,分析了在变形温度为25~700℃、应变速率为0.0001~0.1000s-1的条件下流变应力的变化规律,利用扫描电镜及透射电镜分析合金在热压缩过程中的组织演变及动态再结晶机制。结果表明:Cu-Cr-Zr合金在热变形过程中发生了动态再结晶,且变形温度和应变速率均对流变应力有显著的影响,流变应力随着变形温度的升高而降低,随着应变速率的增加而升高,说明该合金属于正应变速率敏感材料;当变形温度为400~500℃时,低应变速率(0.0001~0.0010 s-1)的真应力-真应变曲线呈现动态再结晶曲线特征,高应变速率(0.01~0.10 s-1)的真应力-真应变曲线呈现动态回复特征;在真应力-真应变曲线的基础上,采用双曲正弦模型能较好地描述Cu-Cr-Zr合金高温变形时的流变行为,建立了完整描述合金热变形过程中流变应力与应变速率和变形温度关系的本构方程,确定了合金的变形激活能为311.43 kJ·mol-1。     

ODS-310合金的热变形行为及热加工图

采用Gleeble-1500D热模拟试验机研究机械合金化制备的ODS-310合金在变形温度为1 050~1 150℃、应变速率为0.001~1 s-1条件下的高温变形行为,测定其真应力-应变曲线,分析其流变应力与应变速率及变形温度三者之间的关系,并采用Zener-Hollomon参数法建立ODS-310合金的高温变形本构方程,基于动态材料模型,构造ODS-310合金的热加工图。结果表明:ODS-310合金的流变应力随变形温度降低或应变速率提高而增大;该合金热变形过程中的流变行为可用双曲线正弦模型来描述,在实验条件下的平均变形激活能为828.384 kJ/mol;真应变为0.4的热加工图表明,ODS-310合金在高温变形时存在2个加工失稳区,即变形温度为1 050~1 070℃、变形速率为0.01~1s-1的区域,和变形温度为1 130~1 150℃、变形速率为0.1~1 s-1的区域;ODS-310合金的最佳变形温度和应变速率分别为1 150℃和0.001 s-1。     

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.     

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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