FGH95粉末冶金高温合金的超塑性

FGH95粉末冶金高温合金,是制造航空发动机涡轮盘的材料。本文研究了 FGH95的超塑性行为,介绍了获得超塑性材料的工艺方法。结果表明,当晶粒度<10μm,温度为950～1100℃,应变速率为10~(-1)～10~(-2)/min 时,该合金具有良好的超塑性,最大延伸率可达726%。     

超塑性合金

摘自《日經力》5(1989),1,92～94. 为了显示超塑性现象一般要求合金具备三个条件:(1)形成粒径约数微米的等轴晶粒组织,并且在变形过程中晶粒组织必须不因热作用而粗化;(2)变形速度在10~(-3)～10~(-5)/s范围以内,超出此范围就会使得延伸率减小;(3)超塑性加工温度高于其熔点绝对温度的1/2,即处于其超塑性温度范围以内,超出此范围则不利于超塑性变形。另外还有在合金加热或冷却过程中相变时显示超塑性的“相变超塑性”。超塑性成型特別有利于在难加工材料的复杂形状成型加工。铝合金、钛合金和镍合金的超塑性加工件,已     

细晶Ti-6Al-4V合金的超塑性变形行为与组织演变

对不同温度下退火处理后的细晶TC4合金板材进行超塑性拉伸变形,研究该合金在750~850℃,应变速率为3×10-4~1×10-3 s-1条件下的超塑性拉伸变形行为,分析晶粒尺寸、变形温度和β相含量对合金性能的影响。结果表明:退火后的(α+β)型细晶Ti-6Al-4V合金表现出良好的超塑性,并且晶粒越细,最佳超塑性变形温度越低。晶粒直径为2.5μm、β相含量(体积分数)为9.6%的TC4合金在温度为800℃、应变速率为1×10-3 s-1的变形条件下,伸长率最大,达到862%。不同晶粒度合金的应变速率敏感系数m均随变形温度升高先上升后下降,最高达0.61。β晶粒处于α晶粒三叉晶界处,升温或拉伸变形时聚集并沿α晶界长大,形成细长的β晶粒并逐渐变粗大,因此在900℃以上高温下合金的超塑性变形能力降低。     

Zn-0.66％Cu-0.38％Mn合金的超塑性

本文对一种在固溶体基体上分布有弥散化合物微粒的锌基合金进行了超塑性研究。急冷凝固的Zn-0.66％Cu-0.38％Mn合金经晶粒微细化处理后获得了晶粒平均直径小于10μm的微细晶粒组织。在250～300℃和3×10~(-4)～4×10~(-3)s~(-1)的初始应变速率拉伸条件下,此合金呈现出典型的超塑变彤力学特征。Ⅱ区内的m值约为0.49,延伸率约为300％。250℃时应变速率、流变应力σ及平均晶粒直径d之间符合ocσ~2/d~2关系。在250～300℃温度范围和恒定应力条件下测得此合金的超塑变形激活能为54.2±5.6kJ/mol,与纯锌的晶界自扩散激活能很接近,说明此合金的超塑变形是由晶界自扩散所控制的。     

郑州轻研成功开发航空航天用铝锂合金超塑性板材

正日前,郑州轻研合金科技有限公司开发的航空航天用铝锂合金超塑性板材成功完成交付,板材宽幅1.2 m、长度4 m、厚度1.5～3 mm。与普通铝锂合金板材相比,该合金板具有晶粒细小、强度高、塑性好的优点,工业化批量生产的板材高温伸长率达到500%,可在高温条件下超塑性制造成形。     

LY12工业铝合金的超塑性预处理及超塑性拉伸变形研究

本文对工业铝合金LY12的超塑性预处理工艺及超塑性拉伸变形进行了试验与研究分析。结果表明:经过一定的锻造热变形与稳定化处理后,可以得到较细小均匀稳定的晶粒组织,具有超塑性性能,在430℃,ε=1.67×10~(-3)S~(-1)时,延伸率δ为255％,m值为0.3～0.36,它提供了利用超塑性成形的可能性。     

TA32钛合金板材的超塑性能研究

研究了真空环境中TA32钛合金板材在温度950℃、应变速率5.32×10^-4~2.08×10^-2 s^-1条件下的超塑性变形行为。结果表明,在不同应变速率条件下,合金的流变应力曲线特征和显微组织演变显著不同。在应变速率较低(5.32×10^-4~3.33×10^-3 s^-1)条件下,拉伸真应力-真应变曲线呈传统超塑变形的稳态流动特征,变形后的合金中初生α相晶粒尺寸较大;在高应变速率(8.31×10^-3 s^-1~2.08×10^-2 s^-1)条件下,拉伸真应力-真应变曲线中流变应力增大到峰值后快速单调递减直至试样断裂,合金变形过程中初生α相发生动态再结晶,晶粒尺寸较低应变速率条件下显著细化。950℃时,TA32钛合金板材均具有超塑性变形能力,超塑性延伸率在145%~519%之间;当应变速率为5.32×10^-4 s^-1时,具有最佳的超塑性,拉伸延伸率可达519%。断裂区形貌分析发现,TA32钛合金板材的超塑性断裂模式为空洞聚集-连接-长大型断裂。     

Cu、Mg合金元素对Zn—Al22合金组织和性能的影响

Zn—Al22超塑性合金属于细晶超塑性类合金,即合金材料在成型前,应具有等轴两相微细晶粒(一般在0.5～5μm);其成型温度的下限为0.5Tm(Tm为材料熔点);并且应变速率要在10~(-1)～10~(-4)/sec之间。 Zn—Al22合金用于生产是在六十年代     

热挤压粉末IN100合金的超塑性

本工作采用氩气雾化INl00合金粉,经真空脱气,装入不锈钢套,封焊后,进行热挤压。挤压棒材具有良好的超塑性,在温度为1040℃应变速率为10~(-2)～10~(-3)/min时,拉伸试样的延伸率可达824～1090％,流动应力仅为1.O～1.5kgf/mm~2。本文研究了挤压工艺参数对合金超塑性和机械性能的影响,探索了最佳超塑性的温度范围,研究了超塑性合金的组织特点以及经热处理后的组织变化。试验结果说明热挤压粉末IN100合金的室温和7000℃的抗张性能以及持久性能均优于铸造IN100合金。     

ZnAl_(5-0.03)合金超塑性的研究(Ⅳ)——超塑性变形过程中显微组织的变化

ZnAl_(5-0.03)合金超塑性变形过程中晶粒的热长大是次要的,而变形量能有效地促进晶粒长大,在大变形量的条件下还伴随着呈现孔洞。提高应变速率使晶粒细化,组织微粒化,在高应变速率下呈现孔洞,继续提高应变速率会使孔洞发展。本文还讨论了变形过程中显微组织变化规律与超塑性力学行为间的关系。     

Acceleration of Electricity Reform Brings Benefit to Big Electricity Users,Aluminum Manufacturers Can Save Costs Up to Several Hundred Million

<正>Recently the National Commission of Development and Reform again assembled experts to solicit opinions,and discussed new electricity reform program.According to information disclosed by experts attending the meeting,in the future electricity reform will undergo top-down design,possibly a     

Qinghai's Aluminum Processing Capacity to Rise at the End of the Year

正Since the release of Implementation Opinions on Carrying out‘Guiding Opinions of the State Council on Resolving Serious Production Overcapacity Conflicts’,according to the actual situation of industry,Qinghai has focused on electrolytic aluminum,cement,ironsteel(including iron alloy and silicon carbide),     

Recent Trends in China's Copper Scrap Market-Part Ⅱ

<正>2.Tianjin Scrap Metal Market In Tianjin,we mainly visited Jinghai Ziy Town scrap market and Binhai New Area’some copper scrap enterprises and enterprise using copper scrap.In Ziya we felt the coppe scrap market was particularly deserted,mos copper scrap enterprises in the town wer closed,industry insiders said in 2012 the plac here was bustling with activity.According to     

Shanghai Clearing House to Roll out Renminbi-denominated Copper Clearing Operations in Free Trade Zone

正Clearing House Financial Markets Co.,Ltd.(Shanghai Clearing House)General Manager Xie Zhong told the media recently at the briefing of the international symposium of"Reform Deepening and Mechanism Innovation of the Post-crisis Kerb Market",Shanghai Clearing House will explore the feasibility of carrying out bond business in     

Development and Application of New Materials for Copper Processing in China

正After over 60 years of developmnt,a system for RD and production of copper processing materials has already taken shape in China.After the reform and opening-up,the application of copper processing materials has gradually expanded from the military industry to civil field.The annual output of copper     

China’s Mineral Exploration Market Downturn Causes Decline of Investment in Bauxite

<正>According to a survey report conducted recently by China Geological Survey Development Research Center,in the first half of 2014,China’s mineral exploration market continued to decline,with the investment in exploration of non-fuel minerals dropping by13.7%and drilling workload dropping by21.7%.According to statistical analysis of the Center,     

Chinalco and China National Administration of Coal Geology Jointly Built Guangxi Rare Earth Industrial Base

正On June 3,Chinalco and China National Administration of Coal Geology signed cooperation agreement for strategic cooperationcooperation agreement between Chinalco Guangxi Nonferrous Rare Earth Development Company and Xuzhou Jin Shi Pengyuan Rare Earth Material Factory.According to the agreement,both sides would jointly support Chinalco Guangxi Nonferrous Rare Earth Development Company and Xuzhou Jin Shi Pengyuan Rare Earth Material Factory to carry out comprehensive cooperation covering rare     

Aluminium Production by Province or City in 2014

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Fabricated Copper Production by Province or City in 2014

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Zinc Production by Province in 2014

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