铸造高铌TiAl合金双态组织转变过程

通过对Ti-46Al-8Nb-2Mn-0.2B合金的铸态组织和经过α+γ双相区热处理后的组织进行光学和扫描电镜进行观察,发现原始铸态组织的γ相偏析处不是片层的晶界,而是片层穿越的区域.由于γ相偏析区域的Al含量比片层基体高,因此阻碍了后续回火过程中该偏析部位片层的分解.通过先得到近γ组织,然后经过α+γ双相区保温,最终得到晶粒为40μm的双态组织;但组织中有少量的β相没有得到消除.     

NiCoCrAlY合金的铸态显微组织研究

采用真空感应熔炼的方法制备了NiCoCrAlY合金锭,并对合金的铸态显微组织进行了研究。结果表明:NiCoCrAl Y铸态合金主要由4个相组成,分别为γ相、γ'相、Y富集相及共晶组织β+γ'。其中Y富集相为Ni3.55Co0.5Cr0.2Al0.75Y,以网状形式偏聚于γ相周围;共晶组织中β相为(Ni,Co)Al,γ'为(Ni,Co)3Al,且γ'呈圆棒状镶嵌在β相中。     

单晶高温合金DD6不同状态下的显微组织和力学性能

研究了低成本的第二代单晶高温合金DD6在铸态、固溶处理状态和完全热处理状态的显微组织、拉伸性能和持久性能.结果表明在铸态、固溶处理和完全热处理三种状态中,完全热处理状态下DD6合金拉伸强度和持久寿命最高,分别为铸态的1.1倍和2.5～3倍;采用适当的热处理工艺可提高DD6合金中γ'相的数量,改善γ'相的尺寸和分布,显著提高合金的综合力学性能.     

热处理消除铸态TiAl基合金组织中的β(B2)相

利用光学显微镜和扫描电镜,研究热处理对铸态Ti-43Al-4Nb-1.4W-0.6B-0.1Y合金及其在1 200℃锻造后的组织中β(B2)相偏析的影响。结果表明:在α+γ两相区保温适当时间,可减少铸态合金组织中的β(B2)相偏析,经1 250℃/6 h+AC(air cooling)热处理后,晶界处和片层内的β(B2)相偏析明显减少,但不能消除β(B2)相;经过热变形后,β(B2)相发生变形甚至被破碎,有利于β(B2)相在随后的热处理中消除;热处理后,合金中β(B2)相的含量与变形中的动态再结晶密切相关,高应变速率下β(B2)相动态再结晶不完全,在随后的热处理过程中,由于变形储能的作用更易消除β(B2)相。     

热处理对定向凝固CMSX-6合金组织及拉伸性能的影响

采用高速凝固法制备了CMSX-6镍基高温合金定向凝固试样。研究了热处理前后不同部位的显微组织和拉伸性能。结果表明,铸态试样先凝固部分比后凝固部分的枝晶组织更为细密,一次枝晶间距较小,共晶组织含量较少,而抗拉强度高,延伸率较小。热处理后初生相充分固溶形成了成分均一的组织,γ′相得到了明显的细化与均匀化,γ/γ′共晶也发生了溶解并存在固溶微孔。热处理略微提高合金的抗拉强度,但明显提高了合金的延伸率。试样断裂为脆性断裂,铸态为正断型断裂,热处理态为切断型断裂。     

钛铝合金铸件的组织均匀细化方法

本发明属于金属热处理技术领域。特别适用于钛铝合金铸件的层片状原始铸态组织的均匀化和细化。该方法是将钛铝合金铸件首先经热等静压在α相区高温处理,然后进行循环热处理和共析温度等温处理,最后是进行临界温度处理。本发明方法与现有技术相比较,可以使铸造钛铝合金的全层片状组织得到明显均匀细化,和接近变     

高铌TiAl基合金热变形组织的均匀化

研究了热加工和热处理对大尺寸高铌TiAl基合金组织均匀化的影响.结果表明,两次包套锻造能够有效地破碎大尺寸高铌TiAl基合金铸态组织.锻造过程中,铸态组织发生较大程度的动态再结晶,合金锻后组织经过热处理未出现残留的粗大的片层组织.合金在凝固中由于偏析形成的高温β相通过热加工和随后的热处理得到了有效的消除,热处理后所获的双态组织均匀且细小.     

热处理温度对内燃机用Ti-42.5Al-4Nb-1Mo-0.2B合金组织的影响

研究了热处理温度对内燃机用Ti-42.5Al-4Nb-1Mo-0.2B合金微观组织的影响。结果表明,合金在铸态下为近片层组织,主要由较细小的片层团以及片层团周围的B2相和γ相组成。合金在1 200℃和1 250℃下的淬火组织相近;随着淬火温度升高至1 300℃,合金淬火组织内γ相消失,B2晶粒中含有部分长棒形的细小α_2晶粒。合金经1 200℃热处理并冷却至室温后组织中包含α_2/γ片层团、B2相以及γ相;当热处理温度升至1 250℃时,α晶粒以及α_2/γ片层团的数量均开始增加,且两者尺寸也逐渐增大;当热处理温度升至1 300℃时,合金内生成了近片层状的细小α+β组织。     

热控制制度强化再生A356铝合金性能研究

文章考察了废铝制品制备再生A356铝合金过程中精炼除杂脱气、冷却制度及热处理条件对再生铝合金组织结构及力学性能的影响,研选了提升再生A356铝合金力学性能的关键工艺参数,结果表明：通过投加自制Ti-C₂Cl₆精炼剂,再生铝合金浇注后立即室温水淬骤冷,以及固溶+时效的热处理等步骤,可实现脱气除杂、晶粒细化和抑制β-Fe相生成目的,所得铸态再生A356铝合金抗拉强度由201 MPa大幅度提升至277 MPa,将有助于推动汽车用再生铝技术的高质量发展。     

热处理对一种Ni3Al基单晶合金组织的影响

利用光学显微镜和扫描电镜对Ni3Al基单晶合金IC21的铸态组织和不同热处理制度后的组织进行了观察,研究了固溶温度和时效温度对合金热处理组织的影响.研究结果表明,IC21单晶合金的铸态组织由γ’相、γ相以及枝晶间的白色块状析出相组成,枝晶干上γ’相尺寸比枝晶间的γ’相尺寸大.IC21单晶合金的初熔温度约为1345℃,热处理窗口约为65℃.枝晶间γ’相的溶解温度低于枝晶干γ’相的溶解温度.固溶温度越高,时效处理后γ’相的尺寸越均匀.一级时效处理温度对γ’相的尺寸、形态和数量有明显影响.随着一级时效温度的增加,γ’相的体积分数和尺寸增加,形状由类球状向立方状再向长条状转变.1320 ℃/10 h/aac+ 1060℃/2 h/ac +870℃/32 h/ac热处理后可使合金获得γ’相尺寸和分布均匀且立方度高的优良组织.     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.