共查询到20条相似文献,搜索用时 46 毫秒
1.
采用快速凝固技术制备了厚度30~35μm 的 Mo-Th-B 合金箔和厚度50~55μm 的薄带。快速凝固细化了晶粒,扩大了钍和硼在钼中的固溶度,显示了强的时效硬化效应,使合金具有高硬度和强度,尤以高钍和高硼含量合金为甚。时效强化相为 ThB_4(四方晶格)和 Mo_2B(体心四方晶格)。因钍、硼从亚稳固溶体中脱溶程度不同,不同 Mo-Th-B 合金达到时效峰的时间亦不同。本文和我们早先的研究结果表明,采用快速凝固技术可以开发新的高强度钼合金。 相似文献
2.
通过单向凝固,成功地制了规则纤维排列的Fe-C-Cr共晶复合材料。研究发凝固速度对材料组织和性能的影响,研究表明,随着凝固速度(R)的增加,纤维间距减小,规整性变差,而材料的抗拉强度呈抛物变化,当R=50mm/h时,可达2300MPa。提出了该共晶合金在单向凝固过程中碳化物增强纤维的生长模型。 相似文献
3.
本研究通过对HQ—70钢连续冷却转变(CCT)图的测定、组织状态分析、系列温度下切口试样冲击性能试验以及断裂特性考察,阐明了该钢冷脆机制及显微组织控制因素。结果指出:与回火索氏体状态相比,粒状贝氏体的出现使该钢的冷脆倾向性加剧,仅约20%(体积)的粒贝组织就使塑-脆转折临界温度T_(ce)大幅度提高,粒贝含量继续增加时T_(ce)的升值趋于饱和。粒贝组织致脆机制系由低温下的解理断裂特性决定。最后确定了改善冷脆抗力、避免粒贝形成所应保证的最低冷却速度ν_e=40℃/s。 相似文献
4.
5.
6.
采用快速凝固技术制备了Cu-Fe合金。使用VHX-600超景深显微镜对Cu-Fe合金快速凝固组织进行观察,且与其普通凝固条件下的微观组织作对比,研究了快速凝固对铜铁合金的凝固过程和微观组织的影响。结果表明:快速凝固可以产生很大的过冷度,Cu-Fe合金与Cu-Co合金一样在快速凝固过程中发生液相分解。 相似文献
7.
8.
9.
以快速凝固A1—4Ti—2V—3La合金作为研究对象,研究合金的显微结构、热稳定性和力学性能。提出为改善Al-Ti—RE基热强合金的显微组织和性能的合金设计原则,应进一步多元化,其中Ni、Cr元素比较理想,它们与Ti的物理性质相近,在α—Al中有较高的极限固溶度和较低的平衡固溶度,在高温有较低的扩散速率,具有较高的表面张力,并能改善熔体的微观不均匀性。 相似文献
10.
以磁场对合金凝固组织的影响为基础,综述了近年来交变磁场和稳恒磁场在定向凝固过程中的应用和发展,总结了外磁场对定向凝固过程中合金微观组织的作用机制,并展望了今后的研究方向。 相似文献
11.
实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。 相似文献
12.
13.
14.
<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 相似文献
15.
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, 相似文献
16.
《China Nonferrous Metals Monthly》2014,(10)
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 相似文献
17.
《China Nonferrous Metals Monthly》2014,(10)
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 相似文献
18.
《China Nonferrous Metals Monthly》2014,(10)
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, 相似文献
19.
《China Nonferrous Metals Monthly》2014,(12)
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. 相似文献
20.
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. 相似文献