CuNi15Sn9合金铜镍合金真空冶金工艺及防止偏析的方法
通过对铸锭界面的金相及扫面电镜的分析发现CuNi15Sn8（X0。01）合金的铸锭的树枝晶占金相组织的绝大部分，其中，贫Sn富Ni的Cu-Ni固溶体呈明显的白色，偏析严重的富Sn相呈白亮色，合金的基体呈灰色。研究发现加入不同的微量元素后合金的金相组织与不加产生在微观上具有差异。87358
研究表明，再加入0。1%的微量元素后，除Nb，Si以外，从金相上分析发现微量元素的加入对富Sn相的偏析的抑制作用有限。后进行扫描电镜分析发现虽然加入微量元素后，虽然富Sn相中的含Sn量没有明显的降低，但是，富Sn相的数量明显降低，最终的ICPA对外围偏析严重的地方做的研究证明了加入微量元素对Sn的偏析有积极作用。本文在最终还进行了热力学和动力学进行验证所得结论，对渣系和坩埚与合金之间的作用解释了实验中的微量元素的烧损原因。
毕业论文 关键词：CuNi15Sn8合金；真空冶金；预防偏析
Abstract Through adding 0。1% of Cr,Mn,Nb,Si,Ti,Zr into each of the CuNi15Sn9 power and smelting them twice。We finally get seven ingots to study about how does microeleme affect the segregation of Sn in CuNi15Sn8 ally。This study explain it the by doing metallographic analysis , scanning electron microscope analysis and plasma spectrum analysis。Except doing experimental study, this study also explain the conclusion by applying dynamics and thermodynamic theory to the date that get in the study。The thesis also study how vacuum metallurgy works。
The CuNi15Sn8 alloy microstructure of ingots show obvious dendrite sharp,the white tissue is Cu- Ni solid solution which is poor Sn rich Ni and white light objects of Sn rich phase is segregation seriously and between the white and black matrix。The microstructure of CuNi15Sn8 alloy is different from those alloys adding microeleme。
After doing all the experiments,the thesis got the following conclusions:
Except Nb and Si,other elements have limited affect on segregation of Sn in CuNi15Sn8 ally in metallographic。and after doing SEM,the thesis find that microelemes have strong effect in reducing the among of the Sn rich phase。And,the study of the outer-ring,which area segregation seriously,shows that the adding of 0。1% Cr,Mn,Nb,Si,Ti,Zr have positive affect on it。finally,the thesis also study about how does slag and crucible affect the result of the study。
Keyword: CuNi15Sn8 ally ；vacuum metallurgy ；prevent segregation
目录
第一章 绪论 1
1。1 引言 1
1。2 铜镍锡合金的研究现状与性能 1
1。3合金元素对白铜的影响 2
1。3。1锌 2
1。3。2 铁 2
1。3。3 铝 2
1。3。4锰 2
1。3。5锡 3
1。3。6硅 3
1。3。7合金元素对Cu-15Ni-8Sn合金的力学和电学性能的影响 3
1。4合金的熔炼 3
1。4。1铜合金的熔炼的作用和目的 3
1。4。2 铜合金熔炼过程中的主要化学反应 4
1。4。3 铜合金熔炼过程的气体来源 5
1。4。4 防止熔体吸气的方法 6
1。4。5 合金熔炼过程中的脱氧方法 6