本文選題：超細(xì)粉末　切入點(diǎn)：銀包銅　出處：《北京有色金屬研究總院》2017年碩士論文　論文類型：學(xué)位論文

【摘要】：超細(xì)銀包銅粉可以充分發(fā)揮銀的高導(dǎo)電性和抗氧化性能,改善超細(xì)銅粉的物化性能,降低純銀粉的應(yīng)用成本。因此,超細(xì)銀包銅粉被越來(lái)越多的應(yīng)用在導(dǎo)電涂料、導(dǎo)電膠等產(chǎn)品中。但是,超細(xì)銀包銅粉在應(yīng)用中仍然存在著導(dǎo)電性能不夠,抗氧化性能差的缺點(diǎn),而且國(guó)內(nèi)產(chǎn)品與國(guó)外一些企業(yè)的產(chǎn)品相比存在著一些不足。所以,本課題的目的是通過(guò)對(duì)銀包銅粉制備工藝的研究,提高粉末的性能,填補(bǔ)市場(chǎng)中高性能超細(xì)銀包銅粉的不足,替代國(guó)外相關(guān)產(chǎn)品。本課題實(shí)施的意義在于,對(duì)超細(xì)銅粉進(jìn)行銀包覆以后,不但可以改善銅粉的抗氧化性、導(dǎo)電性,拓展超細(xì)電解銅粉的應(yīng)用領(lǐng)域,同時(shí)可以替代銀粉,在滿足電磁屏蔽、導(dǎo)電填料、導(dǎo)電膠等領(lǐng)域的需求方面具有重要價(jià)值。本課題以超細(xì)電解銅粉為原料,通過(guò)分析對(duì)比直接置換、化學(xué)還原法的實(shí)驗(yàn)原理及實(shí)驗(yàn)結(jié)果,確定了以復(fù)合法制備超細(xì)銀包銅粉末的工藝。通過(guò)優(yōu)化實(shí)驗(yàn)研究了超細(xì)銀包銅粉制備過(guò)程中分散劑、還原劑對(duì)粉末性能的影響,并確定了絡(luò)合分散劑和還原劑種類及用量,還研究了體系pH值和銀氨添加速率等實(shí)驗(yàn)參數(shù)對(duì)制備工藝的影響。通過(guò)掃描電子顯微鏡、能譜儀、X射線衍射儀、氧含量測(cè)試儀、激光粒度儀、熱重分析儀等設(shè)備對(duì)超細(xì)銀包銅粉末的結(jié)構(gòu)和性能進(jìn)行了分析,同時(shí)與原料銅粉和超細(xì)銀包銅粉產(chǎn)品在性能上進(jìn)行了對(duì)比研究。最后,對(duì)超細(xì)銀包銅粉在導(dǎo)電膠中的應(yīng)用進(jìn)行了研究,并且比較了使用不同導(dǎo)電粉作為導(dǎo)電填料的導(dǎo)電膠的性能和結(jié)構(gòu)。得出了以下結(jié)論:(1)本實(shí)驗(yàn)選擇超細(xì)電解銅粉作為原料進(jìn)行鍍銀。通過(guò)對(duì)比不同化學(xué)鍍方法,本課題確定了一種置換預(yù)鍍銀和化學(xué)還原相結(jié)合的復(fù)合法制備超細(xì)銀包銅粉。(2)通過(guò)對(duì)超細(xì)銀包銅粉制備過(guò)程中使用的化學(xué)試劑的實(shí)驗(yàn)分析,本實(shí)驗(yàn)確定了粉末制備工藝中的主要試劑為:一定量的EDTA-2Na作為絡(luò)合分散劑,酒石酸鉀作為還原劑更合適;通過(guò)對(duì)工藝中各參數(shù)的調(diào)整,確定了制備超細(xì)銀包銅粉過(guò)程中的參數(shù):體系溫度為30℃、pH為9～10、鍍液濃度為0.4mol/L、鍍液添加速率為8mL/min。(3)對(duì)粉末的結(jié)構(gòu)分析表明,粉末顆粒分散均勻,表面光滑;制備的超細(xì)銀包銅粉有完整的包覆結(jié)構(gòu),且包覆結(jié)構(gòu)均勻致密;粉末的銀包覆層能夠達(dá)到一定厚度。實(shí)驗(yàn)表明,制備粉末比市場(chǎng)中某產(chǎn)品氧含量和電阻率更低;包覆后的粉末與原料銅粉相比抗氧化性能得到較大提高;熱重分析結(jié)果中顯示,制備的超細(xì)銀包銅粉末的抗氧化性能優(yōu)于原料銅粉和某產(chǎn)品銀包銅粉。(4)將不同的導(dǎo)電粉制備成的導(dǎo)電膠,對(duì)導(dǎo)電膠的結(jié)構(gòu)和性能進(jìn)行分析可得,制備的超細(xì)銀包銅粉末制備成導(dǎo)電膠后有較好的導(dǎo)電性能,已經(jīng)達(dá)到了市場(chǎng)中某片狀銀包銅粉的性能;通過(guò)SEM圖片可以看出,制備的粉末能夠在導(dǎo)電膠中形成連接,起到導(dǎo)電的作用。
[Abstract]:Ultrafine silver coated copper powder can give full play to the high electrical conductivity and oxidation resistance of silver, improve the physical and chemical properties of ultrafine copper powder, and reduce the application cost of pure silver powder. However, in the application of ultrafine silver coated copper powder, there are still some shortcomings such as insufficient electrical conductivity and poor oxidation resistance, and there are some shortcomings in domestic products compared with those of some foreign enterprises. The purpose of this project is to improve the properties of silver coated copper powder by studying the preparation process of silver coated copper powder, to fill the shortage of high performance superfine silver coated copper powder in the market, and to replace foreign related products. After silver coating of ultrafine copper powder, not only can the oxidation resistance and electrical conductivity of copper powder be improved, but also the application field of ultrafine electrolytic copper powder can be expanded. At the same time, it can replace silver powder and meet the requirements of electromagnetic shielding and conductive filler. The demand of conductive adhesive and other fields is of great value. In this paper, ultrafine electrolytic copper powder is used as raw material, and the experimental principle and results of direct replacement and chemical reduction are compared and analyzed. The preparation process of ultrafine silver coated copper powder by composite method was determined. The influence of dispersant and reductant on the properties of ultrafine silver coated copper powder was studied by optimizing experiments, and the kinds and dosage of complexing dispersant and reducing agent were determined. The effects of pH value of the system and the rate of silver ammonia addition on the preparation process were also studied. By means of scanning electron microscope (SEM), energy spectrometer (EDS), X-ray diffractometer (XRD), oxygen content tester, laser particle size meter, etc. The structure and properties of ultrafine silver coated copper powder were analyzed by thermogravimetric analyzer and compared with raw copper powder and ultrafine silver coated copper powder. The application of ultrafine silver coated copper powder in conductive adhesive was studied. The properties and structure of conductive adhesive with different conductive powder as conductive filler were compared. The following conclusion was drawn: in this experiment, ultrafine electrolytic copper powder was chosen as raw material for silver plating. In this paper, a composite method of replacing preplating silver and chemical reduction was established to prepare ultrafine silver coated copper powder. The chemical reagents used in the preparation of ultrafine silver coated copper powder were analyzed experimentally. In this experiment, the main reagents in the powder preparation process are determined as follows: a certain amount of EDTA-2Na as complexing dispersant, potassium tartrate as reducing agent is more suitable, by adjusting the parameters of the process, The parameters in the preparation of ultrafine silver coated copper powder were determined: the system temperature was 30 鈩，

本文編號(hào)：1598766