本文選題：放電等離子燒結(jié) + 軟磁性復(fù)合材料�。� 參考：《長春工業(yè)大學(xué)》2015年碩士論文

【摘要】：變壓器和電感器是計算機、航空航天和自動化等電子信息領(lǐng)域主要設(shè)備的重要元件,輕薄性和高度集成化的發(fā)展趨勢,使其引起了人們的廣泛關(guān)注,這也要求軟磁鐵芯具有良好的高頻特性。目前,鐵氧體和非晶合金帶材是常用的高頻軟磁性材料。鐵氧體雖電阻率較高但飽和磁感應(yīng)強度和磁導(dǎo)率較低,非晶合金制備設(shè)備復(fù)雜,加工難度大,且其電阻率遠小于鐵氧體,仍有待改善,此外其渦流損耗也較大,并非理想的高頻軟磁材料。因此,研究開發(fā)飽和磁感應(yīng)強度高、磁導(dǎo)率大、矯頑力小、損耗低且易于成型的軟磁材料是工業(yè)發(fā)展的必然要求。軟磁性復(fù)合材料(Soft magnetic composite materials,SMCs)是指通過復(fù)合方法在鐵磁性粉末顆粒表面包覆高電阻率的物質(zhì)制備出具有高電阻率、高磁導(dǎo)率的一種軟磁性材料。SMCs的制備借助粉末冶金技術(shù)的優(yōu)勢,可顯著降低高頻渦流損耗,將在航天、軍事、電子科技以及其他領(lǐng)域得到廣泛應(yīng)用。本文通過物理包覆方法和放電等離子燒結(jié)(SPS)技術(shù),選用Fe76Si9B10P5非晶微米粉末作為基體合金,Zn0.5Ni0.5Fe2O4納米鐵氧體粉末作為包覆層,在487℃燒結(jié)制備了具有優(yōu)異軟磁性能的Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4塊體非晶軟磁復(fù)合材料。燒結(jié)樣品界面出現(xiàn)約70 nm薄層熔化結(jié)晶組織,表明燒結(jié)過程中局域瞬時高溫的存在,由此闡釋了其特殊的SPS燒結(jié)機理,由于等離子體的產(chǎn)生和新的放電通路以自蔓延模式不斷形成,在樣品內(nèi)界面處形成局域瞬時高溫,Zn0.5Ni0.5Fe2O4納米粒的尖端效應(yīng)促進了放電過程,且在電流作用下,碰撞電離也極大地促進了放電和等離子體的產(chǎn)生,由放電熱產(chǎn)生的局域瞬時高溫實現(xiàn)了Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4復(fù)合材料的燒結(jié)和致密化過程。此外,通過溶膠凝膠法和SPS技術(shù),燒結(jié)由MgO納米粉末包覆的Fe-6.5Si微米級顆粒。在600 MPa壓力下,550℃燒結(jié)制備了具有優(yōu)異軟磁性能的Fe-6.5Si/MgO塊體非晶軟磁復(fù)合材料。分析了SPS脈沖電流對燒結(jié)過程及樣品致密化的影響,脈沖電流促進了MgO絕緣顆粒間的橋接,可產(chǎn)生大量的焦耳熱促進燒結(jié)過程。對添加不同含量的MgO制備的SMCs的顯微組織、軟磁性能及力學(xué)性能進行分析,結(jié)果表明在合金材料中適量添加MgO包覆層,可制得具有良好軟磁性能的微胞SMCs,如高的電阻率、高的飽和磁感應(yīng)強度、低的矯頑力等。有望在中高頻環(huán)境下得到廣泛應(yīng)用。通過溶膠凝膠化學(xué)包覆方法制備的納米軟磁性復(fù)合材料包覆層更加均勻穩(wěn)定,厚度可控,其綜合性能更加優(yōu)異,可望廣泛適用于高性能電機、高頻變頻元件、變壓器及傳感器等軟磁性零(器)件中,以實現(xiàn)生產(chǎn)輕量化和大功率化,對現(xiàn)代工業(yè)尤其是對網(wǎng)絡(luò)通訊、軍工領(lǐng)域、電子科技產(chǎn)業(yè)具有明顯的實際意義。
[Abstract]:Transformer and inductor are important components in electronic information field, such as computer, aerospace, automation and so on. The development trend of lightness and high integration has caused people's widespread concern. This also requires that the soft magnetic core has good high frequency characteristics. At present, ferrite and amorphous alloy strip are commonly used in high frequency soft magnetic materials. Although the resistivity of ferrite is high, the saturation magnetic induction intensity and permeability are low, the preparation equipment of amorphous alloy is complex, the processing is difficult, and its resistivity is much smaller than ferrite, which still needs to be improved, in addition, its eddy current loss is also larger. Not ideal high frequency soft magnetic material. Therefore, the research and development of soft magnetic materials with high saturation magnetic induction, high permeability, low coercivity, low loss and easy forming are necessary requirements of industrial development. Soft magnetic composite material MCs is a kind of soft magnetic material with high resistivity and high permeability, which is prepared by composite method on the surface of ferromagnetic powder particles. The preparation of soft magnetic material. SMCs has the advantage of powder metallurgy technology. It will be widely used in aerospace, military, electronics and other fields. In this paper, Fe76Si9B10P5 amorphous micron powder was chosen as the coating layer of Zn0.5Ni0.5Fe2O4 nano-ferrite powder by physical coating method and spark plasma sintering (SPS) technique. Bulk Fe76Si9B10P5/Zn0.5Ni0.5Fe2O4 bulk soft magnetic composites with excellent soft magnetic properties were sintered at 487 鈩，

本文編號：1795881