本文選題：磁致伸縮　切入點：Fe-Ga合金　出處：《北京科技大學(xué)》2016年博士論文

【摘要】：本文以實現(xiàn)大磁致伸縮Fe-Ga合金軋制薄板的制備為目標,對Fe-Ga合會的軋制變形和薄板熱處理工藝進行了研究,以NbC第二相添加促進二次再結(jié)晶Goss{110}001織構(gòu)的發(fā)展,探索出柱狀晶板坯軋制加工制備薄板的方法,改善了合金的加工性能和薄板熱處理織構(gòu),實現(xiàn)了類似單品生長的薄板制備,沿軋制方向的最大磁致伸縮性能超過280 ppm。研究了不同NbC添加量的定向凝固Fe83Ga17合金磁性能,對添加0.1 at%NbC的Fe-Ga合金的變形行為進行了研究,并通過引入柱狀品改善了合金的加工性能。利用-步成型定向凝固技術(shù),制備出不同NbC添加量的100取向合金,發(fā)現(xiàn)添加NbC可以改善定向凝固合金100取向度,添加微量0.1 at%的合會,第二相析出少,最大磁致伸縮在15 MPa預(yù)應(yīng)力下可達335ppm,且飽和磁化場不顯著增加。添加0.1at% NbC的Fe83Ga17合金,在變形溫度超過400℃時,鍛造多晶合金的壓縮變形抗力隨溫度的升高而快速降低,對應(yīng)鍛造多晶熱軋板靜態(tài)拉伸抗拉強度也迅速降低,斷裂延伸率則顯著提高；定向凝固柱狀品通過消除橫向品界,可以顯著提高合會沿變形方向的延伸率,避免軋制過程中的橫向開裂,柱狀晶試樣及其熱軋板拉伸斷裂延伸率顯著高于鍛造多品合金及其熱軋板。探索獲得具有較優(yōu)性能的Fe-Ga合金軋制薄板熱處理工藝,研究了鍛造多品Fe-Ga合金軋制薄板熱處理過程中的再結(jié)晶行為,及熱處理工藝對織構(gòu)發(fā)展的影響。在850℃初次再結(jié)晶熱處理過程中,丫織構(gòu)先于{001}110形變織構(gòu)形核發(fā)生再結(jié)晶,初次再結(jié)晶織構(gòu)主要為Y織構(gòu)。初次再結(jié)晶后,更高溫度等溫?zé)崽幚聿荒馨l(fā)生有效的二次再結(jié)晶,而連續(xù)升溫?zé)崽幚砜梢源龠M二次再結(jié)晶Goss織構(gòu)的發(fā)展。熱處理過程中的升溫速率顯著影響二次再結(jié)晶織構(gòu)及磁致伸縮性能,在0.25℃/min附近,可以形成較強的準確位向二次再結(jié)晶Goss織構(gòu)。連續(xù)升溫?zé)崽幚砗蟮母邷責(zé)崽幚黼A段,引入流動H2有利于消除第-：相析出,同時促進{110}晶粒的生長,并伴隨磁致伸縮性能的提高。在熱軋板坯中沿軋制方向引入定向凝固柱狀晶制備軋制薄板,通過熱處理工藝的控制,實現(xiàn)了高取向度大磁致伸縮Fe-Ga薄板的制備。柱狀晶晶粒取向在形變和再結(jié)品過程中存在取向遺傳性,同時,柱狀晶的引入還可以顯著提高薄片熱處理過程中的二次再結(jié)晶。以0.1 at%NbC作為抑制劑,可以有效促進Goss品粒二次再結(jié)品,二次再結(jié)晶在連續(xù)升溫(0.25℃/min)熱處理過程中開始溫度低于950℃。連續(xù)升溫S氣氛熱處理,通過引入大量富S富Nb析出阻礙表面品界遷移,表面品粒細小且不易生長,高溫Ar/H2熱處理后,第二相析出和細小品粒完全消除,獲得類似單品的強烈Goss取向,二次再結(jié)品Goss品粒尺寸達到厘米級,樣品平均飽和磁致伸縮245±10 ppm,沿軋向不加壓條件下的最大磁致伸縮超過280 ppm。在微偏離Goss取向Fe-Ga薄片表面,磁疇呈“柳葉刀”形貌,并排列成“梳狀”,“柳葉刀”疇在磁場下的運動與磁致伸縮呈現(xiàn)顯著的對應(yīng)關(guān)系。
[Abstract]:In this paper, in order to achieve a large magnetostriction of Fe-Ga alloy rolling sheet was prepared as the goal, the rolling deformation and heat treatment process of Fe-Ga alloy sheet was studied, and promote the development of two Goss{110}001 NbC to the recrystallization texture of second phase addition, explore the method of columnar crystal slab rolling sheet fabrication, improve the alloy the processing performance and heat treatment of thin texture, to achieve a similar single product growth plate preparation, properties of directionally solidified Fe83Ga17 alloy magnetic maximum magnetostriction along the rolling direction of more than 280 ppm. of different amount of NbC, the deformation behavior of Fe-Ga alloy with 0.1 at%NbC were studied, and improve the processing performance of the alloy through the introduction of columnar products. By - step forming technology of directional solidification, prepared 100 orientation alloy with different NbC content, found that adding NbC can improve the directional solidification of alloy 100 orientation, The addition of trace 0.1 at% alloy, second phase precipitation, the maximum magnetostriction in up to 15 MPa prestressed under 335ppm, and saturated magnetic field does not increase significantly. The Fe83Ga17 alloy with 0.1at% NbC, the deformation at the temperature above 400 DEG C, forging alloy compression deformation rapidly decreased with increasing temperature and resistance. The forging of polycrystalline hot-rolled plate static tensile tensile strength decreased rapidly, the fracture elongation increased significantly; directional solidification columnar products by eliminating the transverse boundary, can significantly improve the extension will be along the direction of deformation rate, avoid transverse cracking in the rolling process, the columnar specimen and tensile fracture of hot rolled plate and the elongation rate significantly much higher than that of alloy products and hot rolled sheet rolling. Explore the heat treatment process of Fe-Ga alloy has a good performance, again by forging multi product Fe-Ga alloy rolling sheet during heat treatment The crystallization behavior, and the influence of heat treatment process on the recrystallization texture development. 850 degrees in the first heat treatment process, Ya texture prior to {001}110 texture nucleation of recrystallization, primary recrystallization texture is mainly Y texture. After primary recrystallization, high temperature heat treatment can effectively the two time crystallization, and continuous heat treatment can promote the development of the two Goss recrystallization texture. In the heat treatment process of heating rate significantly affected two times recrystallization texture and magnetostriction, near 0.25 degrees /min, can form a strong and accurate orientation two times recrystallization texture. Goss continuous rise high temperature after heat treatment the processing stage, the flow of H2 is conducive to the elimination of the phase precipitation, and the increase of {110} grain growth, and with the improvement of magnetostriction. In hot rolled slab along the rolling direction by directional solidification columnar crystal prepared by rolling The thin plates, controlled by heat treatment process, to achieve a high degree of orientation of giant magnetostrictive Fe-Ga thin plate. The preparation of columnar grain orientation on the deformation and recrystallization are orientation inherited, goods in the course of the introduction of columnar crystals can also significantly improve the sheet during heat treatment two times recrystallization. With 0.1 at%NbC as the inhibitor, can effectively promote the Goss grain two times again, two times of recrystallization during continuous heating (0.25 degrees /min) in the process of heat treatment temperature is lower than 950 DEG S. Continuous heating atmosphere heat treatment, through the introduction of a large number of rich S Nb rich precipitates hinder the migration table surface boundary, surface quality the grain is fine and not easy growth, high temperature after Ar/H2 heat treatment, the second phase precipitation and fine particle completely eliminated, similar strong orientation Goss single product, two times recrystallization grain size reached Goss centimeter, the average saturation magnetostriction 245 + 10 ppm, along the rolling direction without The maximum magnetostriction is more than 280 ppm. under the pressure condition, and the magnetic domain is "Lancet" morphology on the surface of Goss Fe-Ga thin slice. The magnetic field is arranged in "comb". The motion of the lancet domain in magnetic field is significantly corresponding to magnetostriction.

【學(xué)位授予單位】：北京科技大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TG335.5

【參考文獻】

相關(guān)期刊論文 前1條

1 Ji-Heng Li;Xue-Xu Gao;Xi-Ming Xiao;Xiao-Qian Bao;Mao-Cai Zhang;;Magnetostriction of 〈100〉 oriented Fe Ga rods with large diameter[J];Rare Metals;2015年07期

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本文編號：1724141