稀土超磁致伸縮材料揚聲器研制

目   錄

引言......................................................................1
1  論述...................................................................3
1.1磁致伸縮來源...........................................................3
1.1.1磁致伸縮效應的來源...................................................3
1.1.2形狀效應.............................................................3
1.1.3自發(fā)磁致伸縮.........................................................3
1.2 磁致伸縮效應簡介......................................................3
1.2.1磁場誘發(fā)磁致伸縮.....................................................4
1.2.2磁致伸縮現(xiàn)象(或效應..................................................4
1.2.3磁致伸縮材料的應用主要涉幾種效應.....................................4
1.2.4稀土超磁致伸縮材料...................................................4
1.3 磁致伸縮材料的制備的方法..............................................5
1.4 磁致伸縮材料的應用現(xiàn)狀................................................6
1.4.1國外稀土磁致伸縮材料的應用現(xiàn)狀.......................................6
1.4.2國內(nèi)稀土磁致伸縮材料的應用現(xiàn)狀.......................................7
1.5  磁致伸縮揚聲器.......................................................7
1.5.1磁致伸縮揚聲器結構...................................................7
1.5.2磁致伸縮揚聲器工作原理...............................................7
1.5.3磁致伸縮揚聲器的意義.................................................8
1.6 本論文的研究內(nèi)容......................................................8
2  超磁致伸縮材料（GMM）的制備與性能測量..................................9
2.1 磁致伸縮材料的制備....................................................9
2.2 磁致伸縮材料配比......................................................9
2.3 磁致伸縮棒的制備與加工................................................9
2.4 磁致伸縮棒性能測試....................................................9
2.4.1磁致伸縮系數(shù)測試方法.................................................9
2.4.2振動元件伸縮系數(shù)測量結果.............................................10
2.4.3磁致伸縮棒的X射線衍射分析............................................11
2.3.4 磁致伸縮合金棒斷口組織形貌SEM圖.....................................12
3  磁致伸縮揚聲器的設計...................................................14
3.1 磁致伸縮揚聲器工作原理和基本結構......................................14
3.2 磁致伸縮揚聲器的設計..................................................14
3.2.1磁致伸縮揚聲器的設計.................................................14
3.2.2磁致伸縮揚聲器的零件加工表...........................................15
3.3 磁致伸縮揚聲器的功率放大器............................................16
3.3.1TDA2030功率放大器的介紹..............................................16
3.3.2TDA2030功率放大器的電路原理圖........................................16
3.3.3磁致伸縮揚聲器的偏置電路.............................................17
3.3.4功放電路的性能調(diào)試...................................................17
3.4 磁致伸縮揚聲器的性能評價..............................................18
3.4.1衡量音箱的技術指標...................................................18
3.4.2揚聲器的聲音物理性能指標.............................................19
3.4.3磁致伸縮式揚聲器調(diào)試.................................................19
3.5 實驗結果討論..........................................................19
3.5.1結果驗證.............................................................20
3.5.2結果討論.............................................................21
3.5.3前景展望.............................................................21
4  結論...................................................................22
謝辭......................................................................23
參考文獻..................................................................24
附錄......................................................................25

引言......................................................................1
1  論述...................................................................3
1.1磁致伸縮來源...........................................................3
1.1.1磁致伸縮效應的來源...................................................3
1.1.2形狀效應.............................................................3
1.1.3自發(fā)磁致伸縮.........................................................3
1.2 磁致伸縮效應簡介......................................................3
1.2.1磁場誘發(fā)磁致伸縮.....................................................4
1.2.2磁致伸縮現(xiàn)象(或效應..................................................4
1.2.3磁致伸縮材料的應用主要涉幾種效應.....................................4
1.2.4稀土超磁致伸縮材料...................................................4
1.3 磁致伸縮材料的制備的方法..............................................5
1.4 磁致伸縮材料的應用現(xiàn)狀................................................6
1.4.1國外稀土磁致伸縮材料的應用現(xiàn)狀.......................................6
1.4.2國內(nèi)稀土磁致伸縮材料的應用現(xiàn)狀.......................................7
1.5  磁致伸縮揚聲器.......................................................7
1.5.1磁致伸縮揚聲器結構...................................................7
1.5.2磁致伸縮揚聲器工作原理...............................................7
1.5.3磁致伸縮揚聲器的意義.................................................8
1.6 本論文的研究內(nèi)容......................................................8
2  超磁致伸縮材料（GMM）的制備與性能測量..................................9
2.1 磁致伸縮材料的制備....................................................9
2.2 磁致伸縮材料配比......................................................9
2.3 磁致伸縮棒的制備與加工................................................9
2.4 磁致伸縮棒性能測試....................................................9
2.4.1磁致伸縮系數(shù)測試方法.................................................9
2.4.2振動元件伸縮系數(shù)測量結果.............................................10
2.4.3磁致伸縮棒的X射線衍射分析............................................11
2.3.4 磁致伸縮合金棒斷口組織形貌SEM圖.....................................12
3  磁致伸縮揚聲器的設計...................................................14
3.1 磁致伸縮揚聲器工作原理和基本結構......................................14
3.2 磁致伸縮揚聲器的設計..................................................14
3.2.1磁致伸縮揚聲器的設計.................................................14
3.2.2磁致伸縮揚聲器的零件加工表...........................................15
3.3 磁致伸縮揚聲器的功率放大器............................................16
3.3.1TDA2030功率放大器的介紹..............................................16
3.3.2TDA2030功率放大器的電路原理圖........................................16
3.3.3磁致伸縮揚聲器的偏置電路.............................................17
3.3.4功放電路的性能調(diào)試...................................................17
3.4 磁致伸縮揚聲器的性能評價..............................................18
3.4.1衡量音箱的技術指標...................................................18
3.4.2揚聲器的聲音物理性能指標.............................................19
3.4.3磁致伸縮式揚聲器調(diào)試.................................................19
3.5 實驗結果討論..........................................................19
3.5.1結果驗證.............................................................20
3.5.2結果討論.............................................................21
3.5.3前景展望.............................................................21
4  結論...................................................................22
謝辭......................................................................23
參考文獻..................................................................24
附錄......................................................................25

摘   要

與傳統(tǒng)磁致伸縮材料及壓電陶瓷比較，稀土超磁致伸縮材料的應變大，響應快，頻帶寬，性能穩(wěn)定等一系列優(yōu)點，因而具有廣泛的應用前景。隨著人們對音樂品質(zhì)的要求越來越高，利用超磁致伸縮材料來制作揚聲器，可以兼顧高低音—真正的高保真揚聲器，滿足人們的對音樂的享受。高保真揚聲器關鍵是制備磁致伸縮振動元件，再通過合理的設計揚聲器的外殼，并通過匹配恰當?shù)墓β史糯笃鱽眚?qū)動，即可得到性能優(yōu)異的磁致伸縮式揚聲器。

本課題采用最新發(fā)展起來的一種低成本的磁致伸縮多晶合金制備技術—非自耗電弧熔煉法制備出高性能的超磁致伸縮合金棒。并以超磁致伸縮合金棒作為磁致伸縮揚聲器的核心元件，設計研制磁致伸縮揚聲器，包括功放電路和揚聲器的機械部件等，并對其進行調(diào)試。

實驗獲得如下結論：（1）采用非自耗電弧熔煉技術制備出高性能的稀土超磁致伸縮合金棒材，經(jīng)1100℃高溫退火后，所得合金棒材在磁場強度為400kA/m時，其磁致伸縮系數(shù)達803.6×10-6；（2）利用所制備的合金棒作為電—聲轉(zhuǎn)換元件（磁致伸縮振子），設計并制造出一臺磁致伸縮式揚聲器，經(jīng)調(diào)試取得一定成績，但仍有待進較大改進；（3）研制出用于磁致伸縮揚聲器的大功率功放驅(qū)動電路，輸出功率約12W，且其失真小，頻率響應寬。

關鍵詞：超磁致伸縮材料；揚聲器；定向凝固；TDA2030功率放大器

Abstract

Compare with the traditional magnetostriction material and the piezoelectricity ceramics, the rare earth ultra magnetostriction material strain is big, responds quickly, band width, performance stable and so on a series of merits, thus has the widespread application prospect. Is more and more high along with the people to music quality request, uses the ultra magnetostriction material to manufacture the speaker, may give dual attention to the high bass - true high fidelity speaker, satisfies the people to music enjoyment. The high fidelity speaker key prepares the magnetostriction vibration part, again through the reasonable design speaker outer covering, and actuates through the match appropriate power amplifier, then obtains the performance outstanding magnetostriction type speaker.

This topic uses the most recent development one kind of low cost the magnetostriction polytropism alloy preparation technology  must from to consume the electric arc smelting law to prepare the high performance the ultra magnetostriction alloy stick. And by the ultra magnetostriction alloy stick took the magnetostriction speaker the core part, the design and R&D magnetostriction speaker, puts the electric circuit and the speaker mechanical part including the merit and so on, and carries on the debugging to it.
The experiment obtains the following conclusion: (1) uses must from consumes the electric arc smelting technology to prepare the high performance the rare earth ultra magnetostriction alloy good material, after 1100℃ the high temperature annealing, the obtained alloy good material in the magnetic field strength is 400kA/When m, its magnetostriction coefficient reaches 803.6×10-6; (2) use prepares the alloy stick took the electricity - sound transition element (magnetostriction oscillator), designs and makes a magnetostriction type speaker, obtained certain result after the debugging, but still waited for enters improves greatly; (3) develops uses in the magnetostriction speaker the high efficiency merit putting actuates the electric circuit, output approximately 12W, also its low distortion, width frequency response.
 Keyword: giant magnetostrictive materials; loudspeaker；TDA2030 power amplifie