稀土超磁致伸缩材料扬声器研制

目   录

引言......................................................................1
1  论述...................................................................3
1.1磁致伸缩来源...........................................................3
1.1.1磁致伸缩效应的来源...................................................3
1.1.2形状效应.............................................................3
1.1.3自发磁致伸缩.........................................................3
1.2 磁致伸缩效应简介......................................................3
1.2.1磁场诱发磁致伸缩.....................................................4
1.2.2磁致伸缩现象(或效应..................................................4
1.2.3磁致伸缩材料的应用主要涉几种效应.....................................4
1.2.4稀土超磁致伸缩材料...................................................4
1.3 磁致伸缩材料的制备的方法..............................................5
1.4 磁致伸缩材料的应用现状................................................6
1.4.1国外稀土磁致伸缩材料的应用现状.......................................6
1.4.2国内稀土磁致伸缩材料的应用现状.......................................7
1.5  磁致伸缩扬声器.......................................................7
1.5.1磁致伸缩扬声器结构...................................................7
1.5.2磁致伸缩扬声器工作原理...............................................7
1.5.3磁致伸缩扬声器的意义.................................................8
1.6 本论文的研究内容......................................................8
2  超磁致伸缩材料（GMM）的制备与性能测量..................................9
2.1 磁致伸缩材料的制备....................................................9
2.2 磁致伸缩材料配比......................................................9
2.3 磁致伸缩棒的制备与加工................................................9
2.4 磁致伸缩棒性能测试....................................................9
2.4.1磁致伸缩系数测试方法.................................................9
2.4.2振动元件伸缩系数测量结果.............................................10
2.4.3磁致伸缩棒的X射线衍射分析............................................11
2.3.4 磁致伸缩合金棒断口组织形貌SEM图.....................................12
3  磁致伸缩扬声器的设计...................................................14
3.1 磁致伸缩扬声器工作原理和基本结构......................................14
3.2 磁致伸缩扬声器的设计..................................................14
3.2.1磁致伸缩扬声器的设计.................................................14
3.2.2磁致伸缩扬声器的零件加工表...........................................15
3.3 磁致伸缩扬声器的功率放大器............................................16
3.3.1TDA2030功率放大器的介绍..............................................16
3.3.2TDA2030功率放大器的电路原理图........................................16
3.3.3磁致伸缩扬声器的偏置电路.............................................17
3.3.4功放电路的性能调试...................................................17
3.4 磁致伸缩扬声器的性能评价..............................................18
3.4.1衡量音箱的技术指标...................................................18
3.4.2扬声器的声音物理性能指标.............................................19
3.4.3磁致伸缩式扬声器调试.................................................19
3.5 实验结果讨论..........................................................19
3.5.1结果验证.............................................................20
3.5.2结果讨论.............................................................21
3.5.3前景展望.............................................................21
4  结论...................................................................22
谢辞......................................................................23
参考文献..................................................................24
附录......................................................................25

引言......................................................................1
1  论述...................................................................3
1.1磁致伸缩来源...........................................................3
1.1.1磁致伸缩效应的来源...................................................3
1.1.2形状效应.............................................................3
1.1.3自发磁致伸缩.........................................................3
1.2 磁致伸缩效应简介......................................................3
1.2.1磁场诱发磁致伸缩.....................................................4
1.2.2磁致伸缩现象(或效应..................................................4
1.2.3磁致伸缩材料的应用主要涉几种效应.....................................4
1.2.4稀土超磁致伸缩材料...................................................4
1.3 磁致伸缩材料的制备的方法..............................................5
1.4 磁致伸缩材料的应用现状................................................6
1.4.1国外稀土磁致伸缩材料的应用现状.......................................6
1.4.2国内稀土磁致伸缩材料的应用现状.......................................7
1.5  磁致伸缩扬声器.......................................................7
1.5.1磁致伸缩扬声器结构...................................................7
1.5.2磁致伸缩扬声器工作原理...............................................7
1.5.3磁致伸缩扬声器的意义.................................................8
1.6 本论文的研究内容......................................................8
2  超磁致伸缩材料（GMM）的制备与性能测量..................................9
2.1 磁致伸缩材料的制备....................................................9
2.2 磁致伸缩材料配比......................................................9
2.3 磁致伸缩棒的制备与加工................................................9
2.4 磁致伸缩棒性能测试....................................................9
2.4.1磁致伸缩系数测试方法.................................................9
2.4.2振动元件伸缩系数测量结果.............................................10
2.4.3磁致伸缩棒的X射线衍射分析............................................11
2.3.4 磁致伸缩合金棒断口组织形貌SEM图.....................................12
3  磁致伸缩扬声器的设计...................................................14
3.1 磁致伸缩扬声器工作原理和基本结构......................................14
3.2 磁致伸缩扬声器的设计..................................................14
3.2.1磁致伸缩扬声器的设计.................................................14
3.2.2磁致伸缩扬声器的零件加工表...........................................15
3.3 磁致伸缩扬声器的功率放大器............................................16
3.3.1TDA2030功率放大器的介绍..............................................16
3.3.2TDA2030功率放大器的电路原理图........................................16
3.3.3磁致伸缩扬声器的偏置电路.............................................17
3.3.4功放电路的性能调试...................................................17
3.4 磁致伸缩扬声器的性能评价..............................................18
3.4.1衡量音箱的技术指标...................................................18
3.4.2扬声器的声音物理性能指标.............................................19
3.4.3磁致伸缩式扬声器调试.................................................19
3.5 实验结果讨论..........................................................19
3.5.1结果验证.............................................................20
3.5.2结果讨论.............................................................21
3.5.3前景展望.............................................................21
4  结论...................................................................22
谢辞......................................................................23
参考文献..................................................................24
附录......................................................................25

摘   要

与传统磁致伸缩材料及压电陶瓷比较，稀土超磁致伸缩材料的应变大，响应快，频带宽，性能稳定等一系列优点，因而具有广泛的应用前景。随着人们对音乐品质的要求越来越高，利用超磁致伸缩材料来制作扬声器，可以兼顾高低音—真正的高保真扬声器，满足人们的对音乐的享受。高保真扬声器关键是制备磁致伸缩振动元件，再通过合理的设计扬声器的外壳，并通过匹配恰当的功率放大器来驱动，即可得到性能优异的磁致伸缩式扬声器。

本课题采用最新发展起来的一种低成本的磁致伸缩多晶合金制备技术—非自耗电弧熔炼法制备出高性能的超磁致伸缩合金棒。并以超磁致伸缩合金棒作为磁致伸缩扬声器的核心元件，设计研制磁致伸缩扬声器，包括功放电路和扬声器的机械部件等，并对其进行调试。

实验获得如下结论：（1）采用非自耗电弧熔炼技术制备出高性能的稀土超磁致伸缩合金棒材，经1100℃高温退火后，所得合金棒材在磁场强度为400kA/m时，其磁致伸缩系数达803.6×10-6；（2）利用所制备的合金棒作为电—声转换元件（磁致伸缩振子），设计并制造出一台磁致伸缩式扬声器，经调试取得一定成绩，但仍有待进较大改进；（3）研制出用于磁致伸缩扬声器的大功率功放驱动电路，输出功率约12W，且其失真小，频率响应宽。

关键词：超磁致伸缩材料；扬声器；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