201200602 六、發明說明： 【發明所屬之技術領域】 [0001] 本發明涉及一種鎂基複合材料及其製備方法，以及其在 發聲裝置中的應用。 - 【先前技術】 [0002] 隨著新技術和新材料的不斷發展，人們對視聽品質的要 求也越來越高。發聲裝置，如耳機、音響，產品層出不 窮，然而’先前技術中對發聲裝音質的改進多著重於其 内置揚聲器的改進，對殼體改進則較少/但殼體對音質 〇 的回應同樣很大，直接影響揚聲器的效果。 [0003] 以耳機為例，其殼體多由於共振及混響海揚聲器及整個 耳機的發聲效果造成影響，先前技術.中的耳機殼體為塑 • 膠或㈣，造成耳機發聲的崎較長，鋪的共振較強 ’發聲效果不夠清晰，使耳機存在”不好_題。另外 ，塑谬或麟的殼㈣祕不好，容易變形，並且不夠 輕巧。 Q 【發明内容】 [_ -_純合材料，包括祕金屬和分餘祕基金屬 中的奈米增強相，所述奈米增強相在鎂基複合材料中的 質量百分含量為0.01 %至2%。 _ [_—義基複合材料祕製造發聲裝置的殼體，所述錢基 複合材料包_基金屬和分散在_基金射的奈米增 強相。 闺-_基複合材料的製備方法，其包括以下步驟：提供 099120737 表單編號A0101 第3頁/共28頁 0992036588-0 201200602 鎂基金屬及奈米增強相；將奈米增強相在460°C至580°C 下加入熔融的鎂基金屬混合形成混合物；在620°C至650 °C下對該混合物進行超聲波處理使該奈米增強相均勻分 散在該鎂基金屬中；以及將該混合物在650°C至680°(:下 進行澆鑄，形成鎂基複合材料的坯體。 [〇〇〇7] 相較於先前技術，本技術方案的鎂基複合材料具有較好 的拉伸強度，可以用作發聲裝置的殼體，減少殼體產生 的混響及共振，使發聲效果清晰，從而提高發聲裝置的 音質。 【實施方式】 [0008] 以下將結合附圖詳細說明本技術方案實施例的發聲裝置 〇 [0009] 本技術方案提供一種發聲裝置，該發聲裝置包括中空的 殼體以及設置於殼體内部的揚聲器。該發聲裝置可以為 耳機、音響、喇π八、手機、筆記本電腦或電視。 [0010] 請參閱圖1，本技術方案實施方式以耳機10為例，該耳機 10包括中空的耳機殼體以及設置於殼體内部的揚聲器14 。該耳機10可以為頭戴式、耳掛式、入耳式或耳塞式等 結構。 [0011] 該揚聲器14可以為電動式、電容式、靜電式、氣動式及 壓電式等類型。該揚聲器14用於將電信號轉換成聲音信 號。具體地，揚聲器14可將一定範圍内的音頻電功率信 號通過換能方式轉變為失真小並具有足夠聲壓級的可聽 聲音。本實施例中，該揚聲器14為電動式揚聲器14。 099120737 表單編號Α0101 第4頁/共28頁 0992036588-0 201200602 [0012] 該殼體的壁厚為0. 01毫米至2毫米。該殼體可包括面對使 用者的前部12及連接導線的後部16，該前部12可進一步 包括多個出聲孔。本實施例中，該耳機為耳塞式，前部 12為具有出聲孔的圓片蓋體，後部16為與圓片蓋體扣合 的碗形基座。 [0013] ❹201200602 VI. Description of the Invention: [Technical Field of the Invention] [0001] The present invention relates to a magnesium-based composite material, a preparation method thereof, and its use in a sounding device. - [Prior Art] [0002] With the continuous development of new technologies and new materials, people's requirements for audio-visual quality are getting higher and higher. Sounding devices, such as earphones and stereos, are constantly emerging. However, the improvement in sound quality of the sounding technology in the prior art is more focused on the improvement of the built-in speaker, and the improvement on the housing is less/but the housing responds equally to the sound quality. Directly affects the effect of the speaker. [0003] Taking the earphone as an example, the housing of the earphone is mostly affected by the resonance and reverberation sea speaker and the sounding effect of the whole earphone. In the prior art, the earphone housing is plastic or rubber (4), which causes the sound of the earphone to be sounded. Long, the resonance of the shop is strong 'The sound effect is not clear enough, so the earphones are not good.' In addition, the shell of the plastic or Lin (4) is not good, easy to deform, and not lightweight enough. Q [Invention] [_ - _ homozygous material, including the nano-reinforced phase in the secret metal and the residual metal, the nano-reinforced phase in the magnesium-based composite mass percentage of 0.01% to 2%. _ [_-yiji The composite material secrets the housing of the sounding device, the money-based composite material package-based metal and the nano-enhanced phase dispersed in the _ fund. The preparation method of the 闺-_ base composite material comprises the following steps: providing a form of 099120737 No. A0101 Page 3 of 28 0992036588-0 201200602 Magnesium-based metal and nano-reinforced phase; the nano-reinforced phase is added to the molten magnesium-based metal at 460 ° C to 580 ° C to form a mixture; at 620 ° C Superheat the mixture to 650 °C The wave treatment uniformly disperses the nano reinforcing phase in the magnesium-based metal; and the mixture is cast at 650 ° C to 680 ° (: to form a green body of the magnesium-based composite material. [〇〇〇7] Compared with the prior art, the magnesium-based composite material of the technical solution has better tensile strength, can be used as a casing of the sounding device, reduces the reverberation and resonance generated by the casing, and makes the sounding effect clear, thereby improving the sounding device. [Embodiment] [0008] Hereinafter, a sound emitting device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. [0009] The present technical solution provides a sound emitting device including a hollow casing and being disposed inside the casing. The sound emitting device can be a headphone, a stereo, a mobile phone, a laptop computer or a television. [0010] Referring to FIG. 1 , the embodiment of the present invention takes the earphone 10 as an example, and the earphone 10 includes a hollow earphone. The housing and the speaker 14 disposed inside the housing. The earphone 10 can be a head-mounted, ear-hook, in-ear or earbud type. [0011] The speaker 14 can be electric , capacitive, electrostatic, pneumatic and piezoelectric, etc. The speaker 14 is used to convert an electrical signal into a sound signal. Specifically, the speaker 14 can convert a range of audio electrical power signals into a distortion through a transducing mode. The audible sound is small and has a sufficient sound pressure level. In the present embodiment, the speaker 14 is an electric speaker 14. 099120737 Form No. 1010101 Page 4 / Total 28 Page 0992036588-0 201200602 [0012] The wall thickness of the housing The housing may include a front portion 12 facing the user and a rear portion 16 connecting the wires, and the front portion 12 may further include a plurality of sound holes. In this embodiment, the earphone is of the earbud type, the front portion 12 is a wafer cover body having a sound hole, and the rear portion 16 is a bowl-shaped base that is engaged with the wafer cover body. [0013] ❹
該殼體的前部12和後部16中至少一個部分由鎂基複合材 料製成。本實施例中，該殼體整體由鎂基複合材料製成 ，即圓片蓋體與碗形基座的材料均為鎂基複合材料。該 鎂基複合材料包括鎮基金屬和分散在該鎮基金屬中的奈 米增強相。該奈米增強相可以為奈米碳管、碳化矽奈米 顆粒、氧化鋁奈米顆粒、碳化鈦奈米顆粒、碳化硼奈米 顆粒、石墨奈米顆粒或其混合，優選為奈米碳管或碳化 矽奈米顆粒。該奈米碳管可以為單壁奈米碳管、雙壁奈 米碳管及多壁奈米碳管中的一種或多種。所述單壁奈米 碳管的直徑為0. 5奈米~50奈米，所述雙壁奈米碳管的直 徑為1. 0奈米〜50奈米，所述多壁奈米碳管的直徑為1. 5 奈米〜50奈米。該奈米增強相在鎂基複合材料中的質量百 分含量約為0. 01%至10%，優選為0. 5%至2%。該奈米增強 相的形狀可以為粉末、纖維或晶須。該奈米增強相的尺 寸（即粉末、纖維或晶須的直徑）約為1奈米至100奈米 ，優選為30奈米至50奈米。該鎮基金屬為純鎮或鎂合金 。該鎂合金的組成元素除鎂外，還包括鋅、錳、鋁、鍅 、钍、鋰、銀、鈣等合金元素的一種或多種，其中鎂佔 鎂合金質量百分比80%以上，其他金屬元素的總合佔鎂合 金質量百分比20%以下。該鎂合金的型號可以為AZ91、 099120737 表單編號A0101 第5頁/共28頁 0992036588-0 201200602 AM60、AS41、AS21、AE42，優選為AZ91。 [0014] 該奈米增強相的加入有利於錢基金屬晶粒的細化，能夠 提咼該殼體的抗拉強度（tensile strength)及伸長 率（elongation)。本實施例中，該鎂基金屬採用 AZ91D型號的鎂合金’該奈米增強相採用奈米碳管或碳化 矽奈米顆粒。請參閱圖2至圖5 ’將具有質量百分比為 〇. 5%，U及1. 5%的奈米增強相的鎂基複合材料與純 AZ91D鎂合金進行晶粒對比’發現隨著奈米增強相質量百 分比在0.5%至1.5%範圍内逐漸提高，該鎂基複合材料的 B曰粒明顯減小。所述該鎮基複合材料的晶粒比用於製造 *亥鎂基複合材料的鎂基金屬的晶粒減小60%至75%。該鎂 基複。材料的晶粒約為100微米至150微米。本實施例中 田為鎂基複合材料的奈米增強相為質量百分比為〇. 至的奈米碳管時，魏基複合材料的晶粒可以比A?⑽ 、的日日粉減小6〇%至75%。請參閱圖6，當該鎂基複人 材=奈米增強相為質量百分比极5%至⑽碳化 反==化::粒之間㈣ 分含量的太+ 7，將奈切強相衫同質量百 發現基_料_拉強度測試， 鎂基複合㈣質量百分比為 祕基複合材料具有較好的抗拉強度。 [0015] 099120737 今不米增強相為不同質量八人旦 管的鎂基複合材料進行 、…的-米碳 鎮基複合材料質量百Γ4’發現當奈米碳管佔 有較好的伸長_ /比為i.5°斗魏基複合材料具 長率。上述測試表明，通過在鎂基金屬中加 表單編號A0101 第6頁/共28頁 201200602 入奈米增強相，有效地細化了晶粒，提高了鎂基複合材 料的抗拉強度及伸長率，有利於該耳機殼體的製造，並 有利於提高該耳機殼體的強度和耐用性，具體試驗資料 請參閱表1。 [0016] 表1抗拉強度及伸長率測試資料表 奈米碳 管質量 百分含 量 0°/〇 0. 01% 0. 5% 1% 1. 5% 2% 抗拉強 度 (MPa) 86 86. 5 89 96 104 90 伸長率 (%) 0. 92 0. 93 1. 1 1. 26 1. 28 0.67 [0017] 〇 ❹ [0018] 099120737 該殼體的製造方法可以為觸變成形、壓鑄成形、粉末冶 金或機械加工成形等。具體地，可將所述奈米增強相的 粉末、纖維或晶須加入熔融的鎂基金屬中，並通過觸變 成形或壓鑄成形的方法得到耳機殼體，或者可以將鎂基 金屬的粉末與奈米增強相進行混合，並通過粉末冶金的 方法製備耳機殼體，另外，也可以將所述鎂基複合材料 預先形成坯體，並通過機械加工的方式形成耳機殼體。 在本實施例中，該鎂基複合材料的製備方法包括以下步 驟： 首先，提供鎂基金屬及奈米增強相； 表單編號A0101 第7頁/共28頁 0992036588-0 [0019] 201200602 [0020] 其次，將奈米增強相在460°C至580°C下加入熔融的鎂基 金屬進行混合形成混合物； [0021] 再次，在620°C至650°C下對該混合物進行超聲波處理使 奈米增強相均勻分散在鎂基金屬中；以及 [0022] 最後，將該混合物在650°C至680°C下進行澆鑄，形成鎂 基複合材料述體。 [0023] 在上述混合、超聲波處理及澆鑄過程中的溫度分三個階 段逐漸升高，有利於使鎂基複合材料中的晶粒細化，並 且，上述過程均在保護氣體中進行，以防止鎂基金屬被 氧化。所述保護氣體可選自惰性氣體和氮氣中的一種或 多種，本實施例中保護氣體優選為為氮氣。 [0024] 具體地，該鎂基金屬可以為AZ91D鎂合金，該奈米增強相 可以為奈米碳管或碳化矽。該熔融的鎂基金屬可設置於 一内部充滿保護氣體的容器中。在將奈米增強相加入該 熔融的鎂基金屬的過程中可進一步通過攪拌器不斷對容 器中的混合物進行機械攪拌，使奈米增強相和該熔融的 鎂基金屬初步混合，得到一混合漿料。 [0025] 該超聲波處理的過程可以為將混合物連同容器置於一高 能量超聲波震盪攪拌裝置中，在一定頻率的超聲波下震 盪一段時間後，得到一均勻混合漿料。所述超聲波的頻 率為15千赫茲至20千赫茲，本實施例中超聲波的頻率優 選為15千赫茲。所述超聲波處理的時間為5分鐘至40分鐘 ，優選為30分鐘。本技術方案所採用超聲震盪的超聲波 頻率選擇為15-20千赫茲，相對於一般超聲波頻率48千赫 099120737 表單編號A0101 第8頁/共28頁 0992036588-0 201200602 雄而a，本技術方案所採用的超聲波的頻率較低，而此 超聲震盪裝置為一高能量超聲震盪攪拌裝置，因此該超 聲震逢裝置的振幅較大，因此可以使輕金屬熔湯中的輕 屬微粒發生劇烈運動，從而可以使奈米級顆粒增強體 在輕金屬料_均句分配，得到—均句混合聚料。 ' 剛錢鑄㈣程巾該混合漿财、糾至-模具巾冷卻固化 ，形成該鎂基複合材料链體。進一步地，可通過一擠壓 成型處理過程處理雜基複合材料㈣。通過該擠壓成 〇 型處理難，該奈米增_在_合物輕再次分配， 分散更加均勻，可進-步提高該複合材料的強度和 韌性。 又 剛馳體可進-步秘麟賴，_料軌體。將奈 米碳管作為奈米増強相，AZ91D鎮合金作為鎮基金屬厂且 該奈米增強相的質量百分含量為h 5%，通過壓土鱗成形去且 製備殼禮。請參閱表2，該鎮基複合材料製成的殼體與 膠殼體及AZ91D鎮合金般體相比，具有較好的屈服強产， 〇 且密度比AZ91D鎂合金有所降低。 [0028]表2不同材料殼體性能對比 [0029] 參數 塑膠 (PC+ABS) AZ9TdJI^~ ^r~~ 鎂基複合材料 密度 (g/cm3) 1.07 1. 82 ~~~~~~~~— 1. 80 屈服強度 (MPa) 39 230 ~^ 276 099120737 表單編號A0101 第9頁/共28頁 -——- 0992036588-0 201200602 在採用相同形狀殼體的條件下，對採用該鎂基複合材料 的殼體的耳機進行聲學測試，並與AZ91D鎂合金殼體的耳 機及塑膠殼體的耳機進行對比發現，採用該鎂基複合材 料的殼體制成的耳機與採用AZ91D鎂合金殼體的耳機和採 用塑膠殼體的耳機具有基本一致的頻率回應曲線及阻抗 曲線。然而，請參閱圖9，採用該鎂基複合材料的殼體制 成的耳機在三種測試的耳機中具有最小的總諧波失真。 在20赫茲至50赫茲頻率範圍内，採用鎂基複合材料的殼 體的耳機的總諧波失真比AZ91D鎂合金殼體的耳機減少約 10%° [0030] 請參閱圖10至12，從採用不同材料的殼體的瀑布分析圖 中可以看出，在20赫茲至30赫茲範圍，採用鎂基複合材 料殼體的耳機音頻振幅最低，從而使這種耳機的總諧波 失真最小，而在100赫茲至600赫茲範圍，採用鎂基複合 材料殼體的耳機比其他兩種耳機波形均一，可知這種耳 機具有發聲效果清晰的特點。 [0031] 本技術方案採用鎂基複合材料作為耳機的殼體，可以縮 短耳機發聲的混響，減少耳機殼體共振，使發聲效果清 晰，從而提高耳機的音質。並且，鎂基複合材料的殼體 比塑膠殼體更為堅固耐用，由於該殼體具有較好的強度 ，在滿足強度需要的前提下，可採用較小的壁厚，從而 減輕耳機的總體質量，並使耳機内部空間增大。另外， 鎂基複合材料具有良好的導熱性，利於耳機散熱。 [0032] 本領域技術人員可以理解，本技術方案雖然以耳機作為 具體實施例進行說明，然而由於所述殼體因製造殼體的 099120737 表單編號A0101 第10頁/共28頁 0992036588-0 201200602 材料本身具有上述優點’因此具有所述殼體的其他發聲 裝置也能具有發聲效果較好，f量較輕，堅固耐用且易 於散熱的優點。 闕、综上所述，本發财已符合發明專利之要件遂依法提 • ά專利申請。惟’以上所述者僅為本發明之較佳實施例 ，自不能以此限制本案之申請專利範圍。舉凡習知本案 技藝之人士援依本發明之精神所作之等效修飾或變化， 皆應涵蓋於以下申請專利範圍内。 g 【圖式簡單說明】 闕圖1為本技财案雜财機㈣構示意圖。 [_圖2為AZ91D鎂合金5〇倍光學顯微鏡照片： 刚圖3為具有質量百分比為Q5%的奈来增強相的鎮基複合材 料50倍光學顯微鏡照片。 [0037] 圖4為具有質量百分1:卜, 刀匕為1/〇的奈米增強相的鎂基複合材料 50倍光學顯微鏡照片。 〇剛圖5為具有質量百分比為1__奈求增強相的鎮基複合材 料50倍光學顯微鏡照片。 圃則為聽複合材射碳切與料粒介面的高解析度透 射電鏡照片。 [0040] 圖7為具有不同質量百分合署沾太， “ 3量的奈米增強相的鎂基複合材 料抗拉強度的測試資料圖。 [0041] 圖8為具有不同質量百分会吾沾太k 2 刀各量的奈朱增強相的鎂基複合材 料伸長率的測試資料圖。 099120737 表單編號A0101 第11頁/共28頁 0992036588-0 201200602 [0042] 圖9為具有不同材料的耳機殼體的耳機的總諧波失真曲線 測試資料圖。 [0043] 圖10為具有塑膠耳機殼體的耳機的瀑布分析圖。 [0044] 圖11為具有AZ91D鎂合金耳機殼體的耳機的瀑布分析圖。 [0045] 圖12為具有鎂基複合材料耳機殼體的耳機的瀑布分析圖 〇 【主要元件符號說明】 [0046] 耳機：10 [0047] 前部：12 [0048] 揚聲器：14 [0049] 後部：16 0992036588-0 099120737 表單編號A0101 第12頁/共28頁At least one of the front portion 12 and the rear portion 16 of the housing is made of a magnesium-based composite material. In this embodiment, the housing is entirely made of a magnesium-based composite material, that is, the material of the wafer cover body and the bowl-shaped base is a magnesium-based composite material. The magnesium-based composite material includes a town-based metal and a nano-reinforced phase dispersed in the town-based metal. The nano reinforcing phase may be a carbon nanotube, a cerium carbide nanoparticle, an alumina nanoparticle, a titanium carbide nanoparticle, a boron carbide nanoparticle, a graphite nanoparticle or a mixture thereof, preferably a carbon nanotube. Or carbonized nano particles. The carbon nanotubes may be one or more of a single-walled carbon nanotube, a double-walled carbon nanotube, and a multi-walled carbon nanotube. The nano-walled carbon nanotubes having a diameter of from 0.5 nm to 50 nm, and the double-walled carbon nanotubes having a diameter of 1.0 nm to 50 nm, the multi-walled carbon nanotubes The diameter is 1. 5 nm ~ 50 nm. 5%至2%。 The 5% to 2%, preferably from 0.5% to 2%. The nano reinforcing phase may be in the form of a powder, fiber or whisker. The size of the nano-enhanced phase (i.e., the diameter of the powder, fiber or whisker) is from about 1 nm to about 100 nm, preferably from 30 nm to 50 nm. The town base metal is pure town or magnesium alloy. The magnesium alloy includes, in addition to magnesium, one or more alloying elements such as zinc, manganese, aluminum, lanthanum, cerium, lithium, silver, calcium, etc., wherein magnesium accounts for more than 80% by mass of the magnesium alloy, and other metal elements The total amount of magnesium alloy is less than 20% by mass. The model of the magnesium alloy may be AZ91, 099120737 Form No. A0101 Page 5 of 28 0992036588-0 201200602 AM60, AS41, AS21, AE42, preferably AZ91. [0014] The addition of the nano reinforcing phase facilitates the refinement of the carbon-based metal grains and enhances the tensile strength and elongation of the shell. In this embodiment, the magnesium-based metal is a magnesium alloy of the AZ91D type. The nano reinforcing phase is made of a carbon nanotube or a carbonized nanoparticle. Please refer to Figure 2 to Figure 5 for the grain contrast of a magnesium-based composite with a mass percentage of 〇. 5%, U and 1.5% of the nano-reinforced phase with pure AZ91D magnesium alloy. The phase mass percentage gradually increases in the range of 0.5% to 1.5%, and the B-grain of the magnesium-based composite material is remarkably reduced. The grain of the town-base composite is reduced by 60% to 75% compared to the grain of the magnesium-based metal used to make the *Mg-based composite. The magnesium base is complex. The grains of the material are from about 100 microns to 150 microns. In this embodiment, the nano-reinforced phase of the magnesium-based composite material is a mass percentage of 奈. to the carbon nanotubes, the grain size of the Wei-based composite material can be reduced by 6% compared with the daily powder of A?(10). Up to 75%. Please refer to Figure 6, when the magnesium-based compound material = nano-enhancement phase is 5% by mass to (10) carbonization inverse == chemical:: between the grains (four) points content of too + 7, will be Niche strong shirt with the same quality It was found that the base_material tensile strength test and the magnesium-based composite (four) mass percentage have better tensile strength for the secret base composite. [0015] 099120737 The current phase of the magnesium-based composite material of different quality eight-person tube is carried out, and the mass of the carbon-based matrix composite material is found to be good when the carbon nanotubes occupy a good elongation _ / ratio For the i.5° bucket Weiji composite material has a long rate. The above test shows that by adding the nano-enhancement phase to the magnesium-based metal, the form number A0101, page 6 / page 28, 201200602, the grain is effectively refined, and the tensile strength and elongation of the magnesium-based composite material are improved. It is beneficial to the manufacture of the earphone housing and is beneficial to improving the strength and durability of the earphone housing. Please refer to Table 1 for specific test data. [0016] Table 1 tensile strength and elongation test data sheet carbon nanotube mass percentage 0 ° / 〇 0. 01% 0. 5% 1% 1. 5% 2% tensile strength (MPa) 86 86 5 89 96 104 90 Elongation (%) 0. 92 0. 93 1. 1 1. 26 1. 28 0.67 [0017] 〇❹ [0018] 099120737 The housing can be manufactured by thixoforming and die casting. , powder metallurgy or mechanical forming. Specifically, the powder, fiber or whisker of the nano reinforcing phase may be added to the molten magnesium-based metal, and the earphone casing may be obtained by a thixoforming or die casting method, or the magnesium-based metal powder may be obtained. The earphone housing is prepared by a powder metallurgy method by mixing with the nano reinforcing phase. Alternatively, the magnesium-based composite material may be preformed into a blank body, and the earphone housing may be formed by mechanical processing. In this embodiment, the method for preparing the magnesium-based composite material comprises the following steps: First, providing a magnesium-based metal and a nano-reinforcing phase; Form No. A0101, page 7 of 28 pages 0992036588-0 [0019] 201200602 [0020] Next, the nano reinforcing phase is added to the molten magnesium-based metal at 460 ° C to 580 ° C to form a mixture; [0021] Again, the mixture is ultrasonicated at 620 ° C to 650 ° C to make the nano The reinforcing phase is uniformly dispersed in the magnesium-based metal; and [0022] Finally, the mixture is cast at 650 ° C to 680 ° C to form a magnesium-based composite body. [0023] The temperature in the above mixing, ultrasonic treatment, and casting process is gradually increased in three stages, which is advantageous for refining crystal grains in the magnesium-based composite material, and the above processes are all performed in a protective gas to prevent The magnesium-based metal is oxidized. The shielding gas may be selected from one or more of an inert gas and nitrogen, and the shielding gas in this embodiment is preferably nitrogen. [0024] Specifically, the magnesium-based metal may be an AZ91D magnesium alloy, and the nano reinforcing phase may be a carbon nanotube or a tantalum carbide. The molten magnesium-based metal may be disposed in a container filled with a protective gas. In the process of adding the nano reinforcing phase to the molten magnesium-based metal, the mixture in the vessel may be further mechanically stirred by a stirrer to initially mix the nano reinforcing phase and the molten magnesium-based metal to obtain a mixed pulp. material. [0025] The ultrasonic treatment may be performed by placing the mixture together with the container in a high-energy ultrasonic vibration stirring device, and shaking for a period of time under ultrasonic waves of a certain frequency to obtain a uniform mixed slurry. The frequency of the ultrasonic waves is from 15 kHz to 20 kHz, and the frequency of the ultrasonic waves in this embodiment is preferably 15 kHz. The time of the ultrasonic treatment is from 5 minutes to 40 minutes, preferably 30 minutes. The ultrasonic frequency of the ultrasonic vibration used in the technical solution is selected to be 15-20 kHz, compared with the general ultrasonic frequency of 48 kHz 099120737 Form No. A0101 Page 8 / Total 28 Page 0992036588-0 201200602 Male and a, this technical solution is adopted The ultrasonic wave has a low frequency, and the ultrasonic oscillating device is a high-energy ultrasonic oscillating agitating device, so that the amplitude of the ultrasonic oscillating device is large, so that the light particles in the light metal melting soup can be vigorously moved, thereby enabling The nano-sized particle reinforcements are distributed in the light metal material _ uniform sentence to obtain a uniform mixed polymer. 'Gang Qianzhu (four) Cheng towel, the mixed pulp, corrected - mold towel cooling and solidification, forming the magnesium-based composite material chain. Further, the hetero-based composite material (4) can be processed by an extrusion molding process. It is difficult to handle the 成 type by the extrusion, and the nano _ _ compound is lightly redistributed, and the dispersion is more uniform, and the strength and toughness of the composite can be further improved. And just the body can enter - step secret Lin Lai, _ track body. The carbon nanotubes were used as the nano 増 strong phase, the AZ91D town alloy was used as the town-based metal plant, and the nano-reinforced phase had a mass percentage of h 5%, which was formed by compacting scales and prepared for shells. Referring to Table 2, the shell made of the matrix-based composite material has better yield and yield than the rubber shell and the AZ91D town alloy, and the density is lower than that of the AZ91D magnesium alloy. [0028] Table 2 different material shell performance comparison [0029] parameter plastic (PC + ABS) AZ9TdJI ^ ~ ^ r ~ ~ magnesium-based composite material density (g / cm3) 1.07 1. 82 ~~~~~~~~ — 1. 80 Yield strength (MPa) 39 230 ~^ 276 099120737 Form No. A0101 Page 9 of 28--- 0992036588-0 201200602 Under the condition of the same shape of the shell, the use of the magnesium-based composite material The earphones of the housing were acoustically tested and compared with the earphones of the AZ91D magnesium alloy casing and the earphones of the plastic casing. The earphones made of the magnesium matrix composite casing and the earphones using the AZ91D magnesium alloy casing were found. Headphones with a plastic housing have a substantially uniform frequency response curve and impedance curve. However, referring to Fig. 9, the earphone made of the housing of the magnesium-based composite material has the smallest total harmonic distortion in the three tested headphones. In the frequency range of 20 Hz to 50 Hz, the total harmonic distortion of the earphones of the housing using the magnesium-based composite material is reduced by about 10% compared to the earphones of the AZ91D magnesium alloy casing. [0030] Please refer to Figures 10 to 12, In the waterfall analysis of the shells of different materials, it can be seen that in the range of 20 Hz to 30 Hz, the headphone audio amplitude of the magnesium-based composite housing is the lowest, so that the total harmonic distortion of the earphone is minimized, and at 100 In the Hertz to 600 Hz range, the earphones with the magnesium-based composite casing are more uniform than the other two types of earphones, and it is known that the earphones have the characteristics of clear sounding effect. [0031] The technical solution adopts a magnesium-based composite material as a casing of the earphone, which can shorten the reverberation of the earphone sound, reduce the resonance of the earphone casing, and make the sounding effect clear, thereby improving the sound quality of the earphone. Moreover, the shell of the magnesium-based composite material is more durable and durable than the plastic shell. Since the shell has good strength, a small wall thickness can be adopted under the premise of meeting the strength requirement, thereby reducing the overall quality of the earphone. And increase the internal space of the headphones. In addition, the magnesium-based composite material has good thermal conductivity, which is advantageous for heat dissipation of the earphone. [0032] It will be understood by those skilled in the art that although the present invention is described with the earphone as a specific embodiment, since the housing is manufactured by the 099120737 form number A0101, page 10 / 28 pages 0992036588-0 201200602 material It has the above advantages itself. Therefore, other sounding devices having the casing can also have the advantages of better sounding effect, lighter weight, durability, and easy heat dissipation. In summary, the above-mentioned wealth has already met the requirements of the invention patent, and the patent application was filed according to law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by those skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims. g [Simple description of the diagram] Figure 1 is a schematic diagram of the structure of the financial scheme (four). [_ Figure 2 is a 5x optical microscopy of AZ91D magnesium alloy: Just as Figure 3 is a 50x optical micrograph of an anisotropic composite with a mass percentage of Q5%. 4 is a 50x optical micrograph of a magnesium-based composite material having a nanometer-enhanced phase with a mass percent of 1:b and a knives of 1/〇. Fig. 5 is a 50x optical microscope photograph of an anisotropic composite material having a mass percentage of 1__ to enhance the phase. The 圃 is a high-resolution transmission electron micrograph of the composite carbon-cutting and grain-filling interface. [0040] FIG. 7 is a test data diagram of the tensile strength of a magnesium-based composite material having three masses of nano-reinforcing phase, which is different in mass spectrometry. [0041] FIG. 8 is a graph of different mass percentages. Test data for the elongation of the magnesium-based composite of the Naiju reinforcing phase of each k 2 knife. 099120737 Form No. A0101 Page 11 of 28 0992036588-0 201200602 [0042] Figure 9 is a headset with different materials Figure 19 is a waterfall analysis diagram of a headphone with a plastic earphone housing. [0044] Figure 11 is an earphone with an AZ91D magnesium alloy earphone housing. [0045] FIG. 12 is a waterfall analysis diagram of a headphone housing having a magnesium-based composite earphone housing [Main component symbol description] [0046] Headphones: 10 [0047] Front: 12 [0048] Speaker: 14 [0049] Rear: 16 0992036588-0 099120737 Form No. A0101 Page 12 of 28