200840874 九、發明說明： 【發明所屬之技術領域】 鎂合金為實用金屬中比重最輕之結構用材料，具有高比強度、 高比剛性外，其散熱性、防EMI特性及回收再生性優異。其中又以 密度最低之鎂鋰合金材料之應用頗受矚目。然而，鎂鋰合金材料之 強度低，一般常用於揚聲器振動膜之LZ91 (Mgjwto/oLi-lwto/oZn) 合金，即使經軋延或等通道角擠壓(ECAE)等塑性加工，或採用熱處 f 理之改質技術強化，其抗拉強度最高也只有140MPa左右。因此，目 前鎂鋰合金材料只侷限在功能性之應用，如揚聲器用振動膜，而在 結構上之應用上則因強度低受到較大阻礙。本發明主要是藉由微量 合金元素添加，藉由晶粒細化、顆粒分散強化或加工硬化而使鎂鋰 合金材料之強度提昇，並拓展其在結構上之應用。 【先前技術】 近年來在汽車、家電及OA產業追求輕量化之潮流中，具低密 度之鎂合金的應用受到各領域的矚目。然而常溫加工性欠缺之鎂合 ί 金，一直是成型的障礙。為提高以往一般商用齡金之室溫成型性°， 曝出許多具有室溫成型性之鎮合金。其中以添加數％u，改變纽 晶構造之Mg_Li合金縣重要，而且也有朗之實績，例如揚聲^ 用振動膜。然而若欲拓展Mg_Li合金在結構上之應用，提高 合金之抗拉強度是必要的。 曰本專利號碼特開平6-49576號公報’ Mg_u合金之超塑性特 性’以及特開平8_134614號公報’超塑性錤合金材之製造方法，分 別添加Y或Si提昇鎮合金之成型性，雖室溫之成型性有些改盖^旦 強度提昇有限。而且，因製造方法_自_金屬急速冷卻凝°固方-法’除操作不易外，強度之穩定度亦較差。 6 200840874 中華民國專利號碼253869，揚聲器用鎂合金振動膜，以及中華 民國專利號碼197758，高延展性鎂合金材料製造方法，分別敘述鎂 鋰合金在振動膜之應用及鎂鋰合金之真空熔鑄方法，對於合金添加 之影響並未探討。 '' 【發明内容】 鎂鋰合金具有優異之室溫成型性，作為鎂合金展伸材(wr〇ught materials)在結構上之應用極有潛力。然而，鎂鋰合金之機械性質低 且加工硬化能力低，因此在結構上之應用拓展不易。 本發明為解決鎂鋰合金機械強度低的課題，嘗試以微量特殊合 金元素添加來改善鎂鋰合金的顯微組織，進而提昇其機械強度。 本發明之超輕量高強度鎂合金材料，係以丨〜2〇重量％鋰及〇〜2 重置％鋅之鎖鐘合金為基本組成，添加〇·⑽1〜1重量％&及/或 0.001〜1重量。/必6，以真空熔煉製作而成。 【實施方式】 實施例 1 〜3，比較例(LAZ1110 ; 11.2%Li-0.95%Al-0.43%Zn%)。 在氬氣或其他惰性氣體保護之真空爐内，將第丨表所示之合金成分 之純金屬元素及Al-Sc、Al-Be母合金材料裝入坩堝内(鋰金屬除外）， 熔解後再二次添加鋰金屬。溶湯充分攪拌後，澆鑄成直徑為2〇cm、 長度約為45cm之擠錠。 擠錠擠製條件為料溫約2HTC，模溫約200°C，擠製前鎂擠銘:置 於保溫箱均熱，溫度為300°C。擠製速度約為65sec/m，擠製成厚度 為10mm、寬度為1〇〇_之板材。此板材於523K下持溫i小時後 退火，退火後於室溫下軋延至2mm厚之板片。 比較例(LAZ1110 ; ΐΐ·2%ϋ-0·95%Α1-0·43%Ζη%)及實施例卜3 之室溫之機械性質如第1表所示。 由此，本發明之鎂鋰合金，單獨添加Sc或Be之實施例1及2 7 200840874 之抗拉強度稍為降低，但伸長率則大幅提高，尤其實施例1(添加 0.009%Sc)之伸長率更高達83%，顯示常溫之成形性佳。另一方面， 同時添加Sc與Be之鎂鋰合金之抗拉強度高達181.7MPa，比未添加 Sc或Be比較例之抗拉強度高15.2MPa。顯示添加Sc及Be之鎂鋰合 金，其抗拉強度可明顯提高10%左右。 第1表 合金組成(wt·%) 室溫之機械性質 Li A1 Zn Sc Be Mg 抗拉強度(MPa) 伸長率(％) 比較例 11.2 0.95 0.43 --- _一 Rem· 166.5 65.7 實施例1 10.4 1.02 0.66 0.009 — Rem. 140.2 83 實施例2 10.5 1.15 0.54 0.017 Rem. 144.1 76 實施例3 11.2 0.99 0.48 0.012 0.007 Rem. 181.7 66 另一方面，第1圖及第2圖分別為比較例(LAZ1110 ; 11.2%Li- 0·95%Α1-0·43%Ζηο/〇)及實施例 3(LAZ1110+Sc+Be ; 11.2%Li- 0.99% Al-0.48%Zn%-0.012%Sc-0.007%Be)之兩種鎮裡合金，經不同軋延率 (30%、60%、90%)於室溫下軋延後之拉伸試驗結果。而第2表則為 比較例與實施例1-3之常溫機械性質。由此可知，未添加Sc或Be 之比較例(LAZ1110合金），軋延率對其抗拉强度之影響不大，顯示 此合金之加工硬化能力低。反觀實施例1之添加Sc之鎂鋰合金，抗 拉强度由140.2MPa增加至173.2MPa。而實施例2之添加Be之鎮鐘 合金，抗拉强度由144.1MPa增加至176.7MPa。此外，同時添加sc 及Be之鎂鋰合金，抗拉强度更是由181.7 MPa增加至2l2.2MPa。 顯示添加Sc或Be之鎂鋰合金的加工硬化能力相當顯著，抗拉强度 隨軋延率增加而明顯提高，90%軋延率時約可提高強度20%以上。 8 200840874 第2表 比較例 實施例1 軋延率 0% 30% 60% 90% 0% 30% 60% 90% 抗拉強度 (MPa) 166.5 157.5 163.2 172.8 140.2 151.8 170.1 173.2 伸長率(％) 65.7 39.9 62.2 35.9 83 56 49 43 實施例2 實施例3 軋延率 0% 30% 60% 90% 0% 30% 60% 90% 抗拉強度 (MPa) 144.1 149.1 154.1 176.7 181.7 163.8 172.2 212.2 伸長率(％) 76 68 83 433 66 56.8 49.5 31.5 【圖式簡單說明】 第 1 圖：比較例 LAZ1110(11.2%Li-0.95%Al- 0·43%Ζη%)之鎭鋰 合金，經不同軋延率(30%、60%、90%)於室溫下軋延後之拉伸試驗 結果。 第 2 圖：實施例 3 之 LAZ1110+Sc+Be(11.2%Li-0.99%Al-0.48% Zn%-0.012〇/〇Sc-0.007%Be)之鎂鋰合金，經不同軋延率(3〇〇/〇、6〇%、 90%)於室溫下軋延後之拉伸試驗結果。 【主要元件符號說明】 無 9200840874 IX. Description of the Invention: [Technical Fields of the Invention] Magnesium alloy is a structural material having the lightest specific gravity among practical metals, and has high specific strength and high specific rigidity, and is excellent in heat dissipation, anti-EMI characteristics, and recovery and recyclability. Among them, the application of the lowest density magnesium-lithium alloy material has attracted attention. However, magnesium-lithium alloy materials have low strength and are commonly used in LZ91 (Mgjwto/oLi-lwto/oZn) alloys for speaker diaphragms, even for plastic processing such as rolling or equal channel angular extrusion (ECAE), or by heat. f The rationalization of the upgrading technology, the tensile strength is only about 140MPa. Therefore, currently magnesium-lithium alloy materials are limited to functional applications, such as diaphragms for loudspeakers, and structural applications are greatly hindered by low strength. The present invention mainly enhances the strength of the magnesium-lithium alloy material by grain refinement, particle dispersion strengthening or work hardening by adding a small amount of alloying elements, and expands its structural application. [Prior Art] In recent years, in the pursuit of lightweighting in the automotive, home appliance, and OA industries, the application of low-density magnesium alloys has attracted attention in various fields. However, magnesium alloys, which are not suitable for room temperature processing, have always been an obstacle to molding. In order to improve the room temperature formability of the conventional commercial age gold, many town alloys having room temperature formability are exposed. Among them, the Mg_Li alloy county which changes the structure of the neodymium is important by adding a few %u, and there are also achievements such as a sound film. However, if the application of the Mg_Li alloy is to be expanded, it is necessary to increase the tensile strength of the alloy. Japanese Patent Publication No. Hei 6-49576, 'Superplastic Properties of Mg_u Alloys', and Japanese Laid-Open Patent Publication No. Hei 8-134614, the manufacturing method of superplastic niobium alloy materials, respectively, are added with Y or Si to enhance the formability of the alloy, although room temperature Some of the moldability has been changed. Further, the stability of the strength is also inferior due to the manufacturing method _ _ metal rapid cooling condensing solid-method method. 6 200840874 The Republic of China Patent No. 253869, the magnesium alloy diaphragm for loudspeakers, and the Republic of China Patent No. 197758, the method for manufacturing high-ductility magnesium alloy materials, respectively describing the application of magnesium-lithium alloy in vibrating membranes and the vacuum casting method of magnesium-lithium alloys. The effect of alloy addition has not been explored. ''Invention> The magnesium-lithium alloy has excellent room temperature formability, and has great potential as a structural application of magnesium alloy wrought materials. However, magnesium-lithium alloys have low mechanical properties and low work hardening ability, so the application in structure is not easy to expand. The present invention solves the problem of low mechanical strength of a magnesium-lithium alloy, and attempts to improve the microstructure of the magnesium-lithium alloy by adding a trace amount of a special alloy element, thereby improving the mechanical strength. The ultra-lightweight high-strength magnesium alloy material of the invention is based on 丨~2〇% by weight of lithium and 〇~2, and the zinc-locked lock alloy is added as 基本·(10)1~1% by weight & and/or 0.001 to 1 weight. / must 6, made by vacuum melting. [Examples] Examples 1 to 3, Comparative Examples (LAZ1110; 11.2% Li-0.95% Al-0.43% Zn%). In a vacuum furnace protected by argon or other inert gas, the pure metal element of the alloy composition shown in Table 及 and the Al-Sc and Al-Be master alloy materials are placed in the crucible (except lithium metal), after melting, Add lithium metal twice. After the dissolved soup was thoroughly stirred, it was cast into an extruded ingot having a diameter of 2 cm and a length of about 45 cm. The extrusion conditions of the extrusion are about 2HTC, the mold temperature is about 200 °C, and the magnesium extrusion before extrusion: the soaking in the incubator, the temperature is 300 °C. The extrusion speed was about 65 sec/m, and it was extruded into a sheet having a thickness of 10 mm and a width of 1 〇〇. The sheet was annealed at 523 K for 1 hour, and annealed and rolled to a 2 mm thick sheet at room temperature. The mechanical properties of the comparative examples (LAZ1110; ΐΐ·2% ϋ-0·95% Α1-0·43% Ζη%) and the room temperature of Example 3 are shown in Table 1. Thus, in the magnesium-lithium alloy of the present invention, the tensile strengths of Examples 1 and 2 2008 2008874 in which Sc or Be were added alone were slightly lowered, but the elongation was greatly improved, especially the elongation of Example 1 (addition of 0.009% Sc). It is as high as 83%, showing good formability at room temperature. On the other hand, the tensile strength of the magnesium-lithium alloy in which Sc and Be are simultaneously added is as high as 181.7 MPa, which is 15.2 MPa higher than the tensile strength of the comparative example in which no Sc or Be is added. It shows that the magnesium-lithium alloy to which Sc and Be are added can significantly increase the tensile strength by about 10%. Alloy composition of the first table (wt·%) Mechanical properties at room temperature Li A1 Zn Sc Be Mg Tensile strength (MPa) Elongation (%) Comparative Example 11.2 0.95 0.43 --- _ a Rem· 166.5 65.7 Example 1 10.4 1.02 0.66 0.009 — Rem. 140.2 83 Example 2 10.5 1.15 0.54 0.017 Rem. 144.1 76 Example 3 11.2 0.99 0.48 0.012 0.007 Rem. 181.7 66 On the other hand, Figures 1 and 2 are comparative examples (LAZ1110; 11.2, respectively). %Li- 0·95%Α1-0·43%Ζηο/〇) and Example 3 (LAZ1110+Sc+Be; 11.2% Li-0.99% Al-0.48%Zn%-0.012%Sc-0.007%Be) Tensile test results of two townal alloys after rolling at room temperature with different rolling rates (30%, 60%, 90%). The second table is the normal temperature mechanical properties of the comparative examples and Examples 1-3. From this, it is understood that the comparative example (LAZ1110 alloy) in which Sc or Be is not added has a small influence on the tensile strength of the rolling strength, indicating that the alloy has a low work hardening ability. In contrast, the magnesium-lithium alloy added with Sc of Example 1 increased the tensile strength from 140.2 MPa to 173.2 MPa. On the other hand, in the alloy of Be of the second embodiment, the tensile strength was increased from 144.1 MPa to 176.7 MPa. In addition, the addition of sc and Be magnesium-lithium alloys increases the tensile strength from 181.7 MPa to 2l2.2 MPa. It shows that the work hardening ability of the magnesium-lithium alloy to which Sc or Be is added is remarkable, the tensile strength is remarkably improved as the rolling rate is increased, and the strength can be increased by more than 20% at the 90% rolling rate. 8 200840874 Table 2 Comparative Example Example 1 Rolling rate 0% 30% 60% 90% 0% 30% 60% 90% Tensile strength (MPa) 166.5 157.5 163.2 172.8 140.2 151.8 170.1 173.2 Elongation (%) 65.7 39.9 62.2 35.9 83 56 49 43 Example 2 Example 3 Rolling rate 0% 30% 60% 90% 0% 30% 60% 90% Tensile strength (MPa) 144.1 149.1 154.1 176.7 181.7 163.8 172.2 212.2 Elongation (%) 76 68 83 433 66 56.8 49.5 31.5 [Simple description of the diagram] Figure 1: Comparative example LAZ1110 (11.2% Li-0.95% Al-0.43% Ζ%%) bismuth lithium alloy, with different rolling rates (30%) , 60%, 90%) tensile test results after rolling at room temperature. Fig. 2: Magnesium-lithium alloy of LAZ1110+Sc+Be (11.2% Li-0.99%Al-0.48% Zn%-0.012〇/〇Sc-0.007%Be) of Example 3, with different rolling rates (3〇 〇/〇, 6〇%, 90%) tensile test results after rolling at room temperature. [Main component symbol description] None 9