阻然鎂合金耐蝕性研究

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摘    要


鎂的化學(xué)性質(zhì)活潑，非常容易氧化、燃燒，導(dǎo)致鎂合金無(wú)法在大氣條件下直接進(jìn)行熔煉和澆注。氧化燃燒現(xiàn)象一直困擾著鎂合金的生產(chǎn)，嚴(yán)重地阻礙了鎂合金產(chǎn)品的大規(guī)模應(yīng)用。目前一般采用熔劑覆蓋法和氣體保護(hù)法熔煉生產(chǎn)鎂合金，或采用半固態(tài)壓鑄成形工藝以降低作業(yè)溫度，但都存在著不少缺點(diǎn)。合金化阻燃可以提高鎂合金的生產(chǎn)效率，減少環(huán)境污染，降低生產(chǎn)成本，通過(guò)合金化的方法實(shí)現(xiàn)鎂合金的阻燃是鎂合金研究的發(fā)展方向之一。

本課題采用合金化的方法來(lái)提高鎂合金的抗氧化性能。實(shí)驗(yàn)結(jié)果表明，在ZM5鎂合金中添加經(jīng)優(yōu)化配比后的混合稀土后（混合稀土加入量為0.1%），鎂合金將不再產(chǎn)生劇烈氧化燃燒現(xiàn)象，同時(shí)合金在常溫下酸性環(huán)境或鹽中的耐蝕性能也得到了顯著提高。

混合稀土阻燃鎂合金的研究，將大大提高鎂合金的生產(chǎn)效率，減少環(huán)境污染，降低生產(chǎn)成本，促進(jìn)我國(guó)鎂合金的生產(chǎn)和應(yīng)用。同時(shí)也將為我國(guó)稀土金屬材料的開(kāi)發(fā)和應(yīng)用提供廣闊的前景，從而可以充分開(kāi)發(fā)利用我國(guó)豐富的稀土資源。




關(guān)鍵詞：ZM5鎂合金，混合稀土，阻燃性，耐蝕性


 


ABSTRACT


As the lightest constructional material, Magnesium alloy has high specific strength, high specific stiffness, good magnetic-shielding ability, good damping ability, and good mechanical property. Since its chemical character is very active, Mg alloy is prone to oxidation and burning, which makes it impossible to be melted and cast in air. Oxidation and burning of Mg alloy obstruct its application greatly. Fluxes and cover gases are currently used for the melting and production processes, and semi-solid thixocasting is also used to lower the operation temperature; but there are still many problems. Alloying is a kind of promising method of preventing Mg alloy from burning.

Alloying is used here to prevent Mg alloy from oxidation. The widely used Mg alloyZM5 is chose as the original alloy. On the surface of the molten alloy, a layer of protective film with dense structure is formed by the addition of misch metal, When 0.1% RE was added. The film prevents the penetration of oxygen and volatilization of Mg vapor, and then prevents the alloy from oxidation and burning. The oxidation process and the composition of oxide film are analyzed, which gives a clear understand of oxidation at high temperature. It can help the oxidation-proof work of other metals and alloys. Alloying can improve the production efficiency, reduce environmental pollution and lower production cost, and then increases the application of Mg alloy.

The rare earth ignition-proof Mg alloy will accelerate the production and application of Mg alloy and boost the development of magnesium industry. It will promote the development of vehicle and electronics industries, which are adopting more and more Mg alloy parts. And it will also speed up the research and application of rare earth materials and the exploration of the abundant rare earth resources in China.




Key words:  ZM5magnesium alloy, misch metal, ignition, corrosion resistance




目    錄


中文摘要 I

ABSTRACT II

1 緒論 1

1.1 鎂合金生產(chǎn)面臨的問(wèn)題 1

1.2 解決辦法及其局限性 1

1.2.1 熔劑保護(hù)法 2

1.2.2 氣體保護(hù)法 3

1.2.3 半固態(tài)成形 4

1.2.4 合金化阻燃 4

1.3 研究的目的和內(nèi)容 6

1.4 課題的意義 7

2 鎂與鎂合金 8

2.1 鎂的基本性質(zhì) 8

2.2 鎂合金的特點(diǎn) 9

2.2.1 比強(qiáng)度與比剛度 9

2.2.2 抗腐蝕性 9

2.2.3 鑄造適應(yīng)性 9

2.2.4 減震性 9

2.2.5 切削加工性 9

2.2.6 導(dǎo)熱性 10

2.2.7 電磁屏蔽性 10

2.3 常用鎂合金 10

2.3.1 Mg-Mn系合金 10

2.3.2 Mg-Al系合金 10

2.3.3 Mg-Zn系合金 11

2.3.4 Mg-RE系合金 11

2.4 鎂合金的應(yīng)用 12

2.4.1汽車零部件 12

2.4.2電子器材 13

2.4.3航空航天與軍事領(lǐng)域 13

2.4.4其他領(lǐng)域 13

3 鎂合金的氧化及合金化阻燃 14

3.1 鎂氧化的原因 14

3.1.1 Mg與氧的反應(yīng) 14

3.1.2 Mg與水的反應(yīng) 14

3.1.3 MgO結(jié)構(gòu)疏松 14

3.2 合金化阻燃 15

3.2.1熱力學(xué)條件 16

3.2.2動(dòng)力學(xué)條件 17

4 混合稀土鎂合金的耐蝕性 18

4.1試驗(yàn)設(shè)備、儀器及藥品 18

4.2實(shí)驗(yàn)方法 18

4.2.1 合金熔煉 18

4.2.2 腐蝕實(shí)驗(yàn) 18

4.3 試驗(yàn)結(jié)果與分析 19

4.3.1 實(shí)驗(yàn)現(xiàn)象 19

4.3.2 混合稀土對(duì)合金顯微組織的影響 20

4.3.3 混合稀土對(duì)ZM5合金耐蝕性的影響 20

4.3.4 腐蝕機(jī)理 22

5 結(jié)論 23

致謝 24

參考文獻(xiàn) 25