本文選題：Al-Cu合金　切入點(diǎn)：非晶合金孕育劑　出處：《吉林大學(xué)》2015年博士論文　論文類型：學(xué)位論文

【摘要】：隨著科技進(jìn)步、環(huán)境保護(hù)和節(jié)省資源的需求，對(duì)材料輕量化的要求越來(lái)越迫切，開(kāi)發(fā)高強(qiáng)塑性鋁合金成為國(guó)內(nèi)外科研工作者的研究熱點(diǎn)之一。而通過(guò)孕育處理細(xì)化鋁合金晶粒來(lái)提高鋁合金的力學(xué)性能是簡(jiǎn)單、常用、有效的方法之一。目前，常用的鋁合金孕育劑為晶體形態(tài)，主要有Al-Ti-B和Al-Ti-C等中間合金。而采用非晶合金作為鋁合金孕育劑的研究報(bào)道少見(jiàn)。對(duì)于非晶合金作為孕育劑細(xì)化鋁合金-Al晶粒的機(jī)制和提高強(qiáng)塑性的機(jī)制并不清楚。因此，研究非晶合金孕育對(duì)鑄造Al-Cu合金組織和強(qiáng)塑性的影響規(guī)律與機(jī)制，對(duì)開(kāi)發(fā)出新的鋁合金孕育劑、豐富鋁合金孕育理論及擴(kuò)大非晶的應(yīng)用范圍具有重要的理論意義和實(shí)際應(yīng)用價(jià)值。 本文主要圍繞非晶合金孕育對(duì)鑄造Al-Cu合金的組織細(xì)化和強(qiáng)塑性的影響規(guī)律與機(jī)制進(jìn)行研究。揭示非晶合金孕育對(duì)細(xì)化鑄造Al-Cu合金-Al晶粒的影響規(guī)律及其作用機(jī)制；不同非晶合金抗孕育衰退機(jī)制和非晶合金孕育對(duì)鑄造Al-Cu合金室溫、高溫強(qiáng)塑性的影響規(guī)律與機(jī)制。本文主要研究結(jié)果如下： 1）發(fā)現(xiàn)ZrCuAlNi、ZrCuAlNiLa、FeBSi和NiNbTi四種非晶合金細(xì)化Al-Cu合金的-Al晶粒由強(qiáng)到弱的順序?yàn)閆rCuAlNi非晶ZrCuAlNiLa非晶NiNbTi非晶FeBSi非晶，它們細(xì)化-Al晶粒的最小尺寸分別約為35m，38m，39m和41m；上述四種非晶有效孕育時(shí)間由長(zhǎng)到短的順序?yàn)镹iNbTi非晶=FeBSi非晶ZrCuAlNiLa非晶ZrCuAlNi非晶，它們的有效孕育時(shí)間分別為30min，30min，10min和3min。其中，在ZrCuAlNi非晶合金中添加稀土La元素可將ZrCuAlNi非晶的有效孕育時(shí)間從3min提高到10min。 2）揭示出非晶合金孕育Al-Cu合金中的納米θ′析出相與未孕育合金的相比，尺寸顯著減小，數(shù)量明顯增多，分布更加均勻。其機(jī)制主要為非晶合金孕育處理細(xì)化了Al-Cu合金的-Al晶粒，從而使晶界長(zhǎng)度明顯增加，這有利于合金在凝固過(guò)程中晶界處的第二相分布更加均勻。并且由于晶粒尺寸變小，使在固溶處理時(shí)第二相由晶界向晶內(nèi)的擴(kuò)散距離減小，從而使Cu原子在-Al基體中分布更加均勻。導(dǎo)致在時(shí)效過(guò)程中納米θ′析出相的析出激活能降低，使大量的納米θ′析出相能夠更加容易的同時(shí)形核、析出、生長(zhǎng)，造成納米θ′析出相生長(zhǎng)所需Cu原子的缺乏，從而限制了納米θ′析出相的生長(zhǎng)，使θ′析出相的直徑和厚度變小。 3）發(fā)現(xiàn)非晶合金孕育處理Al-Cu合金與未孕育合金相比室溫強(qiáng)度和塑性都得到了同時(shí)提高，其強(qiáng)度和斷裂應(yīng)變提高的規(guī)律與非晶合金孕育細(xì)化Al-Cu合金-Al晶粒尺寸的規(guī)律基本一致。依據(jù)強(qiáng)度和塑性綜合提高的原則，四種非晶合金孕育處理對(duì)Al-Cu合金強(qiáng)塑性同時(shí)提高由強(qiáng)到弱的規(guī)律為：(Zr55Cu30Al10Ni5)97.2La2.8孕育合金Zr55Cu30Al10Ni5孕育合金Ni60Nb25Ti15孕育合金Fe79.58B11.16Si9.26孕育合金，它們最佳的強(qiáng)度和斷裂應(yīng)變分別為536MPa和16.3%，569MPa和11.1%，531MPa和14.0%，520MPa和14.2%；分別比未孕育合金提高了14.0%和123%，19.7%和58.5%，12.9%和100%，10.6%和102%。 揭示出非晶孕育Al-Cu合金強(qiáng)塑性同時(shí)提高的主要機(jī)制是晶粒細(xì)化和納米θ′析出相細(xì)化的共同作用結(jié)果。 4）首次揭示ZrCuAlNi、ZrCuAlNiLa、FeBSi和NiNbTi四種非晶合金細(xì)化Al-Cu合金-Al晶粒的機(jī)制：四種非晶合金加入到Al-Cu合金熔體中，發(fā)生晶化，分別形成Zr2Cu、ZrCu(B2)、Fe2B和NiTi晶化相，這些晶化相可以作為-Al相異質(zhì)形核核心，，從而使-Al晶粒得到了明顯細(xì)化。提出了非晶合金能夠作為Al-Cu合金孕育劑的準(zhǔn)則：非晶合金的晶化相應(yīng)滿足作為-Al相異質(zhì)形核核心的條件。 5）揭示出FeBSi和NiNbTi非晶有效孕育時(shí)間比ZrCuAlNi非晶有效孕育時(shí)間長(zhǎng)的原因是作為-Al相異質(zhì)形核核心的Fe2B和NiTi晶化相的熔點(diǎn)高于Zr2Cu和ZrCu(B2)晶化相；在ZrCuAlNi非晶中添加稀土La元素可以把ZrCuAlNi非晶合金的有效孕育時(shí)間從3min提高到10min，這主要是由于稀土La能夠提高作為-Al相異質(zhì)形核核心的Zr2Cu和ZrCu(B2)晶化相的高溫穩(wěn)定性。 6）提出開(kāi)發(fā)Al-Cu合金長(zhǎng)效非晶合金孕育劑的準(zhǔn)則為：提高作為-Al相異質(zhì)形核核心的晶化相在Al-Cu合金熔體中的穩(wěn)定性。其途徑是提高作為-Al相異質(zhì)形核核心晶化相的熔點(diǎn)；或者通過(guò)向非晶孕育劑中添加合金元素，提高作為-Al相異質(zhì)形核核心晶化相的高溫穩(wěn)定性。 7）揭示出未孕育合金、ZrCuAlNi和ZrCuAlNiLa非晶合金孕育處理Al-Cu合金的高溫變形機(jī)制均是位錯(cuò)攀移機(jī)制。發(fā)現(xiàn)在溫度433K~493K和應(yīng)變速率10-4~10-1s-1范圍內(nèi)，非晶合金孕育處理的Al-Cu合金中的納米θ′析出相比未孕育合金中的納米θ′析出相尺寸細(xì)小，數(shù)量多，分布均勻。所以導(dǎo)致位錯(cuò)運(yùn)動(dòng)更加困難，從而使非晶合金孕育處理的Al-Cu合金的熱變形激活能明顯高于未孕育合金的。因此，ZrCuAlNi和ZrCuAlNiLa非晶合金孕育Al-Cu合金的高溫強(qiáng)塑性明顯優(yōu)于未孕育Al-Cu合金。 8）提出FeBSi非晶合金是一種細(xì)化Al-Cu合金-Al晶粒的孕育時(shí)間長(zhǎng)、細(xì)化效果好、成本低廉的孕育劑。
[Abstract]:With the progress of science and technology, environmental protection and saving resources demand for lightweight materials increasingly urgent requirements, the development of high strength plastic Aluminum Alloy has become a hot research topic at home and abroad researchers. Through inoculation Aluminum Alloy grain refinement to improve the mechanical properties of Aluminum Alloy is simple, common, one of the effective methods at present. Aluminum Alloy, commonly used as inoculant crystal morphology, mainly Al-Ti-B and Al-Ti-C master alloy. And the amorphous alloy as Aluminum Alloy inoculation agent reported rare. For the amorphous alloy as the mechanism of inoculant -Al grain refinement Aluminum Alloy and improve the mechanism of plasticity is not clear. Therefore, the research on amorphous influence and mechanism of the alloy has the casting microstructure of Al-Cu alloy and strong plasticity, to develop new Aluminum Alloy inoculant, rich Aluminum Alloy inoculation theory and expand the scope of application of amorphous out It has important theoretical significance and practical application value.
To study the influence and mechanism of this paper mainly focuses on the amorphous alloy inoculant on casting Al-Cu alloy microstructure and strong plasticity of amorphous alloy. In order to reveal the effect of inoculation rule and its mechanism for grain refinement of as cast -Al Al-Cu alloy; amorphous alloy with different resistance mechanism of inoculation and amorphous alloy casting recession inoculation on Al-Cu alloy at room temperature. High temperature and strong plastic effect rule and mechanism. The main results of this paper are as follows:
1) found that ZrCuAlNi, ZrCuAlNiLa, FeBSi and NiNbTi four kinds of amorphous alloy grain refinement of Al-Cu alloy -Al order from strong to weak ZrCuAlNi ZrCuAlNiLa amorphous amorphous amorphous amorphous NiNbTi FeBSi, their minimum size decreases the grain size of -Al were about 35m, 38m, 39m and 41m; the four amorphous effective incubation time from long to short order NiNbTi =FeBSi amorphous amorphous amorphous amorphous ZrCuAlNiLa ZrCuAlNi, effective incubation time they were 30min, 30min, 10min and 3min., in ZrCuAlNi amorphous alloy doped with rare earth element La can be effective incubation time of amorphous ZrCuAlNi increased from 3min to 10min.
2) revealed that the amorphous alloy has the Al-Cu alloy nano precipitates and without inoculation alloys' theta compared to size decreased significantly, the number increased significantly, more uniform distribution. The main mechanism for amorphous alloy modification of Al-Cu alloy grain refinement of the -Al, so that the grain length was significantly increased, the distribution of the second phase is conducive to the grain boundary of the alloy during solidification of the more uniform. And because the grain size is smaller, the solution treatment of second phase from grain boundary to intracrystalline diffusion distance decreases, so that a more uniform distribution of Cu atoms in the -Al matrix. The activation induced formation of nano precipitates' theta during aging can reduce the nano 'release of theta phase can be more easily at the same time, nucleation, precipitation, growth, caused by the lack of nano precipitates' theta required for the growth of Cu atoms, thus limiting the nano precipitates grow' theta theta ', make analysis The diameter and thickness of the phase are smaller.
3) found that the amorphous alloy Al-Cu alloy inoculation compared with non inoculation alloys at room temperature strength and ductility have been improved at the same time, the -Al grain size refinement of Al-Cu alloy strength and fracture strain increase rule and the amorphous alloys have the same rules. On the basis of breeding strength and plasticity enhance integrated principle, four kinds of non amorphous alloy modification of Al-Cu alloy with strong plasticity and improve from strong to weak law: (Zr55Cu30Al10Ni5) 97.2La2.8 alloy Zr55Cu30Al10Ni5 alloy Ni60Nb25Ti15 inoculation inoculation inoculation alloys Fe79.58B11.16Si9.26 inoculation alloys, their optimum strength and fracture strain were 536MPa and 16.3%, 569MPa and 11.1%, 531MPa and 14%, 520MPa and 14.2% respectively; inoculation alloys increased by 14% and 123%, 19.7% and 58.5%, 12.9% and 100%, 10.6% and 102%.
It is revealed that the main mechanism of increasing the strength of the amorphous Al-Cu alloy at the same time is the result of the common effect of grain refinement and the refinement of the precipitation phase of the nanoscale.
4) revealed for the first time ZrCuAlNi, ZrCuAlNiLa, FeBSi and NiNbTi four kinds of mechanism of amorphous alloy grain refinement of Al-Cu alloy -Al four amorphous alloy into Al-Cu alloy melt, crystallization, the formation of Zr2Cu, ZrCu (B2), Fe2B and NiTi phases. These phases can be used as heterogeneous nucleation of -Al the core, so that the -Al grain is obviously refined. The amorphous alloy is proposed as Al-Cu alloy inoculant criterion: the crystallization phase corresponding to meet -Al as core conditions.
5) revealed that FeBSi and NiNbTi amorphous amorphous ZrCuAlNi effective incubation time than effective inoculation causes of long time as -Al phase nuclei Fe2B and NiTi crystalline phase is higher than the melting point of Zr2Cu and ZrCu (B2) in non crystalline phase; ZrCuAlNi can effectively put the incubation time of ZrCuAlNi amorphous alloy increased from 3min to add 10min of rare earth element La crystal, which is mainly due to the rare earth La can improve -Al as heterogeneous nuclei of Zr2Cu and ZrCu (B2) high temperature stability of crystalline phase.
6) to develop long-term Al-Cu alloy amorphous alloy inoculant is the criterion for improving as the crystallization of -Al heterogeneous nucleation phase in Al-Cu alloy melt stability. The way is to improve the quality of different -Al as nucleation crystallization phase melting; or by alloying agent to the amorphous incubation, improve as the -Al phase nucleation crystallization phase stability at high temperature.
7) revealed no inoculation alloys, ZrCuAlNi and ZrCuAlNiLa amorphous alloy has the high temperature treatment of Al-Cu alloy deformation mechanism is dislocation climbing mechanism. We find that the temperature 433K~493K and strain rate range of 10-4~10-1s-1 Al-Cu alloy amorphous alloy inoculant in nano precipitation compared with no inoculation 'theta theta' nano alloy the small size, number and distribution. So the dislocation movement more difficult, the activation energy was significantly higher than that of non inoculation alloys deformation of Al-Cu alloy so that the amorphous alloy inoculant heat. Therefore, the ZrCuAlNi and ZrCuAlNiLa non high temperature amorphous alloy inoculation of the Al-Cu alloy is better than non pregnant Al-Cu alloy.
8) it is suggested that FeBSi amorphous alloy is a kind of inoculant with long inoculation time, good refining effect and low cost for refining Al-Cu alloy -Al grain.

【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類號(hào)】：TG146.21

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 ;Instability of TiC and TiAl3 compounds in Al-10Mg and Al-5Cu alloys by addition of Al-Ti-C master alloy[J];Journal of University of Science and Technology Beijing(English Edition);2006年02期

2 余貴春,張柏清,馬洪濤,李建國(guó),方鴻生,楊文言,馬曉華;鋁熱反應(yīng)制備Al-Ti-C中間合金的研究[J];金屬熱處理;2000年05期

3 李建國(guó),馬洪濤,張柏清,方鴻生,馬曉華;Al-3Ti-4B細(xì)化劑和Al-10Sr變質(zhì)劑對(duì)ZL104合金的聯(lián)合作用[J];金屬學(xué)報(bào);2000年06期

4 張作貴,劉相法,邊秀房;Al-Ti-C系中TiC形成的熱力學(xué)與動(dòng)力學(xué)研究[J];金屬學(xué)報(bào);2000年10期

5 楊成剛,國(guó)旭明,洪張飛,錢(qián)百年;電磁攪拌對(duì)2219Al-Cu合金焊縫組織及力學(xué)性能的影響[J];金屬學(xué)報(bào);2005年10期

6 劉相法，邊秀房，李輝，馬家驥;AlTiB中間合金細(xì)化效果的組織遺傳效應(yīng)[J];金屬學(xué)報(bào);1996年02期

7 燕戰(zhàn)秋,華潤(rùn)蘭;論汽車輕量化[J];汽車工程;1994年06期

8 田浩彬,林建平,劉瑞同,許永超;汽車車身輕量化及其相關(guān)成形技術(shù)綜述[J];汽車工程;2005年03期

9 李建國(guó),馬洪濤,張柏清;AlTiC和Al4B、Al3Ti4B中間合金對(duì)純鋁和亞共晶鋁硅合金的細(xì)化機(jī)理[J];輕合金加工技術(shù);2000年12期

10 馬宏聲;孝云禎;劉勁波;;鋁-鈦-硼晶粒細(xì)化機(jī)理(1)[J];輕金屬;1991年02期

相關(guān)博士學(xué)位論文 前1條

1 許春香;Al-Ti-C基中間合金的合成及其細(xì)化效果研究[D];太原理工大學(xué);2010年

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