硼及釔對(duì)鈦鋁合金組織性能的影響及精密鑄造工藝研究
發(fā)布時(shí)間：2019-02-22 11:08
【摘要】：熔模鑄造是制備具有工程應(yīng)用背景的TiAl合金構(gòu)件的重要生產(chǎn)方式,本文研究了硼、釔對(duì)鑄態(tài)TiAl合金的組織性能的影響,以及熱處理對(duì)TiAl合金的組織性能的影響,開展了適合TiAl合金熔模鑄造用陶瓷型殼面層材料的研究,探索了大型TiAl合金鑄件的澆注工藝,進(jìn)行了大型TiAl合金格柵件的澆注。研究發(fā)現(xiàn)Y有強(qiáng)烈的吸氧作用,Ti-45Al-5Nb-0.08Y合金的氧含量從Ti-45Al-5Nb合金的740ppm降至460ppm。微量Y的添加能夠細(xì)化Ti-45Al-5Nb合金α2/γ片層的片層間距,Ti-45Al-5Nb-0.08Y合金的片層間距從Ti-45Al-5Nb合金的580nm降至200nm。但微量Y的添加對(duì)Ti-45Al-5Nb合金晶粒尺寸的影響不明顯,含Y合金的晶粒尺寸仍約為770μm。Ti-45Al-5Nb-x Y合金中的富釔相為Y2O3相,YAl O3相和Al Y相,其中有共格關(guān)系1213]YAl O3//[101]Y2O3。添加Y可改善鑄態(tài)Ti-45Al-5Nb合金的室溫力學(xué)性能。研究發(fā)現(xiàn)B的添加可以顯著細(xì)化合金組織,0.4%B為Ti-45Al-5Nb合金鑄態(tài)組織最佳細(xì)化效果的最小B添加量。Ti-45Al-5Nb-x B合金中的硼化物為遵守[001]Bf//[001]D7b//[001]B2共格關(guān)系的三相復(fù)合條帶。B對(duì)Ti-45Al-5Nb鑄態(tài)合金的細(xì)化機(jī)制為凝固前沿的成分過冷。鑄態(tài)Ti-45Al-5Nb-0.4B合金室溫力學(xué)性能最好。研究發(fā)現(xiàn)Ti-45Al-5Nb-0.4B-x Y(x=0.02,0.04,0.06,0.08,at.%)合金中由于B和Y的復(fù)合作用,合金中硼化物為Bf相條帶與YBO3相薄片垂直生長(zhǎng),兩相之間存在如下的共格關(guān)系:[001]Bf//[010]YBO3。在YBO3相生長(zhǎng)過程中消耗了氧化釔,殘余的富釔相為Al Y和Al2Y。鑄態(tài)Ti-45Al-5Nb-0.4B-0.06Y合金的室溫力學(xué)性能最好。研究發(fā)現(xiàn)含硼、釔的TiAl合金經(jīng)過全片層熱處理,Ti-45Al-5Nb-0.4B-0.06Y合金的室溫拉伸強(qiáng)度為709MPa,伸長(zhǎng)率為0.63%。含硼、釔的TiAl合金經(jīng)過雙態(tài)熱處理,Ti-45Al-5Nb-0.4B-0.06Y合金的室溫拉伸強(qiáng)度為706MPa,伸長(zhǎng)率為0.67%。研究了鋯粘結(jié)劑、鎢粘結(jié)劑、釔粘結(jié)劑、鋁粘結(jié)劑四種粘結(jié)劑的晶化行為,確定碳酸鋯銨粘結(jié)劑、偏鎢酸銨粘結(jié)劑、釔溶膠粘結(jié)劑制備的型殼的焙燒溫度為950°C,鋁溶膠粘結(jié)劑制備的型殼的焙燒溫度為1100°C。分析了反應(yīng)界面的形貌、元素分布和顯微硬度,綜合考慮界面平直程度、粘砂層致密程度、是否有TiAl合金侵入型殼、TiAl合金基體中是否有耐火材料顆粒夾雜、反應(yīng)層厚度、粘砂層厚度、鑄件表面硬度和硬化層厚度等因素,發(fā)現(xiàn)Al-Sol+Al2O3面層型殼與TiAl合金的界面反應(yīng)最輕微,反應(yīng)層厚度僅為2μm,且無粘砂層�；谛〕叽鏣iAl合金格柵試驗(yàn)件的Pro CAST數(shù)值模擬確定工藝方案,利用模擬所得最佳參數(shù)進(jìn)行實(shí)際澆注實(shí)驗(yàn),成功制備出TiAl合金格柵試驗(yàn)件。對(duì)TiAl合金格柵試驗(yàn)件分析表明,鑄件組織均勻,從Qg圓到外邊緣無明顯變化�？s松縮孔缺陷分散分布于圓盤,模擬結(jié)果與實(shí)驗(yàn)結(jié)果吻合�；谛〕叽缭囼�(yàn)件的數(shù)值模擬和實(shí)際澆注的數(shù)據(jù),優(yōu)化了TiAl合金格柵件的澆注系統(tǒng),成功制備出高質(zhì)量的大型(Φ580×10mm)TiAl合金格柵件。
[Abstract]:Investment casting is an important method of producing TiAl alloy components with engineering application background. The effects of boron and yttrium on the microstructure and properties of as-cast TiAl alloys and the effects of heat treatment on the microstructure and properties of TiAl alloys are studied in this paper. The study of ceramic shell layer material suitable for TiAl alloy investment casting was carried out, the pouring process of large TiAl alloy casting was explored, and the pouring of large TiAl alloy grille was carried out. It was found that Y had strong oxygen absorption, and the oxygen content of Ti-45Al-5Nb-0.08Y alloy decreased from 740ppm of Ti-45Al-5Nb alloy to 460 ppm. The addition of trace Y can refine the lamellar spacing of Ti-45Al-5Nb alloy 偽 _ 2 / 緯, and the interlamellar spacing of Ti-45Al-5Nb-0.08Y alloy decreases from 580nm of Ti-45Al-5Nb alloy to 200 nm. However, the effect of trace Y addition on the grain size of Ti-45Al-5Nb alloy is not obvious. The grain size of Y containing alloy is still about Y2O3 phase, YAl O3 phase and Al Y phase in 770 渭 m.Ti-45Al-5Nb-x Y alloy. There is a coherent relation 1213] YAl O _ 3 / [101] Y _ 2O _ 3. The mechanical properties of as-cast Ti-45Al-5Nb alloy at room temperature can be improved by adding Y. It was found that the addition of B could significantly refine the microstructure of the alloy. 0.4B is the minimum B addition for the best refining effect of Ti-45Al-5Nb alloy. The borides in Ti-45Al-5Nb-x B alloy are conformable to [001] Bf// [001] D7b// [001] B2. The refining mechanism of Ti-45Al-5Nb alloy is supercooled at the front of solidification. As-cast Ti-45Al-5Nb-0.4B alloy has the best mechanical properties at room temperature. It was found that the boride in Ti-45Al-5Nb-0.4B-x Y (x 0. 02 0. 04) alloy was grown perpendicular to the Bf phase strip and the YBO3 phase sheet due to the complex action of B and Y. There is the following coherent relation between the two phases: [001] Bf// [010] YBO3. Yttrium oxide was consumed during the growth of YBO3 phase, and the residual rich phase was Al Y and Al2Y.. As-cast Ti-45Al-5Nb-0.4B-0.06Y alloy has the best mechanical properties at room temperature. It was found that the tensile strength and elongation of TiAl alloy containing boron and yttrium were 709 MPA and 0.63 respectively. The tensile strength of TiAl alloy containing boron and yttrium is 706 MPA at room temperature and the elongation is 0.67 MPA after double state heat treatment. The crystallization behavior of zirconium binder, tungsten bond agent, yttrium bond agent and aluminum bond agent was studied. The calcination temperature of the shell prepared by ammonium zirconium carbonate binder, ammonium metatungstate binder and yttrium sol adhesive was 950 擄C. The calcination temperature of the shell prepared by aluminum sol binder is 1100 擄C. The morphology, element distribution and microhardness of the reaction interface were analyzed. Considering the level of interface flatness, the density of sand layer, whether there were TiAl alloy intrusive shell, whether there were refractory particles in TiAl alloy matrix, the thickness of reaction layer was considered. It is found that the interface reaction between Al-Sol Al2O3 shell and TiAl alloy is the least, the thickness of reaction layer is only 2 渭 m, and there is no sand layer. Based on the Pro CAST numerical simulation of the small size TiAl alloy grille test piece, a practical casting experiment was carried out by using the optimum parameters obtained from the simulation, and the TiAl alloy grille test piece was successfully prepared. The analysis of TiAl alloy grille shows that the casting structure is uniform and there is no obvious change from the Qg circle to the outer edge. The defect of shrinkage is dispersed on the disk, and the simulation results are in agreement with the experimental results. Based on the numerical simulation of small size test pieces and the actual pouring data, the gating system of TiAl alloy grille was optimized, and a large (桅 580 脳 10mm) TiAl alloy grid with high quality was successfully prepared.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：TG146.2;TG249.5
本文編號(hào)：2428157
[Abstract]:Investment casting is an important method of producing TiAl alloy components with engineering application background. The effects of boron and yttrium on the microstructure and properties of as-cast TiAl alloys and the effects of heat treatment on the microstructure and properties of TiAl alloys are studied in this paper. The study of ceramic shell layer material suitable for TiAl alloy investment casting was carried out, the pouring process of large TiAl alloy casting was explored, and the pouring of large TiAl alloy grille was carried out. It was found that Y had strong oxygen absorption, and the oxygen content of Ti-45Al-5Nb-0.08Y alloy decreased from 740ppm of Ti-45Al-5Nb alloy to 460 ppm. The addition of trace Y can refine the lamellar spacing of Ti-45Al-5Nb alloy 偽 _ 2 / 緯, and the interlamellar spacing of Ti-45Al-5Nb-0.08Y alloy decreases from 580nm of Ti-45Al-5Nb alloy to 200 nm. However, the effect of trace Y addition on the grain size of Ti-45Al-5Nb alloy is not obvious. The grain size of Y containing alloy is still about Y2O3 phase, YAl O3 phase and Al Y phase in 770 渭 m.Ti-45Al-5Nb-x Y alloy. There is a coherent relation 1213] YAl O _ 3 / [101] Y _ 2O _ 3. The mechanical properties of as-cast Ti-45Al-5Nb alloy at room temperature can be improved by adding Y. It was found that the addition of B could significantly refine the microstructure of the alloy. 0.4B is the minimum B addition for the best refining effect of Ti-45Al-5Nb alloy. The borides in Ti-45Al-5Nb-x B alloy are conformable to [001] Bf// [001] D7b// [001] B2. The refining mechanism of Ti-45Al-5Nb alloy is supercooled at the front of solidification. As-cast Ti-45Al-5Nb-0.4B alloy has the best mechanical properties at room temperature. It was found that the boride in Ti-45Al-5Nb-0.4B-x Y (x 0. 02 0. 04) alloy was grown perpendicular to the Bf phase strip and the YBO3 phase sheet due to the complex action of B and Y. There is the following coherent relation between the two phases: [001] Bf// [010] YBO3. Yttrium oxide was consumed during the growth of YBO3 phase, and the residual rich phase was Al Y and Al2Y.. As-cast Ti-45Al-5Nb-0.4B-0.06Y alloy has the best mechanical properties at room temperature. It was found that the tensile strength and elongation of TiAl alloy containing boron and yttrium were 709 MPA and 0.63 respectively. The tensile strength of TiAl alloy containing boron and yttrium is 706 MPA at room temperature and the elongation is 0.67 MPA after double state heat treatment. The crystallization behavior of zirconium binder, tungsten bond agent, yttrium bond agent and aluminum bond agent was studied. The calcination temperature of the shell prepared by ammonium zirconium carbonate binder, ammonium metatungstate binder and yttrium sol adhesive was 950 擄C. The calcination temperature of the shell prepared by aluminum sol binder is 1100 擄C. The morphology, element distribution and microhardness of the reaction interface were analyzed. Considering the level of interface flatness, the density of sand layer, whether there were TiAl alloy intrusive shell, whether there were refractory particles in TiAl alloy matrix, the thickness of reaction layer was considered. It is found that the interface reaction between Al-Sol Al2O3 shell and TiAl alloy is the least, the thickness of reaction layer is only 2 渭 m, and there is no sand layer. Based on the Pro CAST numerical simulation of the small size TiAl alloy grille test piece, a practical casting experiment was carried out by using the optimum parameters obtained from the simulation, and the TiAl alloy grille test piece was successfully prepared. The analysis of TiAl alloy grille shows that the casting structure is uniform and there is no obvious change from the Qg circle to the outer edge. The defect of shrinkage is dispersed on the disk, and the simulation results are in agreement with the experimental results. Based on the numerical simulation of small size test pieces and the actual pouring data, the gating system of TiAl alloy grille was optimized, and a large (桅 580 脳 10mm) TiAl alloy grid with high quality was successfully prepared.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：TG146.2;TG249.5
【參考文獻(xiàn)】
相關(guān)期刊論文 前1條
1 王艷晶;李菲;谷艷鵬;王繼杰;杜興蒿;;Ti-45Al-8(Nb,Hf,Y)-0.2B合金的高溫抗氧化性[J];稀有金屬材料與工程;2016年01期
，本文編號(hào)：2428157
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