基于旋凝鋁合金帶的材料工藝、組織和力學(xué)性能的研究
發(fā)布時間：2018-08-01 18:12
【摘要】：本論文用旋凝方法(melt spinning)制備了7075Al條帶,用XRD、OM、SEM和TEM對旋凝態(tài)條帶和120?C、24小時時效后的旋凝條帶的微觀組織進行了分析,用顯微硬度計對上述兩種條帶的維氏硬度進行了測試。在微觀組織上,旋凝法工藝下制備7075Al微觀組織有如下特點:合金元素被過飽和的溶解于鋁基體中形成過飽和固溶體,平均晶粒尺寸為1.6?m,位錯密度達到5.7?1013 m-2;經(jīng)120?C、24小時時效后的旋凝7075Al合金條帶的微觀組織為:平均晶粒尺寸為1.7?m,位錯密度為3.7?1013 m-2,晶粒內(nèi)部含有納米級彌散的第二相。在力學(xué)性能上,旋凝態(tài)7075Al條帶維氏顯微硬度為HV50g=172,相比于傳統(tǒng)固溶處理后的粗晶7075Al合金材料,硬度提高了24%左右;經(jīng)120?C、24小時時效后的旋凝7075Al條帶的顯微硬度為HV50g=211,與經(jīng)過相同T6熱處理后的傳統(tǒng)粗晶7075Al相比,通過旋凝工藝及隨后時效處理得到的7075Al帶硬度提高了約為18%。本文基于對強化機制的分析,揭示了旋凝態(tài)7075Al硬度高于固溶處理的粗晶7075Al,120?C、24小時時效后的旋凝7075Al硬度高于固溶+120?C、24小時時效的粗晶7075Al的原因。本論文也用旋凝方法制備了5083Al合金條帶,通過對條帶進行高能球磨獲得納米晶粉末,通過高壓固結(jié)粉末制備出納米晶5083Al合金塊體材料,用XRD、SEM和TEM對粉末和塊體材料的微觀組織進行了表征,用顯微硬度計對合金塊體材料的維氏硬度進行了測試。通過球磨工藝制備出含有納米晶的5083Al粉末,平均晶粒尺寸為15.406nm,粉末顆粒尺寸為3~7?m,該粉末可用于后續(xù)的燒結(jié)工藝。通過高壓燒結(jié)在560℃下5GPa加熱3h成功制備出5083Al塊體納米材料,燒結(jié)過程中的高壓使得球磨粉末顆粒邊界氧化膜成功破碎,并且燒結(jié)塊體冶金結(jié)合良好,致密度高達99.7%;同時納米晶結(jié)構(gòu)被保留下來,其平均晶粒尺寸為80nm;顯微硬度為HV200g=241,相比傳統(tǒng)粗晶5083Al(HV=70~80)提高了300%以上,這種高強度主要歸功于細(xì)晶強化和位錯強化以及彌散強化作用;最后在拉伸斷口中韌窩的發(fā)現(xiàn),表明燒結(jié)塊體在具備高強度的同時可能具有一定的塑性。
[Abstract]:In this paper, the 7075Al bands were prepared by (melt spinning) method. The microstructure of the spin-state bands and 120-C ~ (+) C ~ (2 +) strips after 24 hours aging were analyzed by XRD-OMSEM and TEM. The Vickers hardness of the two bands were tested by microhardness meter. In microstructure, the microstructure of 7075Al prepared by spin coagulation process has the following characteristics: the alloy elements are supersaturated and dissolved in aluminum matrix to form supersaturated solid solution. The average grain size is 1.6 渭 m, dislocation density is 5.7 ~ 1013 m ~ (-2), and the microstructure of the spin-solidified 7075Al alloy strip after 24 hours aging is as follows: the average grain size is 1.7 m, the dislocation density is 3.7 ~ 1013 m ~ (-2), and the second phase with nanometer size is found in the grain. In terms of mechanical properties, the Vickers microhardness of the spin-state 7075Al strip is HV50g / 172.Compared with the coarse grained 7075Al alloy after solution treatment, the hardness is increased by about 24%. The microhardness of the 7075Al band after 24 hours aging is HV50g / 211.Compared with the traditional coarse crystalline 7075Al after the same T6 heat treatment, the hardness of the 7075Al band obtained by the spin-solidification process and the subsequent aging treatment is increased by about 18g ~ (-1) in comparison with the conventional coarse-grained 7075Al after the same T6 heat treatment. Based on the analysis of strengthening mechanism, the reason why the hardness of 7075Al in spinning state is higher than that in coarse crystal 7075 Al ~ (2 +) C ~ (2 +) after 24 hours aging is higher than that in coarse crystal 7075Al after 24 h aging in solid solution (120) C ~ (2 +) C ~ (2 +). Nanocrystalline 5083Al alloy was prepared by high energy ball milling, and nanocrystalline 5083Al alloy bulk material was prepared by high pressure consolidation powder. The microstructure of powder and bulk material was characterized by XRDX SEM and TEM. The Vickers hardness of alloy bulk material was measured by microhardness meter. The 5083Al powder containing nanocrystalline was prepared by ball milling. The average grain size was 15.406 nm and the particle size was 3 ~ 7 nm. The powder could be used in the subsequent sintering process. The 5083Al bulk nanomaterials were successfully prepared by high pressure sintering at 560 鈩，
本文編號：2158420
[Abstract]:In this paper, the 7075Al bands were prepared by (melt spinning) method. The microstructure of the spin-state bands and 120-C ~ (+) C ~ (2 +) strips after 24 hours aging were analyzed by XRD-OMSEM and TEM. The Vickers hardness of the two bands were tested by microhardness meter. In microstructure, the microstructure of 7075Al prepared by spin coagulation process has the following characteristics: the alloy elements are supersaturated and dissolved in aluminum matrix to form supersaturated solid solution. The average grain size is 1.6 渭 m, dislocation density is 5.7 ~ 1013 m ~ (-2), and the microstructure of the spin-solidified 7075Al alloy strip after 24 hours aging is as follows: the average grain size is 1.7 m, the dislocation density is 3.7 ~ 1013 m ~ (-2), and the second phase with nanometer size is found in the grain. In terms of mechanical properties, the Vickers microhardness of the spin-state 7075Al strip is HV50g / 172.Compared with the coarse grained 7075Al alloy after solution treatment, the hardness is increased by about 24%. The microhardness of the 7075Al band after 24 hours aging is HV50g / 211.Compared with the traditional coarse crystalline 7075Al after the same T6 heat treatment, the hardness of the 7075Al band obtained by the spin-solidification process and the subsequent aging treatment is increased by about 18g ~ (-1) in comparison with the conventional coarse-grained 7075Al after the same T6 heat treatment. Based on the analysis of strengthening mechanism, the reason why the hardness of 7075Al in spinning state is higher than that in coarse crystal 7075 Al ~ (2 +) C ~ (2 +) after 24 hours aging is higher than that in coarse crystal 7075Al after 24 h aging in solid solution (120) C ~ (2 +) C ~ (2 +). Nanocrystalline 5083Al alloy was prepared by high energy ball milling, and nanocrystalline 5083Al alloy bulk material was prepared by high pressure consolidation powder. The microstructure of powder and bulk material was characterized by XRDX SEM and TEM. The Vickers hardness of alloy bulk material was measured by microhardness meter. The 5083Al powder containing nanocrystalline was prepared by ball milling. The average grain size was 15.406 nm and the particle size was 3 ~ 7 nm. The powder could be used in the subsequent sintering process. The 5083Al bulk nanomaterials were successfully prepared by high pressure sintering at 560 鈩，
本文編號：2158420
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