基于旋凝铝合金带的材料工艺、组织和力学性能的研究
发布时间：2018-08-01 18:12
【摘要】：本论文用旋凝方法(melt spinning)制备了7075Al条带,用XRD、OM、SEM和TEM对旋凝态条带和120?C、24小时时效后的旋凝条带的微观组织进行了分析,用显微硬度计对上述两种条带的维氏硬度进行了测试。在微观组织上,旋凝法工艺下制备7075Al微观组织有如下特点:合金元素被过饱和的溶解于铝基体中形成过饱和固溶体,平均晶粒尺寸为1.6?m,位错密度达到5.7?1013 m-2;经120?C、24小时时效后的旋凝7075Al合金条带的微观组织为:平均晶粒尺寸为1.7?m,位错密度为3.7?1013 m-2,晶粒内部含有纳米级弥散的第二相。在力学性能上,旋凝态7075Al条带维氏显微硬度为HV50g=172,相比于传统固溶处理后的粗晶7075Al合金材料,硬度提高了24%左右;经120?C、24小时时效后的旋凝7075Al条带的显微硬度为HV50g=211,与经过相同T6热处理后的传统粗晶7075Al相比,通过旋凝工艺及随后时效处理得到的7075Al带硬度提高了约为18%。本文基于对强化机制的分析,揭示了旋凝态7075Al硬度高于固溶处理的粗晶7075Al,120?C、24小时时效后的旋凝7075Al硬度高于固溶+120?C、24小时时效的粗晶7075Al的原因。本论文也用旋凝方法制备了5083Al合金条带,通过对条带进行高能球磨获得纳米晶粉末,通过高压固结粉末制备出纳米晶5083Al合金块体材料,用XRD、SEM和TEM对粉末和块体材料的微观组织进行了表征,用显微硬度计对合金块体材料的维氏硬度进行了测试。通过球磨工艺制备出含有纳米晶的5083Al粉末,平均晶粒尺寸为15.406nm,粉末颗粒尺寸为3~7?m,该粉末可用于后续的烧结工艺。通过高压烧结在560℃下5GPa加热3h成功制备出5083Al块体纳米材料,烧结过程中的高压使得球磨粉末颗粒边界氧化膜成功破碎,并且烧结块体冶金结合良好,致密度高达99.7%;同时纳米晶结构被保留下来,其平均晶粒尺寸为80nm;显微硬度为HV200g=241,相比传统粗晶5083Al(HV=70~80)提高了300%以上,这种高强度主要归功于细晶强化和位错强化以及弥散强化作用;最后在拉伸断口中韧窝的发现,表明烧结块体在具备高强度的同时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，
本文编号：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，
本文编号：2158420
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