【作者】 唐巍；

【导师】 王经涛； 鲍国钢； 张新平；

【作者基本信息】 南京理工大学 ， 材料工程， 2012， 硕士

【摘要】 工业雷管延期体生产环节使用了大量的重金属铅,严重污染了自然环境并对人体造成巨大危害,本文提出采用室温超细晶材料Zn-22wt.%Al共析合金替代铅来生产工业雷管延期体,实现雷管延期体的非铅化。Zn-22wt.%Al合金通过360℃、24小时的均匀化处理+水淬的热处理方式可以有效地细化晶粒,获得细小的两相组织,其平均晶粒尺寸约为0.5μm,提高了室温下的塑性变形能力。由于管材的力学性能不易测试,本文采用热挤压棒材的方法来研究挤压温度和挤压比对Zn-22wt.%Al合金室温力学性能和微观组织的影响,进而为管材的制备提供工艺参数指导。实验结果发现,在200℃C～350℃的挤压温度和8、16、32的挤压比范围内,挤压温度越低、挤压比越小,合金的晶粒越细小,越有利于实现Zn-22wt.%Al合金室温下低流变应力和高延展性,并在挤压温度200℃、挤压比为8、应变速率为10-3s-1时获得了室温下267%的延伸率和105MPa的极限抗拉强度。本文自行设计了一套管材的平面分流挤压模,并通过Deform软件对挤压过程进行了仿真模拟,结果发现焊合室高度对管材的焊合质量的影响很大,而挤压温度(200℃、250℃)的影响却不明显,当焊合室高度为8mm时管材容易出现焊缝,高度为15mm时焊合良好,并通过YJJ-500B型卧式挤压机成功制备出焊合质量良好(?)20×4.6mm的Zn-22wt.%Al合金管。拉拔实验中,将Zn-22wt.%Al合金管材由(?)18mm成功拉拔至(?)12mm,但受限于现有设备,若要继续将合金管拉拔至雷管延期体所要求的(?)4.5mm还存在一定困难,在此也提出了一系列改进措施和方法。实验同时也证明了Zn-22wt.%Al合金管在拉拔过程中不会发热过大,这一点非常适合于制备雷管延期体。总体上来看,Zn-22wt.%Al合金具有优良的可挤压性和一定的可拉拔性,将其应用于雷管延期体具有一定的研究前景和可行性,但仍需要继续探索。更多还原

【Abstract】 A great deal of lead has been used in the production links of Delay detonator body, and it does great harm to natural environment and human health, to solve this problem, this study try to use Zn-22wt.%Al eutectoid alloy with an ultrafine-grained structure at room temperature to replace lead to produce Delay detonator body in a innovative way, thus make Delay detonator body out of lead. This study included with melting alloy, heat treatment, hot extrusion, mechanical properties and microstructure analysis, porthole die design, preparation of Zn-22wt.%A1 alloy pipe, tube drawing, a set of production process.The homogenizing treatment at 360℃for 20h and quenching subsequently can effectively develop an ultrafine-grained structure in Zn-22wt.%Al casting blank, the microstructures had an equiaxed and homogeneously distributed Al-rich and Zn-rich duplex-phase and its average grain size was about 0.5μm. At the same time, the plastic deformation ability at room temperature has been greatly improved.As we know, extrusion temperature and extrusion ratio have an important impact on the properties of materials. In this article, Zn-22wt.%Al alloy samples with different microstructures and mechanical properties were obtained by hot extrusion. From the result,it is concluded that with the rise of extrusion temperature(200、250、300、350℃) and extrusion ratio (8、16、32),the flow stress is increasing while the elongation-to-failure is decreasing. When extrusion temperature is 200℃and extrusion ratio is 8,this alloy exhibited a large elongation of 267% albeit at room temperature and a rate of 10-3s-1.The porthole die of circular tube is designed and the extrusion process is simulated by Deform-3D simulation software. It is concluded that maximum welding pressure on the welding plane increase with respect to chamber height, while it is not much affected by extrusion temperature. When chamber height is 15mm,high quality pipe is prepared out at the temperature of 200℃。Compared with lead, the hardness and flow stress of Zn-22wt.%Al alloy is higher, limited to existing equipment, the drawing process can not be finished normally and confront with some difficulties. To solve this problem, this article brings forward some improvement measures。The experiment also show that Zn-22wt.%Al alloy do not generate too much heat during the drawing process, which is very suitable for producing Delay detonator body, but still need to continue to explore and research.更多还原