【作者】 李新涛；

【导师】 殷国茂； 李廷举；

【作者基本信息】 大连理工大学 ， 材料加工工程， 2006， 博士

【摘要】 近年来随着工业及国民经济的迅速发展,对冷凝管及键合线的需求量日益增加,而且对其质量及生产效率也提出了越来越高的要求。如何生产出优质管线坯,使其能够满足后续加工的要求,是提高生产效率、获得高质量管线材的技术关键。目前外场如电磁场、超声场在冶金及材料加工领域得到了大量的研究及应用,为制备高质量管线坯提供了契机。 本文以制备高质量空心白铜、紫铜管坯及Al-1%Si合金键合线坯为目的,在国家自然科学基金-上海宝钢“钢铁联合研究基金”资助的“空心金属管坯电磁连续铸造基础研究”及中国科学院精密铜管研究中心合作进行的“水平连续铸造空心铜管坯电磁改性研究”等项目的支持下进行了管、线坯水平连铸及外场改性研究。 论文主要包括以下内容: 建立了一套中试规模的空心管坯水平连铸实验装置,探索了采用铸轧法制备BFe10-1-1白铜冷凝管;根据空心BFe30-1-1白铜管坯连铸过程的凝固特点,建立了连铸过程温度场数值模拟计算模型,考察了工艺参数对空心BFe30-1-1白铜管坯成形的影响规律,在此基础上对空心BFe30-1-1白铜管坯水平连铸可行性进行了研究。结果表明: (1) 可以采用铸轧法制备BFe10-1-1白铜冷凝管;室温时BFe10-1-1白铜管坯具有良好的拉伸性能,管坯轧制温度不能超过600℃; (2) 采用水平连铸工艺可以制备出表面光滑、凝固组织致密的空心BFe30-1-1白铜管坯,其微观组织呈现典型的树枝状偏析,同时,工艺参数对空心BFe30-1-1白铜管坯质量有着重要影响。 提出空心紫铜管坯水平电磁连续铸造技术,模拟了电磁场在结晶器内的分布,设计制作了电磁成形系统并进行了空心紫铜管坯水平电磁连铸实验,考察了电磁场对空心紫铜管坯表面质量、凝固组织、力学性能及模具使用寿命的影响。结果表明,在空心紫铜管坯水平连铸过程中施加工频电磁场,可以改善管坯表面质量;细化凝固组织,明显改善组织的周向均匀性;管坯的力学性能和综合成品率得到了提高。 为改善Al-1%Si合金键合线坯质量,提出了大功率超声场作用下的水平连铸新技术。设计制作了一套水平连铸功率超声改性装置,在此设备上进行了Al-1%Si合金水平连铸实验,探讨了超声场对铸坯表面质量、凝固组织及力学性能的影响规律。结果表明:在Al-1%Si合金水平连铸过程中施加功率超声能够提高保温炉内金属液温度均匀性,显著提高铸坯表面质量;可细化晶粒,抑制Si元素在晶界的偏析;随着超声功率的增加,铸坯的力学性能得到显著的提高。更多还原

【Abstract】 In recent years, with the development of industry and national economy, the needs of high quality condenser-tubes and bonding wires increase quickly. To meet the succedent procedure, tube blanks and wire rods free from defects are needed, which is the key to improve production efficiency and obtain high-quality tubes and bonding wires. Nowadays, external fields such as electromagnetic field and power ultrasonic field are successfully applied in metallurgy and material processing, which provides a chance to produce high quality tube blanks and wire rods.The purpose of the dissertation is to produce high quality copper-nickel, pure copper tube blanks and Al-l%Si wire rods. The research is mainly supported by two projects, one is "Basic Research on Electromagnetic continuous casting of tube blanks", which is supported by Iron and Steel Cooperation Research Foundation, co-sponsored by National Natural Science Fundation and Baosteel Group Corporation;and the other is "Research on the Effect of Electromagnetic Field on Copper Tubes During Horizontal Continuous Casting", cooperated with the Research Center of Precise Copper Tube of the Chinese Academic of Science.The main contents are as follows:Horizontal continuous casting systems of pilot scale were designed to produce tube blanks. The method of casting-rolling to produce BFe10-1-1 condenser tubes was investigated. According to the solidification character of BFe30-l-l tube blanks, numerical simulation computation model of temperature field was established for simulating heat transfer during continuous casting. The influence of parameters on solidification of BFe30-1-1 tube blanks was investigated, and the feasibility of horizontal continuous casting of BFe30-l-l tube blanks was studied. It showed that:(1) BFe10-1-1 condenser tubes can be produced by casting-rolling method. The tensile properties of BFe10-1-1 tube blanks at room temperature is perfect and the maximum rolling temperature is 600℃.(2) BFe30-l-1 tube blanks with smooth surface and dense solidification structure can be obtained by horizontal continuous casting. The microstructure of cast BFe30-1-1 tube blanks is typical dendritic segregation and the quality of BFe30-l-l tube blanks is severely influenced by casting parameters.Horizontal electromagnetic continuous casting of copper tube blanks was proposed. The distribution of electromagnetic field in the mold was calculated. The electromagnetic shaping systems were designed and horizontal electromagnetic continuous casting of copper tube blanks was carried. Effects of commercial frequency electromagnetic field on surface quality, solidification structure, and mechanical properties of copper tube blanks were investigated. The results showed that surface quality can be improved by the application of electromagnetic field during horizontal continuous casting;grains are refined and distribute more uniform in the circumferential direction;Moreover, the mechanical properties and final yield are enhancedA novel process of ultrasonic treatment was proposed to improve the quality of horizontal continuously cast Al-l%Si alloy. Experimental apparatus was designed and horizontal continuous casting of Al-l%Si wire rods was conducted to investigate the effects of ultrasonic field on the surface quality, solidification structures and mechanical properties of Al-l%Si alloy. The results show that the uniformity of melt temperature and surface quality of wire rods is enhanced with the application of ultrasonic field. Grains are refined and boundary segregation of Si element is suppressed. Moreover, the tensile properties of the alloy are evidently increased with the increase of ultrasonic power.更多还原