ADC12废屑固相再生工艺对组织和性能影响

发布时间：2018-03-12 11:48

  本文选题：ADC12铝合金　切入点：田口方法　出处：《哈尔滨理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：由于铝合金属于高性能、长寿命、使用量大、使用面广的材料,同时又易于再生利用,所以再生铝产业产生的效益最大。在我国,再生铝在全铝消费总量中所占的比例较小。铸造时浇冒口和缩孔等带来的损失达到8%。对铝锭的进一步加工过程中,还要有大约20%的金属损失。利用率不到52%。铝合金液相回收率只有40%左右,且在熔炼过程中烧损率严重,能源消耗高,对环境污染大。而采用新的废铝再生技术是一种直接将废料转化为挤出产品的技术,不涉及铝的熔化过程。本文以ADC12铝合金屑为研究对象,采用干车削工艺获得切削,以CSP工艺制备坯料。坯料的致密度直接影响组织的优劣,影响挤出件的质量。本实验利用静水力学装置、田口方法分析,研究了压坯的致密性。田口方法从工程的角度对产品的质量进行调控,重点关注工艺设计阶段如何降低产品绩效的变异。该方法能够避免不可控制的环境因素影响,采用较少的实验数最大限度的减少变异,并使得输出特性波动最小,通过考虑各参数波动对产品输出特性的影响,对影响较大的主要误差因素本身的波动进行控制来改善产品输出特性的稳定性,该方法强调的是利用信噪比(S/N)来衡量指标的波动。S/N比有三种质量特性,望小特性,望目特性以及望大特性,一般根据研究对象的特性来对其进行选择,当评估改变工艺参数对产品性能的影响时,信噪比是一种简单评估质量指示符。一般情况下,得到更好的信号时的噪音小,因此最大的信噪比将会获得最好的结果。本文所研究的质量特性为密度比,可以采用望小信噪比。通过田口方法优化CSP工艺,可知ADC12最佳压坯工艺:压制温度为250℃、压制压强为640MPa、保压时间为47s。对压坯密度影响最大的是压制温度,其次是压制压力和保压时间。本文研究了被乳化液污染的ADC12铝合金屑通过烘干工艺、固相再生工艺在400±101,保温40min挤出后通过光学显微组织分析、扫描电子显微镜、透射电镜、EDS分析。洁净的ADC12屑固相再生件抗拉强度为256MPa,延伸率为9.27%。350℃烘干的ADC12屑固相再生件抗拉强度为305MPa,延伸率为11.85%。综合力学性能明显优于洁净的ADC12屑固相再生件。通过分析烘干后残留在屑表面的乳化液蒸发,使碳残留在屑表面,通过挤出时由于压力使屑表面的氧化膜破碎,从而无定形碳进入到基体内弥散分布。350℃烘干的ADC12铝合金屑固相再生件的强化机制主要是细晶强化和弥散强化。
[Abstract]:Since aluminum alloys are of high performance, long life, large usage, wide range of use, and easy to be recycled, the recycled aluminum industry produces the greatest benefits. The loss caused by casting risers and shrinkage holes reached 80.In the further processing of aluminum ingots, the reclaimed aluminum accounted for a relatively small proportion of the total aluminum consumption. There are also about 20% metal losses. The utilization ratio is less than 52%. The liquid recovery rate of aluminum alloy is only about 40%, and the burning rate is serious and the energy consumption is high during the smelting process. The new waste aluminum regeneration technology is a kind of technology which directly converts waste material into extruded products, and does not involve the melting process of aluminum. In this paper, ADC12 aluminum alloy chip is taken as the research object, and the cutting process is obtained by dry turning process. The blank was prepared by CSP process. The density of the blank directly affected the quality of the extruded parts and the quality of the extruded parts. In this experiment, the hydrostatic device was used and the Taguchi method was used to analyze the density of the billets. The compactness of blanks is studied. Taguchi method regulates the quality of products from an engineering point of view, and focuses on how to reduce the variation of product performance in the process planning stage. This method can avoid the influence of uncontrollable environmental factors. By using fewer experiments to minimize the variation and minimize the fluctuation of the output characteristics, the effect of the fluctuation of each parameter on the output characteristics of the product is considered. In order to improve the stability of the output characteristics of the product, the fluctuation of the major error factor itself is controlled. The method emphasizes that the fluctuation of the index by S / N is measured by means of S / N), which has three quality characteristics, small characteristics. Generally speaking, the eyesight characteristics and the lookout characteristics are selected according to the characteristics of the object of study. When evaluating the effect of changing the process parameters on the product performance, the SNR is a simple evaluation quality indicator. In general, the signal-to-noise ratio (SNR) is a simple indicator for evaluating the quality of the product. The maximum signal-to-noise ratio (SNR) will be the best. The mass characteristic studied in this paper is density ratio, which can be used to optimize the CSP process by using the Taguchi method. The results show that the best process of ADC12 is: pressing temperature 250 鈩，

本文编号：1601423