用于高压铸造中过共晶铝合金粘膜机制的研究

发布时间：2021-10-14 13:03

　　B390合金（ASTM standard）具有良好的耐磨性和高硬度性能,广泛应用于汽车领域,如发动机缸体、活塞、制动缸体等。然而,B390合金在铸造过程中,特别是压铸过程中,易于出现粘膜现象,即合金粘连到铸造中所用的钢质模具表面。因此,在工业领域中使用B390合金的主要问题是清洁模具表面的合金引起的生产暂停,以及最终损害模具表面导致模具的失效。并且,尽管在过去人们对亚共晶铝合金（A380）的粘模机理已经进行了大量研究,但对过共晶铝合金的粘模机制却很少关注。本文的研究目的是分析过共晶铝合金的粘模机理,并找到一种能够阻碍B390合金粘模的相关方法。本研究中所用的B390合金试样,来自美国GM公司。本文首先是探究了影响粘模机制的因素,并且与过去其他研究者在粘模方面所做的工作进行了比较。基于此,将B390合金样品放置于Si-C坩埚中,通过微波反应器加热使之熔化,随后对H13钢棒进行热浸镀铝,即将钢棒放入熔体浸泡。然后将H13棒在室温下依次冷却、切割、抛光,最后使用扫描电子显微镜（SEM）对浸铝后的H13棒的截面进行形貌观察以及EDS分析。实验结果与先前的研究工作所表明的温度,时间和栅极速度对粘... 

【文章来源】：上海交通大学上海市 211工程院校 985工程院校 教育部直属院校

【文章页数】：115 页

【学位级别】：硕士

【文章目录】：
摘要
ABSTRACT
Chapter1:Introduction
Chapter2:Die Soldering Literature Background Analysis
    2.1 Background:thermal wear of high-pressure die casting dies
        2.1.1 Die characteristics and damaging causes
        2.1.2 Damaging scenarios of the die
    2.2 The die soldering mechanism
        2.2.1 Shankar's model:A six-step mechanism
        2.2.2 Han's model:the existence of a critical temperature
        2.2.3 Zhu's model:a thermodynamic energy criterion
        2.2.4 Conclusion
    2.3 Factors affecting die soldering
        2.3.1 Temperature
        2.3.2 Alloying elements in the melt
        2.3.3 Alloying elements in the die
        2.3.4 Surface condition of the die
        2.3.5 Alternative die materials
        2.3.6 Modification treatments
        2.3.7 Gate velocity
    2.4 Die coatings and surface treatments
        2.4.1 Die coatings overview
        2.4.2 Surface treatments overview
        2.4.3 Conclusion
Chapter3:Experimental Setup and Plan for Analysis of Die Soldering
    3.1 Experimental setup and plan
    3.2 Quantifying the influence of erosion
        3.2.1 Experimental setup
        3.2.2 Experimental results and discussion
Chapter4:Analysis of the Die Soldering Mechanism between H13 Tool Steel and B390 Hypereutectic Aluminum
    4.1 Intermetallic layer composition study
        4.1.1 Preliminary observations
        4.1.2 Analysis of the composition of the ternary layer
        4.1.3 Analysis of the composition of the binary layer
        4.1.4 Analysis of the expanded intermetallic layers
        4.1.5 Preliminary conclusions
    4.2 Intermetallic layer growth rate study
        4.2.1 Measurements method
        4.2.2 Growth rate study of the binary layer
        4.2.3 Growth rate study of the ternary layer
        4.2.4 Overall layer growth rate calculation
        4.2.5 Preliminary conclusions
    4.3 Discussion
        4.3.1 Diffusion modelling
        4.3.2 The influence of Si on the growth rate of the intermetallic layer
        4.3.3 The Influence of Si on the die life
    4.4 Additional experiments with A380 aluminum
        4.4.1 Experiment motivations
        4.4.2 Results and discussion
    4.5 Conclusion
Chapter5:Study on the Influence of Chromium Plating and Nitride Surface Treatment
    5.1 Experimental plan
    5.2 Results and discussion
Chapter6:Conclusion
Acknowledgements
Bibliography



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