New Inclusion Assessment Method in Aluminum Alloys-Electrochemical Method for Inclusion Assessment

来源 :中国机械工程学报 | 被引量 : 0次 | 上传用户:wangxingchuang
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The existence of inclusion influences the properties of aluminum alloy castings,from which the castings will face scrapping under severe condition.Great efforts on the inclusions in aluminum alloy were made and many inclusion assessment methods were put forward.However,most of the current methods are characterized by time consuming and expensive equipment cost,which limits the application in aluminum industry.Since the aluminum properties are sensitive to the inclusion,this paper tries to establish a new kind of inclusion assessment method.The inclusions were introduced to aluminum melts by adding aluminum scraps.The samples with different inclusion contents were prepared.The microstructure contained inclusions was observed.The inclusion was automatically identified with an image analyzer by setting different grey threshold value,and the inclusion content was obtained.The image analysis shows that inclusions wreck the continuity of the alloy matrix seriously,and the inclusion area percentage increases with the increasing of aluminum scraps.The high and low polarization measurements were conducted in 3.5 wt% NaCI aqueous solution at the temperature of 25℃.The electrochemical parameters of the testing materials,such as corrosion potential Ek,corrosion current density Ik and the linear polarization resistance Rp,were obtained.The polarization measurement results show that the linear polarization resistances decrease,the corrosion potentials move towards more negative direction,and the corrosion current densities increase with the increasing of inclusion content.The theoretical analysis of the inclusion content and the corrosion current density was performed.The existence of inclusions makes the microstructure form corrosion microcells between the alloy matrix and inclusions.The impressed current can accelerate the current velocity or corrosion current density.The regression model of the inclusion contents vs.the corrosion current density was obtained.This model can be used to quantitatively analyze the inclusion content in aluminum alloys on the basis of inclusion sensitivity to the inclusion content.It is confirmed that the electrochemical method for inclusion assessment (EcMIA) is simple and reliable,which can provide a new solution for inclusion assessment in aluminum alloy.
其他文献
Objective To establish a comprehensive analytical method based on SPE-UPLC-MS for the simultaneous determination of bisphenol A (BPA), nonylphenol (NP), and oct
In this test, we used phytoplankton assay procedure to carry out determinations of phytoplankton growth potential and limiting nutrients in Gengjing reservoir.T
A two-dimensional numerical model of extratropical storm surge and inundation in Bohai Bay was built based on the unsteady flow Navier-Stokes equations.The mode
Experiments were conducted to study the performance characters of aerobic/anoxic(A/A)digestion of sludge at 30±1℃,while the sludge retention time(SRT)was kept
Dark respiration (non-photorespiratory mitochondrial respiration), which occurs both in the light and in darkness, is vital for growth and survival of algae and
《环境监测管理与技术》坚持"立足江苏,面向全国,服务基层"的办刊宗旨,以创办一流环境监测杂志为目标,紧跟环保工作大局,坚持为科学发展服务,为提高我国环境监测人员业务能力和水平,促进环境监测科学技术发展和创新做出了辛勤努力。
Homeostasis of platelet number in human and other mammals is well maintained for prevention of minor bleeding and for other im-munological functions, but the ex
Surveys were conducted in four seasons in the eastern Beibu Gulf from July 2006 to November 2007, to determine the ichthyoplankton composition, abundance, as we