网学网为需要机械设计的朋友们搜集整理了电火花加工过程中的白层组成，热处理以及裂缝的形成相关资料，希望对各位网友有所帮助!
中文字数:2956,中文页数:4 英文字数:1324页数:3
在本文中，我们要研究常规钢，经淬火后钢以及调质处理后的钢分别在煤油和去离子水电解质溶液中经电解后表面所表现的特征。为了分析加工表面，我们将应用光学显微镜，扫描电子显微镜及X射线衍射。在检测表面裂纹时，我们主要关注白层组成，热处理的工作材料以及被使用的操作参数，如平均放电电流和脉冲的持续时间。目前的结果表明基底材料性能和白层结构对裂缝的形成有着独特的功能。这导致在表面上形成了不同的网络布局裂纹以及在基板上产生了不同的渗透深度。表面裂纹的形成主要是由于冶金阶段中白层的不均等性的增加。它首先出现在表面，然后垂直沿伸到干挠区，最终在些终止。在碳氢化合物为基础的液体介质中利用高脉冲的持续时间和较低的平均放电电流进行加工时，这种裂缝通常出现在表面。在另一方面，穿透性裂缝渗透了整个白层厚度，一直到母质。穿透性裂缝的形成主要由于在凝固过程中收缩形成的重结构延伸到了陨石坑边缘的周边。如果在去离子水和工作材料很脆弱的情况下加工，这种类型的裂缝是很容易形成的。经观察发现裂缝渗透深度与所使用的脉冲能量是成比例的。如果降低脉冲的持续时间，己加工的表面上的裂缝渗透轨道有着一种形成平形裂缝的趋势。
DOI：10.1007/S11663-008-9220-0
矿物，金属和材料学会和ASM国际2009
White Layer Composition, Heat Treatment, and Crack
Formation in Electric Discharge Machining Process
BU¨ LENT EKMEKCI
Characteristics of electric discharge machined (EDM) surfaces of normalized, quenched, and quenched and tempered-treated steels in kerosene and deionized-water dielectric liquids are investigated. Optical microscopy, scanning electron microscopy (SEM) and X-ray diffractometry are employed to analyze the machined surface. Surface cracks are examined in terms of white layer composition, heat treatment of the workpiece material, and operational parameters used, such as average discharge current and pulse-on duration. The present results reveal that base material properties and white layer composition have a distinctive function on crack formation that results in different crack network layouts on the surface and penetration depths in the substrate. Surface cracks, which initiate at the surface, travel down perpendicularly toward the interferential zone, and terminate at this interference, are mainly formed due to an increase in nonhomogeneities of metallurgical phases within the white layer. Such cracks are usually encountered on the surfaces when machining is performed in a hydrocarbon-based dielectric liquid using high pulse-on duration and low average discharge current. On the other hand, penetrating cracks, which penetrate the entire
