本文以30Cr Mn Si A结构钢为研究对象,利用低温等离子体渗氮及低温渗氮-低温氧化复合技术对其进行表面改性研究,重点研究了氧化时间对渗氮30Cr Mn Si A钢表面组织结构和性能的影响。采用扫描电子显微镜、X射线衍射仪分析渗氮层及渗氮-...
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本文以30Cr Mn Si A结构钢为研究对象,利用低温等离子体渗氮及低温渗氮-低温氧化复合技术对其进行表面改性研究,重点研究了氧化时间对渗氮30Cr Mn Si A钢表面组织结构和性能的影响。采用扫描电子显微镜、X射线衍射仪分析渗氮层及渗氮-氧化复合改性层的表面形貌、截面组织和相结构;利用维氏硬度计、摩擦磨损试验机和电化学工作站对渗氮层及复合改性层的硬度、耐磨性和耐蚀性进行评价。结果表明,渗氮层表面主要由ε-Fe_(23)N、γ'-Fe_(4)N和α_N相组成,经不同时间的氧化处理后,渗氮层表面生成Fe_(3)O_(4)相和Fe_(2)O_(3)相;随着氧化时间的延长,氧化物的含量增大,表面硬度增大,最大可达1012 HV_(0.05),改性层的有效硬化层厚度约为200μm;在防腐耐磨方面,渗氮层和渗氮-氧化复合改性层的耐磨性和耐蚀性均显著提高,且短时间氧化的复合改性层具有更好的耐磨性和耐蚀性。
Direct electrodeposition of quarternary Mg-Zn-Li-Ca alloys on a molybdenum electrode from LiCl-KCl-MgCl2-ZnCl2-CaCl2 melts at 943 K was *** voltammograms（CVs） show that the deposition potential of Li shifts in a pos...
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Direct electrodeposition of quarternary Mg-Zn-Li-Ca alloys on a molybdenum electrode from LiCl-KCl-MgCl2-ZnCl2-CaCl2 melts at 943 K was *** voltammograms（CVs） show that the deposition potential of Li shifts in a positive direction after adding MgCl2,ZnCl2 and *** measurements indicate that the codepositon of Mg,Li,Zn,and Ca occurs at current densities lower than-1.55 A/cm2.X-ray diffraction（XRD） indicates that Mg-Zn-Li-Ca alloys with different phases were prepared via galvanostatic *** microstructures of typical phase of Mg-Zn-Li-Ca alloys were characterized by optical microscopy（OM） and scanning electron microscopy（SEM）.The analysis of energy dispersive spectrometry（EDS） shows that elements of Mg and Ca distribute homogeneously in the Mg-Zn-Li-Ca ***,element Zn mainly locates at the edges of the domain.
Mg-5Li-3Al-2Zn-xCe（x=0-2.5;mass fraction,%） alloys were prepared by casting,and heat treatments of homogenization at 300 °C and solid solution at 370 °C were carried *** microstructure and tensile properti...
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Mg-5Li-3Al-2Zn-xCe（x=0-2.5;mass fraction,%） alloys were prepared by casting,and heat treatments of homogenization at 300 °C and solid solution at 370 °C were carried *** microstructure and tensile properties of as-cast alloys and their evolutions after solid solution were *** results show that with the increase of Ce content,Al2Ce/Al3Ce precipitates are formed and the alloys mainly consist of α-Mg,Al2Ce,Al3Ce and AlLi phases,and the amount of AlLi and Al-Ce intermetallics decreases after solid *** content and morphology of the second phases have important effects on the mechanical properties of the alloys;the alloy with 1.0%Ce content exhibits excellent tensile *** tensile strength and elongation of Mg-5Li-3Al-2Zn-0.5Ce alloy is remarkably improved by the solution strengthening effect because of the addition of Ce.
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