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氮离子注入硅表面的力学性能及其微摩擦磨损行为研究 总被引:2,自引:2,他引:2
以单晶硅作为研究对象,选用离子注入剂量分别为5 ×1014 ions/cm2、6 ×1015ions/cm2和1 ×1017ions/cm2,注入能量为110 keV的氮离子注入单晶硅片,利用原位纳米力学测试系统对氮离子注入前后单晶硅片的硬度和弹性模量进行测定,在UMT-2型微摩擦磨损试验机上对氮离子注入前后单晶硅片的往复滑动微摩擦磨损性能进行研究.结果表明,氮离子注入后单晶硅片的纳米硬度和弹性模量减小,且注入剂量越大,其降低越明显.氮离子注入后单晶硅片的减摩性能提高,其摩擦系数大幅度降低,在载荷达到一定值后,氮离子注入层被迅速磨穿,摩擦系数迅速增加并产生磨痕.其磨损机制在小载荷下以粘着磨损为主,在大载荷下以材料的微疲劳和微断裂为主. 相似文献
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采用离子注入技术对Cr2O3涂层表面进行氮离子注入处理,用俄歇电子能谱仪、微区X射线衍射仪及X射线光电子能谱仪分析氮离子注入改性层的相组成及其氮元素沿层深的浓度分布,用销-盘式摩擦磨损试验机考察了注入前后Cr2O3涂层的磨损性能,用扫描电子显微镜观察其磨痕表面形貌及摩擦界面间的物质转移.结果表明,氮离子注入后Cr2O3涂层的显微硬度有所提高,表面残余压应力增加,表面粗糙度降低,在注入层内形成大量细小弥散分布的硬质析出相CrN和β-Cr2N等,从而提高了Cr2O3涂层材料的磨损性能. 相似文献
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氮及钛等离子体基离子注入铝合金表面改性层的摩擦磨损性能研究 总被引:7,自引:2,他引:5
研究了铝合金LY12等离子体基氮及钛离子注入层的摩擦磨损性能。用X射线光电子能谱和小掠射角X射线衍射对改性层中各元素分布及相组成进行了分析。用扫描电子显微镜对注入层形貌进行了观察和分析。结果表明:注入层由TiN、α-Ti、AlN、Al2O3和TiO2等相组成;注入后试样硬度提高了1倍以上;在低载荷下,摩擦系数处于0.10-0.14之间,注入层寿命提高了12倍以上,耐磨性提高了100倍以上;随着滑动载中增加,摩擦系数有所增大,而磨性有所降低;在注入层被磨穿以前以剥层磨损为主并伴有轻微的划伤,在注入层被磨穿以后以粘着磨损为主并伴有犁沟和粘着转移。注入改性层具有适当的梯度结构是提高铝事金表面硬度和耐磨性的主要原因。 相似文献
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在不同温度下对6061铝合金分别进行了氮、氧等离子体浸没离子注入处理,氮与氢混合气体等离子体浸没离子注入处理,以及在氮气氛中的钛或铝等离子体浸没离子注入与沉积处理;采用X射线光电子能谱仪分析了注入改性层的相组成、高温下氧离子注入层的成分及注入离子浓度的深度分布;同时测定了注入改性层的显微硬度及摩擦磨损性能.结果表明:经300℃下氧离子注入处理后铝合金表面形成了较厚的硬质Al2O3层,从而使铝合金表面的耐磨寿命显著延长;经氮/氢混合注入以及氮气氛中金属离子注入和沉积处理后的铝合金表面的抗磨性能显著改善;同单一氮离子注入相比,氮/氢混合注入能更有效地改善铝合金的性能. 相似文献
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YL12铝合金铁离子注入层的摩擦学特性研究 总被引:1,自引:1,他引:0
对 YL12铝合金进行了铁离子注入 ,用俄歇电子能谱 (AES)分析了注入层剖面元素分布 ,同时考察了注入层的表面显微硬度、脆性和在干摩擦条件下的摩擦磨损特性 .采用扫描电子显微镜 (SEM)对磨痕表面形貌进行了观察分析 .研究结果表明 :铁离子在注入层中沿剖面呈高斯分布 ;注入层表面显微硬度有所增加 ,摩擦系数显著降低 ;当注入剂量为 7× 10 1 6 Fe / cm2 时 ,注入试样的耐磨性为未注入试样的 3 80 0倍 ;随着铁离子注入剂量的增大试样的表面脆性增加 ,耐磨性降低 ;注入前材料的磨损机制以粘着磨损和磨粒磨损为主 ,注入后磨损机制则以氧化磨损为主 相似文献
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W6Mo5Cr4V2钢氮离子注入表面改性层的摩擦学性能 总被引:6,自引:0,他引:6
对 W6 Mo5 Cr4V2钢进行氮离子注入 ,用销 -盘式摩擦磨损试验机考察了钢表面注入改性层的摩擦磨损性能 ;用扫描电子显微镜、俄歇电子能谱仪及微区 X射线衍射仪等考察了改性层的相组成、氮元素沿注入层深度方向的浓度分布及磨损机理 .结果表明 ,离子注入处理后钢表面显微硬度提高、残余压应力增大、表面粗糙度降、注入层中形成了大量细小弥散分布的硬质析出相ε- Fe2 - 3 N、Cr N及β- Cr2 N等 ,从而改善了材料的摩擦学性能 ,并导致磨损机理发生变化 .正交试验结果表明 ,氮离子注入对 W6 Mo5 Cr4V2钢摩擦学性能的改善程度与注入能量和注入剂量不成正比 ,注入参数存在最佳值 ,最佳注入能量为 10 0 ke V,注入剂量为 4× 10 1 7ions/cm 相似文献
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离子注入超高分子量聚乙烯的摩擦磨损性能研究 总被引:10,自引:5,他引:10
对人工关节软骨材料——超高分子量聚乙烯(UHMWPE)进行O+和C+离子注入改性,采用销-盘式摩擦磨损试验机考察了离子注入UHMWPE试样在血浆润滑条件下同Si3N4陶瓷球对摩时的摩擦磨损性能;用扫描电子显微镜观察分析了注入和未注入试样及其磨痕表面形貌,用红外光谱仪(IR)分析了注入和未注入试样的化学特征.结果表明:经O+和C+离子注入处理的UHMWPE试样表面发生了碳化并形成了类金刚石结构;O+和C+注入处理均有利于增强UHMWPE的耐磨性能,而O+离子注入试样的耐磨性能优于C+离子注入试样,经450keV、5×1015/cm2的O+离子注入试样的耐磨性能最佳;未注入UHMWPE试样在血浆润滑条件下同陶瓷对摩时主要呈现粘着、塑性变形和犁沟特征,而注入UHMWPE试样在相同条件下主要呈现表面硬化层疲劳裂纹萌生、扩展、剥落及磨粒磨损特征. 相似文献
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对《力学》中的物体自由度进行多方面分析,以深化教学、提高学生正
确分析物理问题的能力.使用实际教学分析的研究方法,在《力学》范围内讨论自由度与坐标、
自由与约束的关系并得以下结论:
(1) 同一物体的自由度随其所在的``空间'不同而不同, 不因坐标系的选取不同而
异, 在同类参考系中不因参考系的动静而有别;(2)自由度遵循叠加原理.
讨论了质点系的总自由度及相关计算问题,并指出研究《力学》中自由度的意义. 相似文献
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Tibor Javor 《Experimental Mechanics》1968,8(4):171-176
The present paper deals with development and design of new methods utilizing Wiedemann's effect for determination of state of strain in building structures. Wiedemann's effect and some features of torsional strain of magnetic field are the basis of new experimental method. Especially the point electromagnetic strain gages using the effect of pure torsion of electromagnetic field to enable universal examination. For strain-gage measurements, almost all physical quantities are used which can be related to the variation in length of the structures. From the electric strain measurements, the most commonly used methods are the measurements by resonance-wire strain gages or by electric-resistance strain gages. In this paper, electromagnetic strain gages are discussed using the Wiedemann effect, and the author describes some new measuring equipment and his own suggestions and methods based on an application of this effect. 相似文献
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I. M. Ametov 《Fluid Dynamics》1975,10(3):429-433
The exact solutions of the nonlinear equations of filtration of an aerated liquid have been obtained in [1–3]. In [4] the system of equations of an aerated liquid have been reduced to the heat-conduction equation under certain assumptions. An approximate method of computing the nonsteady flow of an aerated liquid is given in [5], where the real flow pattern is replaced by a computational scheme of successive change of stationary states. In [6] the same problem is solved by the method of averaging. In the present article estimates of the solution of the equations for nonstationary filtration of an aerated liquid in one-dimensional layer are constructed under certain conditions imposed on the desired functions. These estimates can be used as approximate solutions with known error or for the verification of the accuracy of different approximate methods. We note that the use of comparison theorem for the estimate of solutions of equations of nonlinear filtration is discussed in [7–9]. The methods of constructing estimates of solutions of various problems of heat conduction are given in [10, 11] 相似文献
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It is well known that the problem on nonseparating potential flow of an incompressible fluid about an array of profiles reduces to an integral equation for a certain real function, determined on the contours of the profiles of the array. As such a function one can take, as was done, for instance, in [1–5], the relative velocity of the fluid on the profiles of the array. For arrays of profiles of arbitrary shape it is necessary to solve the corresponding integral equation numerically. In the particular examples of the calculation of aerodynamic arrays that are available [1–3] the numerical methods used were based on the approximate evaluation of contour integrals by rectangle formulas. As investigations showed, sizeable errors arose thereby in the approximate solution obtained, these being especially significant in the case of curved profiles of relatively small bulk. In the present paper a method for the numerical solution of the integral equation obtained in [5] is proposed. The method is based on the replacement of a profile of the array with an inscribed N polygon, the length of whose sides is of the order N–1 and whose internal angles are close to . Convergence with increasing N of the numerical solution to an exact solution of the integral equations at the reference points is demonstrated. Examples of the calculation are given.Novosibirsk. Translated from Izvestiya Akademii Nauk SSSR. Mekhanika Zhidkosti i Gaza, No. 2, pp. 105–112, March–April, 1972. 相似文献