共查询到20条相似文献,搜索用时 125 毫秒
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激光加工微凹坑表面对缸套-活塞环摩擦性能的影响 总被引:1,自引:0,他引:1
研究了激光加工微凹坑对缸套-活塞环摩擦特性的影响,通过改变激光微凹坑参数,加工出具有不同微凹坑表面形貌的缸套试件,并对表面形貌进行了测量和表征,基于台架试验获取了试验过程中的缸套-活塞环间的摩擦力、温度和缸套磨损量等参数.将试验结果与表面形貌表征结果结合,研究表面形貌参数与摩擦学特性的关系.定量分析了三维表面形貌参数Sa、Sp、Sv、Vmp、Vmc、Vvv和Spc与摩擦学特性的关系,并给出了可以改善摩擦学特性的参数最佳范围,为表面形貌优化设计提供了依据. 相似文献
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简要介绍了激光表面强化技术及其机理,利用激光技术对大功率机车柴油机的气缸套、活塞环槽进行激光硬化处理技术的试验研究,经硬化处理的气缸套、活塞已装车试验考核. 相似文献
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采用常压等离子束对气缸套进行合金化处理。结果是:当气缸套表面熔化时,溶凝区有合金元素的溶入和注入,但严重影响缸套的表面质量;若缸套表面不熔,则合金元素扩散渗入固态缸套表面的可能性极小,硬化效果的本质是等离子束淬火。 相似文献
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表面变质处理在过去的20年间由于不断研究新工艺而迅速发展,在微电子工业中应用广泛,获得了良好的经济效益。表面变质处理技术就是改变现有表面的机械性能或组成,即镀敷薄膜或涂层,敷着不同材料以形成新的表面。表面变质处理通常包括表面处理。表面处理又包括机械处理,如喷丸处理(可硬化表面);热处理,如激光或电子束加热,通过固溶体中的硬化成分硬化该表面;扩散处理,如渗碳、渗氮,它可改善表面组成;化学处理,如浸蚀或氧化,通过化学反应改变表面成分;离子注入,把离子加速达高能后注入近表层,从而改变表面组成。镀敷技术包括传统的电 相似文献
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激光微珩磨缸套润滑耐磨性能理论分析 总被引:9,自引:0,他引:9
基于摩擦学理论和缸套/活塞环的润滑磨损特征,采用激光微造型技术,在缸套内表面进行规则微观几何形貌的造型。通过分析缸套/活塞环摩擦副的物理模型,建立了具有规则微观几何形貌特征的缸套内表面润滑理论模型,用变异的多重网格法进行了数值求解,并对微观几何形貌参数进行了初步的优化设计。研究结果表明,即使在两个平面摩擦副上进行简单的激光微凹腔造型,也能维持良好的动压润滑效果。同时得出,微凹腔的面积占有率为15%、深径比为0.5时,润滑油膜厚度增加了10%-15%,平均摩擦力减小了20%,润滑减磨效果较好。 相似文献
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分析研究活塞顶环槽激光硬化层的组织,硬度分布和耐磨性。试验表明,采用激光表面硬化的方法能提高柴油机活塞顶环槽的耐磨性,而且比经原镀铬工艺处理环槽的耐磨性有较大的提高。 相似文献
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论述了柴油机气缸套表面强化处理问题,包括盐浴氮化强化、激光淬火强化、珩磨处理等;分析了相关的金相、硬度问题;还介绍了磨损试验和装车考核结果及结论性意见。 相似文献
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《International Journal of Pressure Vessels and Piping》2003,80(1):41-48
A study of progressive inelastic deformation under a moving temperature distribution was carried out for a 316L stainless steel cylinder by a structural test and corresponding analysis. This structural test intends to simulate the thermal ratchetting behavior occurring at the thermal liner of a liquid metal reactor as a free surface of a hot sodium pool moves up and down under plant heat-up, cool down conditions and other thermal transients. The thermal ratchetting load of heating the test cylinder up to 550 °C was applied nine times and deformation was measured with one laser displacement sensor and two LVDTs. The temperature distribution of the test cylinder in the axial direction was measured and this was used for the ratchetting analysis. The thermal ratchet deformations were analyzed with the constitutive equation of the non-linear combined hardening model, which was implemented into ABAQUS by means of a UMAT subroutine and the analysis results were compared with those of the test. The residual displacement after nine cycles of the thermal load was measured to be 1.79 mm. The ratchetting deformations obtained by the analysis with the combined hardening model were in reasonable agreement with those of the structural tests. In addition, a case study of the effect of variations of load conditions and geometry conditions on the thermal ratchet was carried out. 相似文献
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阐述了采用激光珩磨技术加工理想平台网纹缸套的可行性、一致性,以及激光珩磨网纹缸套在CA6DF2柴油机上的试验情况,机油耗对比试验及额定功率试验表明,与传统平台珩磨网纹缸套相比,采用激光珩磨网纹缸套能显著降低发动机机油燃油比和漏气量。 相似文献
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针对激光硬化技术在船用二冲程发动机活塞头上的应用展开研究。介绍激光硬化活塞头实施前的准备及实施中的注意事项。经实船验证,采用激光硬化技术可大大提高活塞头的应用寿命。 相似文献
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燃气轮机零部件"火焰筒"陶瓷烘干以后需要在1180±10℃的烧结炉内进行烧结工序,火焰筒上除了两个直径35 mm的圆孔及底部的扇形孔内壁20 mm内没有陶瓷涂层外,其他位置均涂有W-200高温陶瓷涂层,没有涂层的区域为被保护区域,可以直接与工装接触,传统工装采用一个活动销、一个固定销结构,该结构可以有效固定"火焰筒",但是工件拆装不便,工装移动时工件发生摆动,难以保证不与陶瓷涂层接触。结合之前情况对工装结构和材料进行改进,通过软件三维仿真和高温试验,成功研制出一种新的工装,有效解决了不破坏陶瓷涂层,方便工件装卸,移动时稳定性好等问题。 相似文献
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《International Journal of Heat and Mass Transfer》2007,50(23-24):4600-4606
An exact solution was developed for a quasi-steady-moving-interface heat transfer problem in laser transformation hardening by a beam customized to a flat-top rectangular shape. The absorption and release of the latent heat were taken into account. The solution provided the body temperature, heating rate, and subsequent cooling rate. Using the IT and CCT diagrams, the rapid austenitization and pearlitic/martensitic phase transformation were determined for prediction of the hardening effect. In the experimental study, a diffractive optical kinoform (DOK) was used to customize a conventional Gaussian laser spot beam to a flat-top rectangular beam. A reasonable agreement between the theoretical predictions and the experimental measurements was obtained. 相似文献
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An analytical model is presented that describes the bending process following the absorption of a Gaussian laser pulse by the surface of a moderately thick metal plate. The model is based on the constitutive equations of thermoelastoplasticity and therefore fundamentally describes this optodynamic process. Assuming relatively short laser pulses, Green's function is used as an approximation for the real plate temperature. The plate is assumed to be made of elastic, linearly hardening material. 相似文献