ZA—27合金摩擦磨损性能的研究

进行了ＺＡ－２７合金与牌号为ＱＳｎ６．５－０．１锡青铜合金摩擦磨损性能的对比实验。实验结果表明，在低速度重载润滑条件下，ＺＡ－２７合金的减摩能力和抗磨损明显优于ＱＳｎ６．５－０．１合金，ＺＡ－２７合金代替ＱＳｎ６．５－０．１合金制造纺机上纱锭轴承底座提供了实验依据。     

耐磨合金堆焊焊条研究

对高碳Ｗ１２Ｍｏ６Ｖ３Ｃｒ２合金系统的合金焊条进行试制研究,发现当合理调整焊条化学成分时,能时缝金属具有隐晶马氏体、残余奥氏体、碳化物组织,其组织晶粒细化,加之,焊条采用碱性渣系和适当地过渡钒在焊缝金属中的含量,从而大大地提高了焊条的工艺性能和焊缝金属的抗裂性能。     

阀门密封面高温耐磨堆焊合金的研究

通过研制５２号合金与１３７号金常温和高温硬度对比测试以及金相组合的对比分析，证明了５２号合金是比较理想的作为阀门密封面高温耐磨堆堆焊的合金材料，用它来代替目前遍使用的钴铬钨贵重合金，具有较高的经济效益。     

影响镶铸截齿工作性能的因素

截齿是采煤机工作时的重要零部件,它不但要有高的耐磨性,而且要有很高的抗冲击性能.镶铸复合金属材料截齿是将铬系耐磨合金与抗冲击性能好的低合金钢利用镶铸工艺一次浇铸成型,两金属复合界面在高温液态金属作用下形成冶金结合层,铬系耐磨合金与低合金钢组成的镶铸复合金属材料截齿在工作时两金属不分离,从而提高镶铸复合金属材料截齿的使用寿命.     

装饰合金的研究

本文通过正交试验设计了最佳的合金成分,并简要介绍了合金的生产工艺。试验结果明表,该合金具有优良的加工性能,良好的耐蚀性,其表面呈现与18开金相似的金黄色泽。合金初步应用于生产证明,它的综合性能是比较好的,并可以获得良好的经济效益。     

铬硼及硬质相形态在高温耐磨堆焊合金中作用

通过高温硬度、高温磨损试验，系统地研究了合金元素铬、硼对Ｃｒ－Ｂ－Ｗ－Ｖ系高温耐磨料磨损等离子弧堆焊合金的红硬性影响规律．硬质相Ｃｒ７Ｃ３条束轴向垂直于磨损面时，堆焊合金的耐磨性最好．     

钾盐熔剂对Al-Pb-Cu合金的作用

用不同实验方法研究钾盐熔剂对合金的作用及其机理。该熔剂能在一定条件下析出钾元素,致使合金表面张力降低并有效地防止铅偏析;可减少渣量和合金中的含氢量;还能使合金产生多孔结构,从而提高减摩性能而不降低强度和韧性。实践证明,使用该钾盐不需精炼即可获得优质铸件。     

耐磨Zn-Al合金的老化原因分析

对多种成分的铸造合金的加速腐蚀实验、电化学检测、金相分析、X射线衍射和电子探针分析,证实了各种成分的合金都发生晶界腐蚀;随着铝含量的增加,由晶界富铝相腐蚀逐渐过渡到晶界富锌相腐蚀;晶界腐蚀是Zn-Al合金老化的主要原因。在此基础上,提出了改进Zn-Al合金耐腐蚀性能的几种可能途径:适当提高铝含量,表面处理,加入合金元素等。     

无铬镍不锈钢力学性能与成分的关系

目的研究Ｆｅ－Ｍｎ－Ａｌ－Ｃ合金中元素含量对合金室温拉伸性能的影响．方法采用归纳法分析大量文献报导的实验数据．结果提出一个与Ｆｅ－Ｍｎ－Ａｌ－Ｃ合金中Ｍｎ,Ａｌ,Ｃ含量有关的函数χ,找到了合金室温力学性能随χ变化的经验公式．结论本研究得到的合金拉伸性能与合金元素含量之间的解析函数关系对研究与设计一种由Ｍｎ,Ａｌ取代传统不锈钢中的Ｎｉ,Ｃｒ的新型不锈钢具有重要意义．     

2.0B对微晶高速钢磨损性能的影响

对微晶Ｍ２＋２．０Ｂ的耐磨性能及与之相关的机械性能进行了研究,并与对比材料－普通Ｍ２进行比较,分析了两种材料性能差异的原因;认为高硬度介稳态组织的抗磨损性能低于稳定态组织,为提高耐磨性应适当降低硼含量。     

Multi-objective robust design optimization of a novel negative Poisson’s ratio bumper system

Negative Poisson’s ratio (NPR) structure has outstanding performances in lightweight and energy absorption, and it can be widely applied in automotive industries. By combining the front anti-collision beam, crash box and NPR structure, a novel NPR bumper system for improving the crashworthiness is first proposed in the work. The performances of the NPR bumper system are detailed studied by comparing to traditional bumper system and aluminum foam filled bumper system. To achieve the rapid design while considering perturbation induced by parameter uncertainties, a multi-objective robust design optimization method of the NPR bumper system is also proposed. The parametric model of the bumper system is constructed by combining the full parametric model of the traditional bumper system and the parametric model of the NPR structure. Optimal Latin hypercube sampling technique and dual response surface method are combined to construct the surrogate models. The multi-objective robust optimization results of the NPR bumper system are then obtained by applying the multi-objective particle swarm optimization algorithm and six sigma criteria. The results yielded from the optimizations indicate that the energy absorption capacity is improved significantly by the NPR bumper system and its performances are further optimized efficiently by the multi-objective robust design optimization method.     

RP型中速磨煤机辊套用耐磨新材质——V、Ti、B合金化Cr20Mo2铸铁的研究

本文在分析RP型中速磨煤机辊套的工况及磨损机理的基础上,设计了用于辊套的新材质.通过对新材质的组织、力学性能、热处理工艺及抗磨料磨损性能的试验研究发现:V、Ti、B等元素的加入,细化了组织,改善了碳化物的形态和分布,材质在保持高硬度的基础上,改善了冲击韧性,表现出优良的抗磨料磨损能力。     

液力减速器叶片前倾角度三维集成优化

为了对液力减速器叶片前倾角度进行参数优化,建立了液力减速器叶栅参数三维集成优化仿真平台。以叶片倾角为设计变量,三维CFD分析作为求解器进行试验设计,并根据试验样本结果构建响应面法模型(RSM)进行优化,得到一套最优的动、定轮叶片倾角参数。就叶片倾角参数对液力减速器内流场特性、制动外特性的影响进行了分析,并结合试验数据对优化前后制动性能进行了对比。结果表明,优化仿真平台精度较高,结果可信。优化后的液力减速器制动性能显著提高。     

考虑铆钉位置不确定性的异种轻质金属铆接接头疲劳寿命优化

针对铆钉位置坐标对铆接接头疲劳寿命的影响问题,采用单行替换法来实现了铆接接头的寿命优化。首先,对铝合金自冲铆接接头进行单调拉伸和疲劳试验研究,通过试验数据拟合获得S-N曲线。然后,建立自冲铆接结构的有限元模型,通过Abaqus进行循环载荷作用下的铆接接头力学分析,研究了铆接点位置对铆接接头力学性能的影响。最后,将铆接点的坐标作为设计变量,铆接结构疲劳寿命为优化目标,基于单行替换法进行全局寻优,获得了铆接接头最大疲劳寿命时的位置坐标,为技术人员开展铆接接头设计提供了参考依据。     

Design Optimization of CFRP Stacking Sequence Using a Multi-Island Genetic Algorithms Under Low-velocity Impact Loads

A method to improve the low-velocity impact performance of composite laminate is proposed, and a multi-island genetic algorithm is used for the optimization of composite laminate stacking sequence under low-velocity impact loads based on a 2D dynamic impact finite element analysis. Low-velocity impact tests and compression-after impact(CAI) tests have been conducted to verify the effectiveness of optimization method. Experimental results show that the impact damage areas of the optimized laminate have been reduced by 42.1% compared to the baseline specimen, and the residual compression strength has been increased by 10.79%, from baseline specimen 156.97 MPa to optimized 173.91 MPa. The tests result shows that optimization method can effectively enhance the impact performances of the laminate.     

Composition demixing effect on cathodic arc ion plating

1. IntroductionCathodic arc ion plating (CAIP) has been acceptedas an effectual physical vapor deposition (PVD) tech-nology for surface coating. This deposition technologyhas many advantages, such as high film density, highfilm adhesion, low substrate tem…     

Efficient aero-structural design optimization: Coupling based on reverse iteration of structural model

Traditional coupled multi-disciplinary design optimization based on computational fluid dynamics/computational structure dynamics(CFD/CSD)aims to optimize the jig shape of aircraft,and general multi-disciplinary design optimization methodology is adopted.No special consideration is given to the aircraft itself during the optimization.The main drawback of these methodologies is the huge expanse and the low efficiency.To solve this problem,we put forward to optimize the cruise shape directly based on the fact that the cruise shape can be transformed into jig shape,and a methodology named reverse iteration of structural model(RISM)is proposed to get the aero-structural performance of cruise shape.The main advantage of RISM is that the efficiency can be improved by at least four times compared with loosely-coupled aeroelastic analysis and it maintains almost the same fidelity of loosely-coupled aeroelastic analysis.An optimization framework based on RISM is proposed.The aerodynamic and structural performances can be optimized simultaneously in this framework,so it may lead to the true optimal solution.The aerodynamic performance was predicted by N-S solver in this paper.Test shows that RISM predicts the aerodynamic and structural performances very well.A wing-body configuration was optimized by the proposed optimization framework.The drag and weight of the aircraft are decreased after optimization,which shows the effectiveness of the proposed framework.     

沥青混合料目标配合比级配优选的灰度模型评价法

沥青混合料目标配合比级配组成设计时有多种选择,存在如何获得最优级配的问题,这关乎配合比设计的质量,直接影响铺面质量和路面的服役寿命,为此需要一种科学方法进行级配优选。基于优选理论,分析混合料性能指标特征,构建非定量指标、常规定量指标及路用性能指标3层次优选指标体系;设计3组典型级配,开展典型性能试验和分析,得到各评价指标值;采用德尔斐专家调查法进行隶属度、盲度分析和总体认识度指标赋权;采用灰度模型理论,对评价指标进行归一化处理,对各指标进行关联度分析,逐级对灰度模型体系进行综合评价和排序,根据排序结果最终选出最优的目标配合比级配。研究中,提出了灰度模型分析法的指标体系和流程,并讨论了方法中分辨系数的取值对优选结果的影响。结果表明:该方法可系统全面分析级配组成对应的性能指标体系,可筛选出符合路用性能指标的最优特征,可为沥青混合料目标配合比设计的级配优选提供一种有效技术方法。     

高效低烟尘结构钢焊条的优化设计

采用正交优化设计的方法实现了对低烟尘结构钢焊条药皮配方的优化设计.通过对试验结果的直观和方差分析，建立焊条烟尘量与焊条药皮组分含量之间的线性回归方程，对目标函数求极值，从而获得合金的最优配方.焊条药皮中还加入了适量的铁粉，提高了焊条的熔覆速率.通过实验验证，所研制的低烟尘结构钢焊条的各项工艺性能良好，烟尘量降低到4.12 g/kg.焊缝熔覆金属的机械性能达到GB/T5117-1995标准.     

基于性能预测的主油泵优化设计

主油泵是汽轮机组的供油系统中重要设备之一。对这类主油泵研制若采用传统以模型试验为主的研究开发过程,不仅成本高和周期长,而且对其流体动力性能的优化并不十分有效。本文介绍采用以全流道三维粘性流场数值模拟为基础进行性能预测的优化设计方法,通过数值试验取代传统模型试验来实现主油泵的优化设计技术。通过对引进的600MW汽轮机组配套的主油泵进行全流道三维流场数值模拟及性能预测,并与试验结果进行对比分析,验证了基于多工况流场数值模拟的性能预测技术的可靠性。结合国内大型汽轮机组配套的主油泵优化和自主创新工程需要,以某300MW汽轮机组配套的主油泵改造为具体对象进行优化设计,使其性能得到了很大的提高,进一步证明文中提出方法的可行性和可靠性。