TiC添加量对高能激光熔覆Inconel718基陶瓷涂层显微组织和摩擦磨损性能的影响

目的 针对Inconel718镍基高温合金耐磨性不足的问题,制备小尺度TiC增强Inconel718镍基高温合金耐磨复合材料,提升其硬度及耐磨性.方法 利用4000 W高能激光束快速熔融制备TiC/Inconel718基陶瓷复合涂层,并针对TiC质量分数分别为5％、15％、25％的复合涂层,依次进行物相成分、显微组织、压痕硬度、摩擦磨损性能等方面的分析.结果 随着TiC含量的增加,γ-(Ni,Cr,Fe)基体上析出的TiC小尺度颗粒逐渐增多,显微组织明显细化,TiC晶界处偏聚了大量Nb、Mo元素,并与Ti元素置换生成了铌、钼类碳化物.同时,(Nb,Ti)C复合型碳化物和Laves相的析出,进一步提升了复合涂层的显微硬度,由297 HV0.2逐步提升至408 HV0.2,摩擦系数从0.3402降低至0.2628,磨损率从35.15×10–4 g/(N·m)减少至5.96×10–4 g/(N·m),磨损机制由严重的粘着磨损转变为以磨粒磨损和氧化磨损为主.结论 通过高能激光熔覆制备小尺度TiC增强体颗粒,可细化复合涂层的显微组织,其显微硬度随TiC含量的增加而相应提高.在磨损试验过程中,TiC/Inconel718陶瓷复合涂层表现出良好的减摩和耐磨性能.     

铸钢0Cr13Ni5Mo表面电火花沉积YG8涂层的组织和性能

采用新型电火花设备在铸钢表面制备了YG8涂层,采用SEM、XRD技术研究其微观组织和耐磨性能。结果表明:沉积层主要由Co3W3C、Fe3W3C、Fe3Mo3C、WC1 x和Fe7W6C等相组成;沉积层与基体冶金结合,细晶碳化物相弥散分布在沉积层中,能提高沉积层的硬度,平均硬度为1 896.8HV,比基体硬度提高了5倍;沉积层磨损性能是基体的3.4倍,沉积层磨损机理主要是粘着磨损、颗粒磨损和氧化磨损的综合作用;沉积时骤热骤冷过程中形成的细晶粒硬质相是提高沉积层硬度和耐磨性的主要因素。     

WC-Ni-Fe-Mo硬质合金的微观结构与性能研究

本文采用低压烧结的方式制备了性能良好的 WC–Ni–Fe–Mo 硬质合金，研究分析了不同 Mo 添加量对 WC–Ni–Fe硬质合金组织性能的影响。结果表明：不同 Mo 添加量对 WC–Ni–Fe 硬质合金的微观结构与性能有着显著地影响。添加微量的 Mo 可以抑制 WC-Ni-Fe 硬质合金中 WC 晶粒的溶解再析出长大，一定程度上可以细化 WC 晶粒。随着 Mo 在 WC–Ni–Fe 合金中的含量增加，合金孔隙率逐渐下降。密度先下降后升高，而抗弯强度的变化趋势则相反。当 Mo 添加量较少时，合金的硬度较为稳定，抗弯强度明显提升，而断裂韧性逐渐降低；当 Mo 添加量较大时，合金的硬度、抗弯强度降低，而断裂韧性上升。当 Mo 的添加量为0.5 wt %时，合金具有最佳的力学性能，可与同比例 Co 含量的 WC–Co 硬质合金相媲美，其维氏硬度为 HV 1460、抗弯强度为 4245 MPa、断裂韧性为 17.01 MPa·m1/2。     

等离子熔化沉积TiC增强Inconel 718基原位自生复合材料显微组织及高温耐磨性

为改善镍基高温合金Inconel 718的高温耐磨性,利用同轴送粉等离子熔化沉积快速成形技术原位合成了TiC增强Inconel 718高温合金基高温耐磨复合材料。分析了复合材料的显微组织结构和原位自生过程,探讨了增强相TiC的含量对复合材料的显微硬度及高温干滑动摩擦磨损性能的影响规律,研究了复合材料的高温磨损机理。结果表明:复合材料组织细小致密,显微硬度随TiC增强相体积分数增加而相应提高;在高温干滑动磨损实验条件下,复合材料表现出优异的耐磨性。     

铸造碳化钨添加量对镍基复合喷熔涂层性能的影响

在镍基合金粉末NiCrBSi中添加不同比例的铸造碳化钨(WC),并采用氧乙炔火焰喷熔工艺在低碳钢表面制备了相应的Ni基WC复合涂层.采用金相显微镜观察了涂层的显微组织,采用湿砂橡胶轮式磨粒磨损试验机测试了涂层的抗磨粒磨损性能,并采用扫描电镜观察了喷熔粉末和喷熔层磨损后的形貌.结果表明:喷熔层的组织为在NiCr合金基体上弥散分布着不同粒度的碳(硼)化物硬质相;涂层的显微组织和WC的含量对Ni基WC喷熔层的硬度和抗磨损性能影响很大,涂层的硬度和抗磨损性能随WC添加量的增加先增加后减小;当WC的含量为35％时,Ni基体WC喷熔涂层的硬度最高,相应的抗磨粒磨损性能最好.     

直接激光沉积Ti6Al4V/Inconel 718复合材料微观组织与力学性能分析

Ti6Al4V和Inconel 718合金被广泛用于航空航天。但TC4或Inconel 718难以同时满足轻量化和耐高温的需求。本文采用直接激光沉积制备了不同比例Ti6Al4V / Inconel 718复合材料。分别通过X射线衍射,扫描电子显微镜和能谱仪分析相组成,微观结构和元素分布。同时,研究了显微硬度和摩擦磨损性能。研究表明：随着Inconel 718的比例增加,有Ti2Ni和Ni3Ti金属间化合物形成。Ti2Ni的形成机理为：β→α+ Ti2Ni和L→β-Ti+ Ti2Ni,且Ti2Ni金属间化合物的偏析机理为晶间偏析。随着Inconel 718含量增加,复合材料的显微硬度逐渐增加。当Inconel 718的体积分数为50％时,其平均显微硬度值为770 HV,比100％ Ti6Al4V的平均显微硬度高85.5％。显微硬度增加与Ti2Ni金属间化合物的析出强化直接相关。复合材料以磨料磨损为主,并伴随着黏着磨损。随着Inconel 718的增加,黏着磨损减弱。当Inconel 718的体积分数达到达到50％时,磨损量仅为100％ Ti6Al4V的36.9％。     

感应熔覆铁基合金涂层的显微组织与性能

采用感应熔覆技术在奥氏体不锈钢1Cr18Ni9Ti基体上制备了Fe基合金涂层。利用带有能谱仪的场发射扫描电镜(FESEM)分析了熔覆层的显微组织形貌和元素组成,使用X射线衍射仪分析了涂层的物相组成,采用差热分析仪对合金粉末进行了热分析,用显微硬度计和摩擦磨损试验机测试了涂层的显微硬度及干摩擦条件下的滑动磨损性能。结果表明,感应熔覆铁基合金涂层组织致密,内部和界面无孔隙,涂层与基体形成了良好的冶金结合;涂层主要由α-Fe、(Cr,Fe)_7C_3、Cr_7C_3、Ni_3Fe和Fe_3C等组成,且α-Fe中均匀分布颗粒细小的(Cr,Fe)_7C_3、Cr_7C_3析出相;涂层显微硬度约为250HV_(0.1);在不同载荷下,感应熔覆Fe基合金涂层的耐磨损性能均优于1Cr18Ni9Ti基体,涂层磨损机理为典型的层状剥落和粘着磨损。     

直接激光沉积Ti6Al4V/Inconel 718复合材料微观组织与力学性能分析（英文）

Ti6Al4V和Inconel 718合金被广泛用于航空航天。但TC4或Inconel 718难以同时满足轻量化和耐高温的需求。因此采用直接激光沉积制备了不同比例Ti6Al4V/Inconel 718复合材料。分别通过X射线衍射,扫描电子显微镜和能谱仪分析相组成,微观结构和元素分布。同时,研究了显微硬度和摩擦磨损性能。结果表明:随着Inconel 718的比例增加,有Ti_2Ni和Ni_3Ti金属间化合物形成。Ti_2Ni的形成机理为:β→α+Ti_2Ni和L→β-Ti+Ti_2Ni,且Ti_2Ni金属间化合物的偏析机理为晶间偏析。随着Inconel 718含量增加,复合材料的显微硬度逐渐增加。当Inconel718的体积分数为50%时,其平均显微硬度值为7700MPa,比100%Ti6Al4V的平均显微硬度高85.5%。显微硬度增加与Ti_2Ni金属间化合物的析出强化直接相关。复合材料以磨料磨损为主,并伴随着黏着磨损。随着Inconel 718的增加,黏着磨损减弱。当Inconel 718的体积分数达到50%时,磨损量仅为100%Ti6Al4V的36.9%。     

时效处理对WC/Cu-Ni-Mn堆焊层耐磨损性能影响

通过对比未时效与时效后WC/Cu-Ni-Mn堆焊层的微观组织、界面及耐磨损性能,研究时效处理对其耐磨损性能的影响规律,并揭示其耐磨损机理. 结果表明,未时效和时效后的WC/Cu-Ni-Mn涂层相对耐磨损性能分别是时效后Cu-Ni-Mn基体的170.72和210.77倍,时效后涂层耐磨性能提升了23.5%;时效处理后Cu-Ni-Mn金属基中析出了NiMn第二相,基体硬度提升了2.3倍,从而为WC颗粒增强相提供了更稳定支撑;而未时效的Cu-Ni-Mn合金中Ni,Mn原子固溶到Cu晶格,形成了一种α-Cu固溶体;未时效和时效后WC/Cu-Ni-Mn的主要磨损机理均为磨粒磨损和黏着磨损.     

真空熔覆Ni基复合涂层的制备及性能研究

目的 提高65Mn钢的耐磨性和耐酸碱腐蚀性能。方法 通过真空熔覆技术在65Mn钢表面制备了Ni基-碳化钨(WC)复合涂层,并加入稀土氧化铈(CeO₂)改善其微观缺陷。采用扫描电子显微镜(SEM)结合能谱仪(EDS)观察涂层微观结构和元素分布,X射线衍射仪(XRD)测定涂层物相成分,维氏显微硬度计测试涂层硬度。采用带有干涉镜头的摩擦磨损试验机测定涂层的摩擦因数,并通过三维形貌图获取磨痕宽度、深度和体积磨损量,通过磨痕扫描形貌分析摩擦磨损机理。采用电化学工作站分别测试涂层在酸性和碱性腐蚀介质中的电化学性能。结果 涂层以(Ni,Cr,Fe)固溶体、WC及含W增强相的Cr4Ni15W和Ni17W3作为主要的强化相组成。涂层随硬质相WC含量的增加而出现孔洞、裂纹等缺陷,在CeO₂的改善作用下,质量分数为30%的WC硬质相涂层组织致密,无明显缺陷,平均显微硬度达900HV1～1 000HV1,是基体硬度的3～4倍;摩擦磨损性能较65Mn钢基体有明显提高,在不同试验条件下,其体积磨损率仅为65Mn钢基体的13.1%～17.4%,但摩擦因数略高于基体。磨痕分...     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.