偏压对电弧离子沉积锆膜性能的影响

为研究偏压对通过电弧离子沉积法沉积的锆膜性能的影响,并探究锆膜在不同存储条件下的氧化程度,通过调整沉积过程偏压的大小以及占空比制备多组试样,利用扫描电子显微镜、X射线测厚仪、X射线衍射仪以及纳米划痕仪对薄膜的表面形貌、沉积速率、薄膜结构、膜基结合力进行了研究。并利用X射线光电子能谱测试了锆膜在不同存储状态下的氧化程度。结果表明,偏压的增大会提升膜层表面光洁度。但因高能粒子反溅射作用的增强,会降低薄膜的沉积速率。同时,膜基结合力随着偏压的增大有升高的趋势,且膜层的(100)晶面择优趋势会逐渐减小。另外,偏压占空比的增加也会导致沉积速率下降。锆膜表面的氧化层厚度随着时长会逐渐增大,且膜层在大气中暴露一天的氧化程度比真空存储(10^-5 Pa)半年严重。     

Cr及Cr-Ni掺杂对不同偏压下TiAlN薄膜性能的影响

为了使4Cr13不锈钢表面性能得到更好的优化和获得镀膜最佳的偏压工艺,在不同的偏压工艺下,采用多弧离子镀技术和磁控溅射技术在4Cr13不锈钢表面沉积掺杂Cr和同时掺杂Cr、Ni的TiAlN薄膜.采用附着力自动划痕仪研究不同偏压条件下薄膜与基体的结合力,采用扫描电子显微镜观察和分析薄膜的表面形貌,采用XRD技术检测薄膜的相结构,采用显微硬度计测量薄膜的显微硬度.结果表明:适当的偏压可以提高薄膜的硬度和结合力,在偏压为-250 V时,薄膜的表面硬度达到最大值2 259 HV0.1 N,结合力为36 N;并且掺杂Ni元素能够起到增强膜基结合力的效果.     

偏压对阴极电弧离子镀AIN薄膜的影响

在不同基体负偏压作用下,用阴极电弧离子镀等离子体物理气相沉积（PVD）方法在单晶Si(100）基片上获得六方晶系的晶态AIN薄膜。用X射线衍射仪分析了沉积膜的物相组成和晶格位向随偏压的变化。在扫描电子显微镜（SEM）下观察沉积膜的显微组织形貌。结果表明,在较小偏压下,AIN膜呈（002）择优取向,表面致密均匀;在较大偏压下,AIN膜呈（100）择优取向,表面形貌则粗糙不平,AIN薄膜的择优取向及表面形貌受到不同偏压下不同离子轰击能量的影响。     

基体偏压对中频磁控溅射沉积DLC膜结构的影响

利用中频非平衡磁控溅射技术,以氩气和甲烷混合气体为工作气体,在载玻片和单品硅片上沉积含氢的类金刚石簿膜.改变加载在基体上的负偏压,在0～400 V范围内,制备5种偏压值下的薄膜,研究偏压对薄膜结构的影响.用光学显微镜和AFM考察薄膜的光学形貌;激光Raman谱定性分析膜的化学组分;VFIR分析其C-H键合类型;纳米压痕法测量膜的硬度.结果表明:当基体上施加偏压-100 V时,可以有效地提高沉积粒子与基体结合力以及溥膜的致密性,薄膜中正四面体的sp3结构和sp3CHn含最增加,纳米硬度提高.     

工艺参数对阴极电弧离子镀ZrN薄膜表面形貌及结构的影响

本文采用阴极电弧离子镀技术制备了ZrN膜层,研究了工作气压、偏压、弧流等工艺参数对ZrN膜层表面形貌和结构的影响,分别用扫描电镜(SEM)、X射线衍射仪(XRD)分析了膜层的表面形貌及相结构。结果表明:工作气压、偏压、弧电流等工艺参数对ZrN膜层的表面形貌有较大的影响,在本实验内适当提高N2压强、偏压以及在稳弧前提下降低弧流有利于减少大颗粒,改善ZrN膜层表面形貌,提高膜层综合性能;不同工艺参数下制备的ZrN膜层均具有典型的面心立方结构,工作气压和弧电流对ZrN膜层晶体生长方向的影响较小,偏压对晶体生长方向的影响显著,在20 V偏压下,晶体呈(200)面择优取向,继续提高偏压(100 V~300 V),晶体生长呈(111)面择优取向。     

磁场增强的碳阴极弧沉积ta-C薄膜的基体偏压效应

利用磁场增强的石墨阴极弧在Si片和M2高速钢上沉积了ta-C薄膜,重点研究了基体偏压对膜层截面形貌、沉积速率、膜层结构、耐腐蚀性能和摩擦系数的影响。结果发现,在-100V偏压下膜层较为致密,缺陷较少;基体偏压增加,膜层沉积速率增加;拉曼光谱分析显示,在-100V偏压下ID/IG值最小(0.4),表明sp3键含量最高;平衡腐蚀电位随基体偏压先升高后降低,在-100V时最大;膜层耐蚀性提高3倍;摩擦副采用Al2O3,在-100V偏压下摩擦系数最低。     

多弧离子镀(Ti,Al,Zr,Cr)N多组元氮化物膜的研究

采用多弧离子镀技术,使用Ti Al Zr合金靶和Cr靶,在W18Cr4V高速钢基体上沉积(Ti,Al,Zr,Cr)N多组元氮化物膜.利用扫描电镜(SEM)、电子能谱仪(EDS)和X射线衍射(XRD)对薄膜的成分、结构和微观组织进行测量和表征;利用划痕仪、显微硬度计测评薄膜的力学性能.结果表明,获得的多组元氮化物膜仍具有B1 NaCl型的TiN面心立方结构;薄膜的成分除-50V偏压外,其它偏压下的变化均不明显;增大偏压可减少薄膜表面的液滴污染,提高薄膜的显微硬度及膜/基结合力,最高值可分别达到HV3300和190N.     

基底负偏压对直流磁控溅射CrN薄膜择优取向及表面形貌的影响

直流磁控溅射法制备不同基底负偏压下的CrN薄膜,采用XRD分析薄膜相结构,EDS分析薄膜表面成分,SEM观察薄膜表面形貌,并对偏压作用机制进行了探讨。结果表明,当Ar流量6ml/min、N2流量30ml/min时,在基底负偏压增大过程中,CrN薄膜始终由CrN相组成,但薄膜生长发生了(111)(-50V)向(200)(-125V)再向无明显择优生长(-225V)的转变。低偏压时,CrN薄膜[111]向[200]取向转变主要是轰击表面氮离子浓度增加导致;高偏压时,薄膜中Ar浓度大幅增长,高能离子长时间轰击破坏晶粒取向性,使薄膜呈无择优取向。同时,负偏压增加使薄膜表面形貌从具有棱角的不规则形状逐渐变为粒状结构,且晶粒逐渐细小。     

偏压方式对金刚石薄膜生长的影响研究

采用脉冲偏压和直流偏压辅助热丝化学气相沉积装置在硅片表面制备了金刚石薄膜,对比研究了两种方式施加的偏压大小对薄膜表面形貌以及质量的影响.利用扫描电子显微镜和拉曼光谱分别表征了薄膜的形貌和质量,采用等离子体光谱诊断分析了薄膜生长过程的气相化学反应.结果表明:两种偏压方式下偏压的大小对薄膜的形貌及品质均有较大影响.相比直流...     

2024铝合金表面镀CrNx多层膜的研究

在2024铝合金上采用了二次浸锌的预处理方法,化学镀镍,电镀铜作为过渡层的特殊工艺,再利用磁过滤脉冲偏压电弧离子镀技术制备了Zn/Ni/Cu/Cr/CrNx多层梯度膜.利用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、显微硬度计和腐蚀测量仪等测试手段分析薄膜的成分、结构、表面形貌、显微硬度和耐腐蚀性等特性.结果表明:多层梯度膜提高了铝合金上CrNx涂层的结合力,能够有效地解决铝合金上镀硬质膜的热适配和晶格错配度大的难题,形成了良好力学梯度过渡的表面改性技术;Cr/CrNx膜使铝合金表面具有高的硬度和良好的耐蚀性,对轻合金表面涂覆超厚硬质膜具有一定的研究意义.     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...