水溶性合成酯极压添加剂的不锈钢切削实验（英文）

为了了解新型的水溶性合成酯极压添加剂KLG-3的切削效果,用乳化液(10%KLG-3)进行AISI 304不锈钢车削实验,通过粗糙度、刀具寿命、刀具磨损、切屑和切削力的比较,了解该微乳化液与多种传统切削液及干切削的切削效果差异。结论显示:10%KLG-3在减少刀具磨损和改善加工表面光洁度方面有良好效果,优于大部分传统切削液,因此非常适合于不锈钢切削。KLG-3的微乳化液的综合切削效果相对干切削效果有显著改善,已经达到传统切削液效果,可以代替传统切削液使用。     

微量油膜附水滴绿色加工技术的研究

通过微量油膜附水滴切削液、干切削和乳化液的对比试验,研究微量油膜附水滴的切削效果。试验结果表明:与干切削和乳化液润滑比较,采用微量油膜附水滴不仅能够降低切削力,而且还能降低刀具的磨损。     

具有沟槽微织构的超硬材料刀具切削仿真与实验研究

目的 探究微织构置入切削刀具表面对切削性能产生的影响.方法 在具有沟槽微织构的超硬材料刀具上,设计了切削仿真与实验.基于流体动压射流和流体二次润滑,以J-C准则作为车削的本构关系,采用ABAQUS进行仿真.在相同条件下,对有无沟槽微织构的超硬材料刀具进行了三维切削Al6061模拟,并结合刀具应力和前刀面切削温度,对切削性能进行了分析.采用飞秒激光工艺制备了新型沟槽微织构超硬材料车刀,并在CA6136车床上进行单因素切削实验.结果 刀具在置入沟槽微织构后,不仅降低了摩擦副间的接触面积,而且在切削液的双重作用下,瞬时高温现象也得到了缓解.在干切削条件下,沟槽微织构刀具的前刀面不具有较好的减磨抗粘能力,刀具磨损较快.在切削液润滑、流体动压射流现象和沟槽微织构共同作用下,刀具的摩擦磨损状况得到很大改善,使用寿命得到延长.结论 综合切削仿真与实验结果可知,微织构置入切削刀具表面能够提升刀具切削性能并缓解刀具磨损情况.     

不锈钢纳米流体微量润滑车削实验研究

纳米流体微量润滑(NFMQL)是一种全新的微量润滑(MQL)增效技术,为了解其对不锈钢切削的效果,分别在干切削、浇注润滑、MQL和Al_2O_3颗粒的NFMQL条件下对SUS304不锈钢进行车削,比较切削力、切削温度、光洁度和刀具寿命的差异。实验结果显示:NFMQL冷却润滑效果要好于MQL,但比浇注润滑差;NFMQL比MQL更容易获得较小的切削力和切削温度、光洁度以及更长的刀具工作寿命,NFMQL对光洁度和刀具寿命改善显著。NFMQL改善不锈钢切削性能,适合在不锈钢切削中应用。     

硬质合金刀具干车削AISIH13的切削性能试验研究

干式和湿式(油基切削液)法用于YW2硬质合金刀具对AISIH13的变切削参数车削过程.测力仪(YDC-Ⅲ89B)及便携式粗糙度仪(TR100)分别测量切削力和零件表面粗糙度,工具显微镜(XGJ-1)及扫描电镜(S-3400N)用于刀具磨损分析.与湿式切削相比,干切削时的切削力较小,表面粗糙度值较低,刀具磨损程度稍低.粘结、崩刃分别为干、湿式切削时刀具磨损主要形式.     

新型微坑车刀切削304不锈钢降温机理分析研究

切削304不锈钢时,刀具温度高达750℃,高温集中在刀具切削刃近域,这加速了刀具的磨损,缩短了刀具的寿命。为了减小该区域的摩擦状况,降低该区域切削过程的温度,在刀具切削刃近域进行微坑结构设计。应用微坑车刀和原车刀切削304不锈钢,经仿真分析和切削实验,发现微坑车刀较原车刀,切削力降低,切削温度降低。通过切削力学模型分析、刀屑摩擦模型的研究和刀具磨损的对比,得出微坑车刀切削温度降低的形成机理。     

不锈钢切削加工中刀具切削参数的合理选择

阐述不锈钢的主要切削特点。为解决不锈钢加工困难的问题,从选择刀具材料、刀具角度、切削用量和切削液等方面对不锈钢的切削加工进行分析和研究。     

Si_3N_4基微纳米复合陶瓷刀具的高速切削性能与磨损机理

在亚微米Si3N4、TiC颗粒中添加纳米Si3N4、SiC颗粒,采用真空热压烧结工艺制备出STS微纳米复合陶瓷刀具,并对比STS刀具及FD-01刀具在PUMA200MA车削中心干切削淬硬40CrNiMo工件的切削性能。利用扫描电子显微镜(SEM)分析刀具前、后刀面的磨损形态,研究STS陶瓷刀具的磨损机理。结果表明:STS微纳米复合刀具材料具有较高的力学性能,抗弯强度达1000MPa,维氏硬度达19.5GPa。高速干切削40CrNiMo工件时,随着切削速度的增大,刀具后刀面磨损随之增大。切削速度越高,STS刀具优势越明显。两种刀具的磨损形态均主要为月牙洼磨损和后刀面磨损,磨损机制主要为磨粒磨损和粘结磨损。     

21世纪的切削液技术

1切削液技术的发展趋势 众所周知，切削液具有润滑、冷却、清洗及防锈等作用，对提高切削加工质量和效率、减少刀具磨损等均有显著效果。近十多年来，我国的切削液技术发展很快，切削液新品种不断出现，性能也不断改进和完善，特别是20世纪70年代末生产的水基合成切削液和近几年发展起来的半合成切削液（微乳化切削液）在生产中的推广和应用，为机械加工向节能、     

微织构车刀制备与SUS304钢高速微车削试验

针对高速微切削过程中微型车刀表面摩擦磨损严重的问题,利用表面非光滑微织构减摩减阻原理,在高速微切削用车刀表面利用激光加工技术制备了微槽、微坑织构,研究了激光加工参数与微织构形貌之间的关系;分析了微织构的摩擦学特性;利用自行研制的高速微车削单元进行微织构刀具及无织构刀具的高速微切削SUS304不锈钢的对比试验,从切削力、切削温度、刀屑接触状态、切屑形态以及已加工表面粗糙度对微织构车刀性能进行评价。结果表明:微槽、微坑织构均可以有效降低刀具表面摩擦因数;在高速微切削过程中可以减小切削力、切削温度,降低刀屑接触长度,改善切屑形态,尤其是微坑织构可明显改善表面质量,可以应用到SUS304不锈钢的高速微加工。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.