超声复合磁力研磨加工镍基合金GH4169异形管

为解决镍基合金GH4169异型管内壁难研磨及研磨不均匀问题,采用超声复合磁力研磨光整加工方法进行试验。分析在超声复合磁力研磨条件下,主轴转速、加工间隙、超声频率和超声振幅对异形管内壁表面质量的影响。结果表明：在超声轴向频率为19 kHz、振幅19 μm,主轴转速1000 r/min,磁性磨粒平均粒径250 μm,加工间隙2 mm加工条件下,加工30 min后,管件内壁表面粗糙度Ra由原始的2.4 μm降至0.31 μm。通过在管件内部添加圆柱形辅助磁极,使得内外两磁极形成闭合磁场回路,增加磁场力的作用。辅助磁极连接高频轴向超声振动,使得吸附在磁极上的磁性磨粒在旋转运动和轴向高频振动复合作用下划擦、研磨管件内表面。由于研磨轨迹发生交叉复杂化,使得异型管内壁研磨后的表面质量和表面粗糙度得到明显提高;管件内壁表面残余应力由拉应力+52 MPa转变为压应力-48 MPa,表面应力状态得到较好的改善。     

旋转超声辅助磁力研磨镍基合金参数优化设计及分析

目的 针对镍基高温合金进行旋转超声磁力研磨加工试验,通过响应面法分析主轴转速、超声频率、超声振幅、粒径交互作用对工件表面的影响。方法 在磁力研磨基础上添加旋转超声高频轴向机械振动,通过磁性研磨粒子对工件表面的垂直冲击,增加研磨压力以及磁性研磨粒子的翻滚动作,完成旋转超声辅助磁力研磨,测定表面粗糙度、表面残余应力等性能参数。采用响应面法分析主轴转速、磁性研磨粒子粒径和超声频率的交互作用对试验的影响规律,拟合出最佳工艺参数条件。结果 在试验条件下得出,主轴转速1000 r/min、磁性研磨粒子粒径250 μm、超声频率19 kHz、超声振幅19 μm的加工工艺组合效果最佳,并与响应面法优化参数后的结果相一致。根据优化参数进行试验,经过40 min研磨加工后,Ra从加工前的3.2 μm降至0.072 μm,工件表面各位置粗糙度均匀,表面质量较好。工件内部残余拉应力从+51 MPa转变为残余压应力-121 MPa。结论 旋转超声辅助磁力研磨加工后,工件表面均匀性提高,原始工件表面的凹坑、凸起、表面微裂纹等缺陷被完全去除,表面形貌和表面质量较好。该工艺加工效率较高,工件内部可得到良好的应力状态。     

旋转超声辅助磁力研磨镍基合金试验研究

对现有新材料镍基高温合金进行旋转超声辅助磁力研磨试验研究。探讨该方法及工艺参数对工件表面微裂纹、褶皱、划痕等表面缺陷问题的去除效果。试验结果表明:旋转超声辅助磁力研磨光整加工磁极转速为1 000 r/min,磁性研磨粒子平均粒径为250 μm,超声振动频率为19 kHz时比传统磁力研磨效果有显著提高,工件表面粗糙度从R_a 3.4 μm降到R_a 0.07 μm;研磨后其内部应力由拉应力+46 MPa转变为压应力-126MPa,得到了良好的表面应力状态。在相同磁力研磨加工条件和试验参数下,该方法与传统磁力研磨加工进行实验对比,旋转超声辅助磁力研磨方法通过添加轴向高频旋转超声冲击,得到良好的工件表面质量及表面粗糙度;加工后工件表面划痕、褶皱、微裂纹基本去除,表面质量及表面微观形貌有显著改善。     

基于3D打印航空发动机喷油管磁力研磨试验研究

目的针对镍基合金GH4169航空发动机喷油管进行磁力研磨光整加工试验研究,分析内置辅助磁极磁力研磨对工件内表面及交叉孔相贯线去毛刺的效果。方法利用磁粒研磨内置辅助磁极光整加工对工件内表面及内交叉孔相贯线处进行磁力研磨加工,通过研磨粒子与工件之间的划擦、磨削等运动,提高工件表面质量和去除内交叉孔相贯线处的毛刺。结果磁轭转速为1000 r/min,加工间隙为6 mm,采用圆柱形辅助磁极及平均粒径为250μm的磁性磨料时,其加工效果比传统的加工效果好,且效率更高,工件表面粗糙度从原始的5.8μm降至0.47μm(Ra0.5μm),内交叉孔相贯线处的毛刺明显被去除,且由于磁性研磨粒子的研磨作用,可对其进行二次光整加工。结论通过磁力研磨内置辅助磁极光整加工方法,原始工件内表面存在的褶皱、微裂纹明显得到改善,交叉孔相贯线处的毛刺也明显被去除。试验选用磁性研磨粒子粒径为250μm时,研磨效果最佳。通过磁力研磨光整加工后,管件能够得到良好的表面效果,提高了管件的综合性能。     

电解-磁力复合研磨TA18钛合金管内表面研究

为了改善TA18合金制造零部件的表面质量,降低其表面粗糙度,提出了一种高效率的电解-磁力复合研磨加工方法,采用电解的钝化作用辅助磁力研磨,对比了复合加工与单纯磁力研磨加工前后表面粗糙度与表面形貌的变化,通过单因素试验分析磁极转速、电解电压对表面质量的影响。结果表明:电解-磁力复合加工实现了对TA18管内表面的精密研磨,与单纯磁力研磨相比,经过50min加工,表面粗糙度由原始的0.9μm下降到0.08μm,残余应力有效降低,表面微观形貌得到明显改善,有效提高了工件疲劳强度。     

超声振动辅助电解磨削Hastelloy X内孔表面粗糙度规律预测分析

通过单因素试验并结合响应曲面分析法,重点分析超声振动辅助电解磨削Hastelloy X内孔加工中主轴转速、超声振幅及磨头目数对孔内壁表面粗糙度的影响规律.结果表明:在选取的优化工艺参数范围内,超声振幅对超声辅助电解磨削表面粗糙度的影响最大,磨头目数次之,主轴转速最小.通过参数优化,在主轴转速10836 r/min、磨头目数1000、超声振幅3.3μm的条件下,可得到内壁表面粗糙度为Ra0.25μm的小孔,这为进一步优化复合加工参数及改善表面质量提供了依据.     

弹性磁极磨头磁力研磨TC4钛合金的工艺优化

尽管磁力研磨具有随形加工特性，但使用小磨头磁力研磨大扭曲度工件时，磨头在工件不同位置处的间隙差异，给磁力研磨加工带来了挑战。为了改善磁力研磨的加工表面质量，进一步减小工件间隙差异对表面粗糙度的影响，设计了一种以聚氨酯弹性体为磁极载体的弹性磁极磨头，对其磁场进行仿真分析并验证。在试验中使用黏结法制备的金刚石磁性磨料，比较不同加工间隙下聚氨酯弹性磁极磨头与普通磁极磨头的研磨加工性能，探索主轴转速、进给速度和磨料粒度对钛合金表面粗糙度的影响规律。结果表明：在工艺参数相同的情况下，聚氨酯弹性磁极磨头的加工性能优于普通磁极磨头的；使用聚氨酯弹性磁极磨头，在主轴转速为800 r/min，加工间隙为2.0 mm，进给速度为5 mm/min，磨料粒径范围为62～90μm时，磁力研磨加工效果最优，经过12 min的研磨加工，TC4钛合金的表面粗糙度R_a从最初的0.350μm降至0.039μm，表面粗糙度改善率达到89%。试验结果验证了聚氨酯弹性层的弹性及仿形特性对TC4钛合金加工表面质量的提升作用。     

磁力研磨光整加工ZrO2陶瓷材料试验研究

目的利用磁力研磨光整加工技术提高ZrO_2陶瓷材料的表面质量,并探究主要工艺参数对ZrO_2陶瓷表面质量的影响规律,得到磁力研磨光整加工陶瓷材料的最优工艺参数组合。方法采用开米字槽的研磨磁极头,利用球形磁性磨料对ZrO_2陶瓷材料进行磁力光整加工。借助XK7136C数控铣床对工件材料进行加工试验,探究其表面改性能力。借助白光干涉仪和扫描电镜对抛光后的表面形貌进行检测分析,采用单因素试验法探究主轴转速、加工间隙、磨料填充量和进给速度对表面粗糙度的影响,并设计合理的交互正交优化试验,寻求最佳的工艺参数组合。结果在磁力研磨光整加工ZrO_2陶瓷材料过程中,当转速S=1000 r/min,加工间隙δ=2.5 mm,磨料填充量m=2.5 g,进给速度v=15 mm/min时,工件平均表面粗糙度可由研磨前的1.950μm下降到0.493μm。通过白光干涉仪和扫描电镜等对材料表面的检测分析可知,加工后工件的表面毛刺大大减少,表面质量得到了改善。结论采用磁力研磨光整加工技术和最佳参数组合,可以有效地降低ZrO_2陶瓷材料的表面粗糙度,得到高质量的表面。     

超声振动复合研磨K9光学玻璃工艺研究

目的探究超声振动复合研磨对光学玻璃研磨可行性,通过响应面法寻求超声振动研磨最优的工艺参数组合。方法在传统研磨装置基础上,添加超声振动装置、蠕动泵、旋转工作台构成超声振动复合研磨装置。添加轴向超声高频振动提高研磨效率,添加旋转工作台提高研磨均匀性,添加蠕动泵便于循环和更新研磨液。利用响应面法优化超声振动复合研磨加工中的主轴转速、振动频率、加工间隙三个变量参数,并进行实验研究,可得出两两变量关联度,从而得出研磨中影响最大的因素。结果通过响应面优化后得到超声振动复合研磨最佳工艺参数为主轴转速1000 r/min、加工间隙0.4 mm、振动频率12 kHz,主轴转速和间隙参数对工件表面研磨加工的影响较大。经25 min研磨,无超声振动的传统研磨方法使表面粗糙度值Ra从0.3μm下降到0.1μm;增加超声振动复合研磨使表面粗糙度值Ra从0.3μm下降到0.04μm。结论经超声振动复合研磨后,光学玻璃表面存在的凹坑、凸起均得到了有效去除,表面粗糙度值下降快,表面形貌均匀、平整。     

超声波辅助磁力研磨TC4薄壁细长管内表面研究

针对传统磁力研磨对长径较大的TC4薄壁细长管内表面进行精密抛光时,研磨效率低、材料去除量小且加工后表面质量差的问题,提出了一种超声振动辅助磁力研磨技术。采用超声振动发生装置辅助磁力研磨,通过对辅助磁极添加轴向振动,实现对TC4薄壁细长管内表面的高效精密抛光。对比添加超声振动前后工件的表面质量以及研磨效率的变化,分析了不同振动频率对工件的表面粗糙度值以及材料去除量的影响。结果表明:经过40min的研磨加工,添加了超声振动后工件的表面质量得到明显改善,表面粗糙度值由Ra1.4μm降至Ra0.25μm,材料去除量可达到50mg,高频率的振动有利于提高研磨效率以及改善工件表面的加工质量。     

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.     

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.     

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.     

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.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.     

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。