磨机大齿轮加工工艺

针对磨机大齿轮的大尺寸、高精度和易变形特点,结合多年的加工经验,对整个加工过程进行工艺改进。采用两半把合、组对加工的方法实现车铣加工,通过“三车两铣”和人工时效来消除大齿轮的铸造与加工应力,解决了此类零件的加工难题。

基于特征模板的多组加工编程法

介绍了国内数控加工中存在的问题,结合广东省科委项目,提出了基于平面、曲面特征模板的多组加工编程法,并用实例验证了这种方法的正确性,极大地提高UG软件的加工编程效率,也解决了加工编程难以掌握的问题。

基于过程阻尼的钛合金丝材表面车削精整加工稳定性研究

针对航空紧固件原材料钛合金丝材盘圆细长结构特性和加工难度大的问题,采用无心车床进行钛合金丝材盘圆的表面车削精整加工。考虑车削后高精度表面质量的要求,为提高无心车床的加工稳定性,建立考虑过程阻尼效应的多自由度耦合颤振动力学模型。通过对模型求解,绘制无心车床刀盘切削系统稳定性叶瓣图进行稳定性分析,得到稳定可加工参数组。进一步分析刀具结构参数的影响,刀尖圆弧半径为0.1~0.3 mm、刀具前角为1°~2°和刀具后角为2°~5°时,可以获得设计安全性最高的稳定可加工参数组。通过搭建试验平台验证理论分析结论,所得到的刀具结构参数选择域和稳定可加工参数组可为钛合金丝材盘圆的表面精整加工提供参考。

UGCAM程序组、加工几何组的创建

主要介绍VGCAM组的创建，包括程序组创建、加工几何组创建。

平凡岗位展风采——记逊克县南山粮库加工厂区保管组长徐振艳

近几年，逊克县南山粮库保管组加工厂厂区的储粮管理工作，在县局多次检查中均受到领导好评，在全县五个粮库评比中名列前茅，五年来粮食损耗一直控制在0.15％以内。厂区之所以取得这么好的成绩，是因为这里有一个值得信赖的好带头人——组长徐振艳。徐振艳同志平时不善言辞，但却爱库如家，在平凡的工作岗位上兢兢业业、任劳任怨，为企业做出了不可磨灭的贡献。……

无铅皮蛋腌制剂和用腌制剂加工皮蛋的方法获专利

由浙江省农科院畜牧兽医研究所加工组(邮码:310021,电话:0571-86401243)陈黎洪等人发明的“无铅皮蛋腌制剂和用腌制剂加工皮蛋的方法”,前不久获国家发明专利(专利号:ZL97111312.2)。

Hot deformation behaviors of 35% SiC_p/2024Al metal matrix composites

The hot deformation behaviors of 35%SiCp/2024 aluminum alloy composites were studied by hot compression tests using Gleeble-1500D thermo-mechanical simulator at temperatures ranging from 350 to 500 °C under strain rates of 0.01-10 s-1. The true stress-true strain curves were obtained in the tests. Constitutive equation and processing map were established. The results show that the flow stress decreases with the increase of deformation temperature at a constant strain rate, and increases with the increase of strain rate at constant temperature, indicating that composite is a positive strain rate sensitive material. The flow stress behavior of composite during hot compression deformation can be represented by a Zener-Hollomon parameter in the hyperbolic sine form. Its activation energy for hot deformation Q is 225.4 kJ/mol. To demonstrate the potential workability, the stable zones and the instability zones in the processing map were identified and verified through micrographs. Considering processing map and microstructure, the hot deformation should be carried out at the temperature of 500 °C and the strain rate of 0.1-1 s-1.

Hot deformation behavior of TC11/Ti-22Al-25Nb dual-alloy in isothermal compression

The high-temperature flow behavior of TCll/Ti-22Al-25 Nb electron beam（EB） weldments was investigated by the isothermal compression tests at the temperature of 900-1060℃ and the strain rate of 0.001-10 s-（-1）.Based on the experimental data,the constitutive equation that describes the flow stress as a function of strain rate and deformation temperature is obtained.The apparent activation energy of deformation is calculated,which decreases with increasing the strain and the value is 334 kJ/mol at strain of 0.90.The efficiency of power dissipation η changes obviously with the variation of deformation conditions.Under the strain rates of 0.01,0.1 and 1 s-（-1）,the value of η increases with increasing the true strain for different deformation temperatures.While the value of η decreases with increasing the strain under the strain rates of 0.001 and 10 s-（-1）.The optimum processing condition is（t（opi）=1060℃,ε（opi）=0.1 s-（-1）） with the peak efficiency of 0.51.Under this deformation,dynamic recrystallization（DRX） is observed obviously in the microstructure of welding zone.Under the condition of 1060℃ and 0.001 s-（-1）,the deformation mechanism is dominated by dynamic recovery（DRV） and the value of η decreases sharply（η=0.02）.The flow instability is predicted to occur since the instability parameter ξ（ε）becomes negative.The hot working process can be carried out safely in the domain with the strain rate of 0.001-0.6 s-（-1） and the temperature of 900-1060℃.

Effect of initial microstructure on hot workability of 7085 aluminum alloy

The hot workability of 7085 aluminum alloys with different initial microstructures （as-homogenized and as-solution treated） was studied by isothermal compression tests at the deformation temperature ranging from 300 to 450 ℃ and the strain rate ranging from 0.0001 to 1 s 1. The strain rate sensitivity of the alloy was evaluated and used for establishing the power dissipation maps and instability maps on the basis of the flow stress data. The results show that the efficiency of power dissipation for the as-homogenized alloy is lower than that of the as-solution treated alloy. The deformation parameters of the dynamic recrystallization for the as-homogenized and as-solution treated alloy occur at 400 ℃, 0.01 s i and 450 ℃, 0.001 s-1, respectively. The flow instability region of the as-homogenized alloy is narrower than that of the as-solution treated alloy. These differences of the alloys with two different initial microstructures on the processing maps are mainly related to the dynamic precipitation characteristics.

Superplasticity of AZ31 magnesium alloy prepared by friction stir processing

Microstructure and tensile behaviors of AZ31 magnesium alloy prepared by friction stir processing（FSP） were investigated.The results show that microstructure of the AZ31 hot-rolled plate with an average grain size of 92.0 μm is refined to 11.4 μm after FSP.The FSP AZ31 alloy exhibits excellent plasticity at elevated temperature,with an elongation to failure of 1050% at 723 K and a strain rate of 5×10-4 s-1.The elongation of the FSP material is 268% at 723 K and 1×10-2 s-1,indicating that high strain rate superplasticity could be achieved.On the other hand,the hot-rolled base material,which has a coarse grain structure,possesses no superplasticity under the experimental conditions.

Influence of thermomechanical processing on microstructure,texture evolution and mechanical properties of Al-Mg-Si-Cu alloy sheets

Influence of thermomechanical processing on the microstructure, texture evolution and mechanical properties of A1-Mg-Si-Cu alloy sheets was studied systematically. The quite weak mechanical properties anisotropy was obtained in the alloy sheet through thermomechanical processing optimizing. The highly elongated microstmcture is the main structure for the hot or cold-rolled alloy sheets. H {001 } （110） and E { 111 } （110） are the main texture components in the surface layer of hot-rolled sheet, while ]/-fibre is dominant in quarter and center layers. Compared with the hot-rolled sheet, the intensities offl-fibre components are higher after the first cold rolling, but H {001 }（110） component in the surface layer decreases greatly. Almost no deformation texatre can be observed after intermediate annealing. And fl-fibre becomes the main texture again after the final cold rolling. With the reduction of the thickness, the through-thickness texture gradients become much weaker. The through-thickness recrystallization texture in the solution treated sample only has cubeyD {001 }（310） component. The relationship among thermomechanical processing, microstructure, texture and mechanical orouerties was analyzed.

Bioblock Method for Forest Vegetation Recovery in Japan

Bioblock method is a planting method for forest vegetation recovery by just depositing bioblocks without digging planting holes. The process includes collecting objective tree’s seeds or cuttings, nurturing seedlings, preparing and filling ＂ Kaminekkon＂, processing bioblock, and field planting. Seedlings can be planted without damaging root system, can be planted in hard ground or frozen soil and can be planted throughout the year.

从信息论谈小学语文讲读课结构改革

探讨小学语文讲读课教学过程的规律,是进行讲读课课堂结构改革的前提。本文从信息论角度就讲读课课堂结构作尝试性探讨。 小学语文讲读课教学的基本目标是:促使学生掌握语文知识,提高听、说、读、写能力;促进智力发展,开拓创造思维;陶冶美好的道德情操。讲读课结构的每个教学环节,虽然各有其功能,但必须服从这一总体目标。所以。

High temperature deformation behavior and optimization of hot compression process parameters in TC11 titanium alloy with coarse lamellar original microstructure

The high temperature deformation behaviors of α＋β type titanium alloy TC11 （Ti-6.5Al-3.5Mo-1.5Zr-0.3Si） with coarse lamellar starting microstructure were investigated based on the hot compression tests in the temperature range of 950-1100 ℃ and the strain rate range of 0.001-10 s-1. The processing maps at different strains were then constructed based on the dynamic materials model, and the hot compression process parameters and deformation mechanism were optimized and analyzed, respectively. The results show that the processing maps exhibit two domains with a high efficiency of power dissipation and a flow instability domain with a less efficiency of power dissipation. The types of domains were characterized by convergence and divergence of the efficiency of power dissipation, respectively. The convergent domain in a＋fl phase field is at the temperature of 950-990 ℃ and the strain rate of 0.001-0.01 s^-1, which correspond to a better hot compression process window of α＋β phase field. The peak of efficiency of power dissipation in α＋β phase field is at 950 ℃ and 0.001 s 1, which correspond to the best hot compression process parameters of α＋β phase field. The convergent domain in β phase field is at the temperature of 1020-1080 ℃ and the strain rate of 0.001-0.1 s^-l, which correspond to a better hot compression process window of β phase field. The peak of efficiency of power dissipation in ℃ phase field occurs at 1050 ℃ over the strain rates from 0.001 s^-1 to 0.01 s^-1, which correspond to the best hot compression process parameters of ,8 phase field. The divergence domain occurs at the strain rates above 0.5 s^-1 and in all the tested temperature range, which correspond to flow instability that is manifested as flow localization and indicated by the flow softening phenomenon in stress-- strain curves. The deformation mechanisms of the optimized hot compression process windows in a＋β and β phase fields are identified to be spheroidizing and dynamic recrystallizing controlled by self-diffusion mechanism, respectively. The microstructure observation of the deformed specimens in different domains matches very well with the optimized results.

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溪洛渡泄洪洞弧形闸门制造工艺技术

溪洛渡泄洪洞弧形闸门单套质量达703.27t,是国内目前已完工的单重最大的弧形闸门,在其制造过程中,制定了先进的工艺措施,采用合理的焊接坡口和焊接工艺控制弧形闸门的焊接变形,采用特定的太拼方法和加工工艺实现弧形闸门整体制作达到技术标准,其制造工艺技术可为大型弧形闸门的制造提供技术参考。

Constitutive behavior, microstructural evolution and processing map of extruded Al-1.1Mn-0.3Mg-0.25RE alloy during hot compression

Hot compression tests of an extruded Al-1.1Mn-0.3Mg-0.25RE alloy were performed on Gleeble-1500 system in the temperature range of 300-500 ℃ and strain rate range of 0.01-10 s-l. The associated microstructural evolutions were studied by observation of optical and transmission electron microscopes. The results show that the peak stress level decreases with increasing deformation temperature and decreasing strain rate, which can be represented by a Zener-Hollomon parameter in the hyperbolic-sine equation with the hot deformation activation energy of 186.48 kJ/mol. The steady flow behavior results from dynamic recovery whereas flow softening is associated with dynamic recrystallization and dynamic transformation of constituent particles. The main constituent particles are enriched rare earth phases. Positive purifying effects on impurity elements of Fe and Si are shown in the Al-l.lMn-0.3Mg-0.25RE alloy, which increases the workability at high temperature. Processing map was calculated and an optimum processing was determined with deformation temperature of 440-450 ℃ and strain rate of 0.01 s-1.

Hot working behavior of near alpha titanium alloy analyzed by mechanical testing and processing map

The hot deformation characteristics of the Ti-5.7Al-2.1Sn-3.9Zr-2Mo-0.1Si(Ti-6242S)alloy with an acicular starting microstructure were analyzed using processing map.The uniaxial hot compression tests were performed at temperatures ranging from 850 to 1000℃and at strain rates of 0.001-1 s-1.The developed processing map was used to determine the safe and unsafe deformation conditions of the alloy in association with the microstructural evolution by SEM and OM.It was recognized that the flow stress revealed differences in flow softening behavior by deformation at 1000℃compared to the lower deformation temperatures,which was attributed to microstructural changes.The processing map developed for typical strain of 0.7 in two-phase field exhibited high efficiency value of power dissipation of about 55%at 950℃and 0.001 s-1,basically due to extensive globularization.An increase in strain rate and a decrease in temperature resulted in a decrease in globularization ofαlamellae,whileαlamellar kinking increased.Eventually,the instability domain of flow behavior was identified in the temperature range of 850-900℃and at the strain rate higher than 0.01 s-1 reflecting the flow localization and adiabatic shear banding.By considering the power efficiency domains and the microstructural observations,the deformation in the temperature range of 950-1000℃and strain rate range of 0.001-0.01 s-1 was desirable leading to high efficiencies.It was realized that(950℃,0.001 s-1)was the optimum deformation condition for the alloy.

Fatigue strength and microstructure evaluation of Al 7050 alloy wires recycled by spray forming,extrusion and rotary swaging

Recycled high-strength aluminum alloys have limited use as structural materials due to poor mechanical properties. Spray forming remelting followed by hot extrusion is a promising route for reprocessing 7 xxx alloys. The 7050 alloy machining chips were spray formed, hot extruded, rotary swaged and heat-treated in order to improve mechanical properties. Microstructures, tensile properties and fatigue strength results for a 2.7 mm-diameter recycled wire are presented. Secondary phases and precipitates were investigated by XRD, SEM, EBSD, TEM and DSC. As-swaged and heat-treated(solution and aging) conditions were evaluated. Mechanical properties of both conditions outperformed AA7050 aerospace specification. Substantial grain refinement resulted from the extensive plastic deformation imposed by rotary swaging. Refined micrometric and sub-micrometric Al grains, as well as coarse and fine intermetallic precipitates were observed. Subsequent solution treatment resulted in a homogeneous, recrystallized and equiaxed microstructure with grain size of 9 μm. Nanoscale GP(I) zones and η′ phase precipitates formed after aging at 120 ℃, imparting higher tensile(586 MPa) and fatigue(198 MPa) strengths.

Hot deformation behavior of a Sr-modified Al-Si-Mg alloy:Constitutive model and processing maps

Isothermal compression experiments were conducted to study the hot deformation behaviors of a Sr-modified Al-Si-Mg alloy in the temperature range of 300-420°C and strain rate range of 0.01-10 s-1.A physically-based model was developed to accurately predict the flow stress.Meanwhile,processing maps were established to optimize hot working parameters.It is found that decreasing the strain rate or increasing the deformation temperature reduces the flow stress.The high activation energy is closely related to the pinning of dislocations from Si-containing dispersoids.Moreover,the deformed grains and the Si-containing dispersoids in the matrix are elongated perpendicular to the compression direction,and incomplete dynamic recrystallization(DRX)is discovered on the elongated boundaries in domain with peak efficiency.The flow instability is mainly attributed to the flow localization,brittle fracture of eutectic Si phase,and formation of adiabatic shear band.The optimum hot working window is 380-420°C and 0.03-0.28 s-1.