CoCl2在Ni-P基化学沉积中的作用

在Ni-P基化学沉积液中加入氯化钴,得到Ni-Co-P合金镀层,与Ni-P镀层相比较其性能得以改善。研究了氯化钴对化学沉积所起的作用及其影响机制,结果表明:加入适量的CoCl2可有效提高镀层的硬度和耐热溶液腐蚀性能,并能抑制镀层的晶化,提高其晶化温度。     

New inverse method for identification of constitutive parameters

A new inverse method by coupling iSIGHT and ABAQUS was proposed to determine the constitutive parameters of Al2O3sf/LY12 composite deforming at elevated temperature. It combined the merits of the f＇mite element simulation and optimization technique. The direct model was simulated with finite element code ABAQUS. The inverse problem associated with the identification of the constitutive parameters was expressed as a least square optimization problem. The direct simulation and the parameters optimization were implemented in iSIGHT integrated environment. The aim was to match the output of the direct simulation with the experiment data. The capability of the proposed inverse method was demonstrated through the identification of constitutive parameters of Al2O3sf/LY12 composite. The proposed new inverse method is also applicable to other parameters identification which is hardly determined through experiments or direct analytical method.     

Behavior of calcium silicate in leaching process

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Properties of Co-doped N-type FeSi2 processed by mechanical alloying

Iron-silicide was produced with a mechanical alloying process and consolidated through vacuum hot pressing. The as-milled powders were of metastable state and fully transformed into the ß-FeSi₂ phase through subsequent isothermal annealing. The as-consolidated iron silicides consisted of an untransformed mixture of α-Fe₂Si₅ and ?-FeSi phases and a partially transformed β-FeSi₂ phase was found in the low density compact. Isothermal annealing was carried out to induce transformation into a thermoelectric semiconducting β-FeSi₂ phase. The transformation behavior of the β-FeSi₂ was investigated utilizing DTA, SEM, and XRD analyses. Isothermal annealing at 830°C in vacuum led to a thermoelectric semiconducting β-FeSi₂ phase transformation, but some residual metallic α and ?-phases were unavoidable even after 96 hours of annealing. The iron silicide microstructures were investigated using SEM and TEM. The mechanical and thermoelectric properties of the β-FeSi₂ materials before and after isothermal annealing are characterized in this study.     

单晶高温合金/Al2O3型壳界面行为研究

采用直接浇注法制备金属型壳界面行为试样，其金属为单晶高温合金DD3、DD6，型壳为Al2O3。通过金相显微镜、扫描电镜及能谱分析对试样表面进行研究。结果表明，采用Al2O3型壳铸造出的DD3、DD6单晶铸件外表面光洁，Al2O3型壳可用于DD3、DD6单晶高温合金的熔模铸造工艺。     

氧化剂对Cu-Al2O3复合材料微观组织的影响

研究了一种新型简化内氧化工艺,并制备了不同氧源系数的Cu-Al2O3复合材料。用SEM、TEM等分析手段对所制备复合材料烧结态的微观组织进行了研究。结果表明,该简化工艺成功制备了Cu-Al2O3复合材料,在铜基体上弥散分布着大量细小的γ-Al2O3颗粒,其粒径为5~20nm,颗粒间距为25~60nm,当氧源系数(k)为1.20时,压制粉末经烧结(950℃,4h)后全部完成内氧化,此氧化剂含量为最佳的内氧化氧化剂添加量。     

基于DSP320F2812的数字化CO2焊机研制

设计了数字化CO2焊机的硬件结构,并根据CO2焊接工艺的特点,编写了相应的控制软件,实现了整个焊接系统的数字化.试验结果表明,基于DSP320F2812芯片控制的焊接电源具有良好的动特性,获得了较好的控制效果,为控制策略的智能化和最优化提供了良好的平台.     

Extraction-chromatographic Separation of Microamount Scandium(Ⅲ)with HEH(EHP) Resin and Its Analytical Application

The optimum conditions for the extraction-chromatography by using 2-ethylhexyl-2-ethylhexyl-phosphonate resin to separate scandium(Ⅲ)from large amounts of other metal ions were reported.A me-thod for the separation and determination of microamount of scandium has been developed.This methodgives higher accuracy and reproducibility than solvent extraction with PMBP,especially,for the samplescontaining high content of titanium.Many shortcomings of other methods ever reported can be overcomeby the present method.     

快速凝固粉末冶金TiB2颗粒增强AlFeVSi耐热铝合金

利用快速凝固粉末冶金方法制备了TiB2颗粒增强Al-8.5Fe-1.3V-1.7Si耐热铝合金试样以及不含TiB2颗粒的基体合金试样,通过光学显微镜、扫描电镜分析了其显微组织和断口形貌,采用X射线衍射进行了物相分析,并进行力学性能测试.结果发现,TiB2颗粒能有效地添加到Al-8.5Fe-1.3V-1.7Si耐热铝合金基体中,并能有效地抑制平衡相Al13Fe4的析出,且能细化晶粒,TiB2颗粒的存在使得粒度小于74μm粉末冶金合金挤压试样的室温强度高达454.1 MPa,屈服强度达407.8 MPa,延伸率保持在7.7%;350℃高温强度稳定在210 MPa以上,延伸率稳定在7.7%以上.     

冷却介质对ZG30CrMn2Si2NiMo组织和力学性能的影响

研究了不同冷却介质对ZG30CrMn2Si2NiMo铸钢力学性能及组织的影响.试验结果表明,奥氏体化后空冷ZG30CrMn2Si2NiMo组织为板条贝氏体型铁素体和残余奥氏体组织,奥氏体化后淬火ZG30CrMn2Si2NiMo组织为板条马氏体、贝氏体型铁素体和残余奥氏体组织.ZG30CrMn2Si2NiMo获得板条马氏体、贝氏体型铁素体和残余奥氏体组织时,具有良好的力学性能.