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51.
高速正交切削SiCp/Al复合材料切削温度仿真研究 总被引:1,自引:0,他引:1
使用ABAQUS有限元软件对高体分SiCp/Al复合材料的颗粒和基体进行分别定义,仿真研究了高速切削复合材料时的温度场,分析了切削过程中切削用量和刀具角度对工件切削温度的影响。结果表明:在切削过程中,与刀具接触位置的颗粒温度较高且应力值较高;SiC颗粒的温度较Al基体的温度低;第一变形区发现一条沿着剪切角方向非常明显的温升带。在稳定切削阶段,与刀尖接触位置的工件温度较高,且应力集中现象总是发生在SiC颗粒上。随着切削深度和切削深度的增加,切削过程中工件的最高温度均随之增加;随着刀具前角和后角的增大,切削过程中工件的最高温度均随之降低。 相似文献
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液固分离法近净成形SiC_p/Al电子封装壳体的组织和性能(英文) 总被引:2,自引:0,他引:2
采用液固分离工艺制备高SiC体积分数Al基电子封装壳体(54%SiC,体积分数),借助光学显微镜和扫描电镜分析壳体复合材料中SiC的形态分布及其断口形貌,并测定其物理性能和力学性能。结果表明:SiCp/Al壳体复合材料中Al基体相互连接构成网状,SiC颗粒均匀镶嵌分布于Al基体中。复合材料的密度为2.93 g/cm3,致密度为98.7%,热导率为175 W/(m·K),热膨胀系数为10.3×10-6K-1(25~400°C),抗压强度为496 MPa,抗弯强度为404.5 MPa。复合材料的主要断裂方式为SiC颗粒的脆性断裂同时伴随着Al基体的韧性断裂,其热导率高于Si/Al合金的,热膨胀系数与芯片材料的相匹配。 相似文献
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《Science & Technology of Welding & Joining》2013,18(6):561-566
AbstractThe isolation coupling device is designed based on the principle of high pass filter circuit, which can achieve isolation and coupling between ac welding power and ultrasonic frequency excitation source. In addition, ac arc ultrasonic vibration is obtained successfully. The plasma arc in situ welding of SiCp/6061Al was performed using two different processes. The first process is that the plasma gas is argon nitrogen mixture and the filler material is flux cored wire (Al–5Ti–5Si); the other process is that the plasma gas is argon and the filler material is flux cored wire (Al–15Ti–3Si). The two joints are respectively enhanced by nitride and Al3Ti, which were obtained in these processes. After arc ultrasonic vibrations were imposed on the two welding processes, it was revealed that arc ultrasonic improved the distribution of the new nitride phases and optimised the morphology of Al3Ti to improve the mechanical properties of joints that reached 246 and 263 MPa. Fracture analysis showed that the improvement of the mechanical properties resulting from Al3Ti is better than that from nitride under the effect of arc ultrasonic. 相似文献
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A method of concentration analysis based on X-ray photoelectron spectroscopy (XPS) results was introduced. The concentration of Ce-rich conversion coating on the anodized Al based metal matrix composites Al6061/SiCp was then studied according to this method. The results revealed that the Ce conversion coating on the anodized Al6061/SiCp consisted of Al oxide, Ce oxide and Ce hydroxide. The state of Ce element exhibited the mixture of Ce3+ and Ce4+. Some of Celll was oxidized to be CelV in the outer layer coating. 相似文献
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The dynamic mechanical property of particle‐reinforced ethylene–propylene–diene monomer (EPDM) matrix composites has been studied by using a dynamic mechanical thermal analyzer (DMTA). The individual composite has been reinforced with the various reinforcing particles as follows: silicon carbide particles (SiCps) of 60 μm in average diameter with various volume fractions (i.e., 10–40%); copper (Cu) and aluminum (Al) particles with 20 vol %; and SiCps with 6 and 36 μm in different average diameters with 20 vol % over the total composite volume. It is shown from the experimental results that the dynamic elastic modulus values increase and the composites with 40 vol % SiCps exhibit higher tan δ values through the entire rubbery phase after the glass transition region compared with the composites with lower particle volume percentages. This shows that the composites with 20 vol % Cu particles have the higher dynamic elastic modulus but the lower peak tan δ value than the composites with other particles of 20 vol % do. Scanning electron microscopy results show that the effective particle volume in the composite with Cu particles is higher than the other composites, although the same particle volume fraction of 20% has been used. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1595–1601, 2003 相似文献
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将纯Al颗粒和SiC颗粒混合,室温下采用高压扭转变形(HPT)制备试样,测定不同工艺参数下试样表面的显微硬度,绘制显微硬度—扭转半径曲线图,分析各试样的硬度分布特征。结果表明:由于高压扭转变形应变量的影响,SiCp/Al复合材料经HPT变形后,各试样表面硬度沿径向呈递增分布,边缘硬度值受飞边的影响较大;单一尺寸SiC颗粒强化的试样通过增大加载压力、增大扭转圈数或提高SiC颗粒体积分数可以提高试样的显微硬度值;采用双尺寸SiC颗粒最佳粒径配比或最佳体积配比更有利于提高试样硬度,通过优化双尺寸SiC颗粒粒径配比或体积配比,可以获得更高的试样硬度,且硬度分布更加均匀。 相似文献