الفهرس 
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Abstract
Copper nanocomposite reinforced with nano Al2O3, MWCNTs or hybrid of both are prepared by electroless chemical deposition of Cu on nano Al2O3, MWCNTs or hybrid of both followed by powder metallurgy technique. The present work represents the experimental examination of the additions of nano Al2O3, MWCNTs or hybrid of both on the properties of Cu nanocomposites. The object is the enhancement of the dispersion of weight fractions of nano Al2O3 or MWCNTs nanoparticles in the Cu matrix and improvement the wettability between the Cu matrix with nano Al2O3, MWCNTs to obtain a material suitable for electronic, mechanical and electrochemical applications. Nano Al2O3 are used 3, 6, 9 and 12 wt.%
& 0.4, 0.8 and 1.2wt.% MWCNTs or (9wt.%Al2O3 -1.2wt.% MWCNTs) hybrid were considered to highlight their effects on the properties of the prepared nanocomposite. High energy ball mill technique is applied for the powder mixing, then compaction and sintering at 950 oC for 2h in a controlled atmosphere furnace. Microstructural examination of the distribution of nano Al2O3 and MWCNTs in the Cu matrix is studied using FE-SME. The relative density was measured according to Archimedes principle. Microhardness, wear resistance and coefficient of friction were studied. Both thermal and electrical conductivities were estimated. Also,
the electrochemical behavior of ZnO film deposition on the surface of the prepared composites was recorded. The effect of nano Al2O3, MWCNTs or hybrid of both on the corrosion resistance of Cu composites was studied. The results indicated that the relative density was decreased with increasing the content of nano Al2O3 & MWCNTs or hybrid nanoparticles. The microhardness increased with increasing of nano Al2O3 content. Electrical resistivity is increased gradually by the addition of nano Al2O3, MWCNTs, but decreased with the hybrid of both nanocomposites content. The thermal conductivity decreased by increasing Al2O3, MWCNTs, but increased with the hybrid of both nanocomposites content. The maximum current density showed a maximum at -142 mA.cm-2 for 9wt.% Al2O3. The presence of MWCNTs by ratio 0.8wt.% and 1.2wt.% gradually promotes ZnO deposition. The deposition rate increased gradually with increasing MWCNTs samples. The current density presented a maximum at -110 mA.cm-2 with 1.2wt.% MWCNTs. The resistance polarization increased with increasing Al2O3 percentage from 0 up to 9 wt.%. The resistance polarization achieved a maximum value of 79 Ohms.cm2 at 9 wt.% Al2O3 samples. The resistance polarization increased gradually with increasing MWCNTs percentage and attained a maximum value of 115 Ohms.cm2 at
1.2wt.%. The corrosion rate decreased gradually by addition of nano Al2O3
up to 9 wt.% and attained a minimum value of 2.93 mm/year with respect to 2.99 mm/year of Cu pure. The corrosion rate decreased with increasing MWCNTs from 0.8wt.% to 1.2wt.% and attained a minimum value of 3.08 mm/year with respect to 2.997 mm/y of Cu pure. The wear rate increased with increasing the normal load at all various velocities for all the measured samples. Wear rate of nano Al2O3 are lower than that of the pure Cu at all sliding speeds and loads and decreased by increasing Al2O3 content. Sliding wear rate increased with increasing sliding velocity for all the tested samples. The average coefficient of friction reduces by increasing applied loads for the fabricated samples. The Cu matrix displays deep grooves, whereas the nanocomposites show fine ones.