INVESTIGATION OF NANO AND MICRO ALUMINA PARTICLES IN ALUMINUM MATRIX BY USING POWDER METALLURGY TECHNIQUE

number: 
3793
إنجليزية
Degree: 
Author: 
Ban Ali Sabri
Supervisor: 
Dr. Abdul Rahman N. Abed
year: 
2017

In this research, ceramic alumina particles are used as an additive to the aluminum  metal in order to fabricate new composite and to study the alumina effect on the  improvement of properties and characterizing the new properties of the composites taking into  consideration the main aluminum drawback property of low wear  resistance. In the presented thesis, micro and nano alumina particles have been used  as a reinforcement for the aluminum matrix by using powder metallurgy technique  and with three different percentages of alumina (5, 10 and 15wt.%). After mixing of powders, compaction was done with four compacting pressures of (300, 400, 500 and 600MPa), identification of samples compaction pressure was based according  to less porosity obtained. Two shapes of specimens have been prepared for examinations, one is a disc specimens with 11mm diameter and 5 mm thickness,  the second one is cylindrical specimens with 11mm diameter and 16.5mm length,  the compaction pressure was 500MPa, according to porosity measurements .Specimens have been pressure less sintered in a vacuum tube furnace for two hours time long under a subjected temperature of 500ºC. Physical and mechanical properties of the sintered pure aluminum, micro composite and nano composite samples have been studied. Relative density, density and porosity, hardness and compression strength were investigated. Microstructure, particles distribution, agglomeration and grain sizes were studied by atomic force microscopy (AFM) and granularity accumulation distribution. Dry sliding wear for each of micro and nano alumina composites has been investigated taking into  consideration the wear sliding distance and three different loading conditions (500,  1000 and 1500g  ]hrough the physical study of the relative density of the obtained  composites, it has been noticed in micro alumina composites that the relative  density are reducing with the increase in micro alumina increase, while, the relative  density for the three percentage of additives was less than the relative density of the