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استقصاء الخواص الفيزيائية والميكانيكية لنحاس الومينا متدرج وظيفيا == Investigation Of Physical And Mechanical Properties Of Cu/Al2O3 Functionally Graded Materials
Author name:
رؤى حاتم كاظم
Supervisor name:
عبد الرحمن كاظم عبد علي
General topic:
Production engineering metallurgy and materials
Specific topic:
Metals Engineering
Degree:
Master
University:
University of Babylon - Faculty Of Materials Engineering - Department Of Metallurgical Engineering
Language:
English
University location:
Babylon
First pages:
46T186 - p.pdf
Abstract:
One of the most important smart material is the functionally graded materials, which had more increasing attention in different engineering applications.In this study, five - layered stepwise Cu/Al2O3 as functionally graded materials have been prepared from copper powder with five percentage of alumina powder as (5, 10, 20, 30, and 40 Wt%) by using powder metallurgy technique. Mixing of copper (34.32 ?m) and alumina (1.439 ?m) powders for two hours and then several disk sample with dimensions (14mm diameter and 10mm thickness) and cylindrical specimens with (18mm diameter and 27 height) have been compacting at different compacting stresses (550, 650 and 750 MPa). However, sintering of specimens for three hours at 850?C under vacuum about has been achieved.Several physical tests such as porosity, electrical resistance and thermal conductivity, X - ray diffraction, X - ray Fluorescence and Particale size analysis have been achieved. Furthermore, Microstructure and mechanical tests such as hardness, compression, double shear and dry sliding wear have been done for preparing samples from composite and functionally graded material.Numerical modeling using finite element analysis by ANSYS software has been presented for copper/alumina joints and compare with copper/alumina functionally graded materials.From the several experimental results, it is clear that the best compacting pressure was 650 MPa is determined by measuring green density at different compacting pressure, hardness increased with the increasing additive percentage of alumina, hardness resultschange in each layer by producing functionally graded materials (FGM) according to the percentage of the harder constituent (i.e. Al2O3) from 53 to 113 HV at compacting pressure 650 MPa, While the shear strength decreases with alumina increased from 72 MPa for layer one to 28 MPa for layer five at compacting pressure 650 MPa. The Wear rate increases as the time and load is increased. The wear resistance increased with increasing contain of Alumina. Results from the numerical modeling, it is clear that residual thermal stresses gradually decreased from the interface to the edges of functionally graded sample whereas in Copper/Alumina joint there is very high thermal residual stress in the joint interface.
