الفهرس 
Chapter 1: Introduction and Literature ReviewOnly 14 pages are availabe for public view
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Abstract
This work was initiated to synthesize and characterize of Ti-Zr-N coatings prepared by pulsed magnetron sputtering (PMS) technique. The samples were tested and characterized using X-ray diffraction, optical microscopy, microhardness tester, Form Talysurf 50 surface profile, wear and friction measurements using oscillating ball-on-disk tribometer, contact angle analyzer for wettability measurements and Gill AC
instrument for corrosion measurements.
The current work is classified into two main groups of samples.
The first one was devoted to study the effect of applied power on the
mechanical, physical and electrochemical properties of Ti-Zr-N coatings, The composition and properties of Ti-Zr-N films were varied as the
applied power changing from 125 W up to 225 W at a fixed deposition time of 90 min and constant nitrogen / argon gas ratio of 20%. XRD analysis reveals that formation of FCC structure (Ti, Zr)N as a solid solution phase and TiN as a chemical compound phase. The dominant phase (Ti, Zr)N shows a preferred orientation in (111) direction. It has been found that all Ti-Zr-N coatings have a nano composite microstructure.High deposition rate of 0.58 nm/s was recorded for Ti-Zr-N films at applied power of 225 W.
The microhardness of the coating is increased up to 1000 HV0.025
which approximately represents 4-folds as that of AISI 304stainless steel substrate. Furthermore, the wear and corrosion resistance are improved for Ti-Zr-N films in comparison with AISI 304stainless steel substrate.The wear rate is improved from 66.64 mm3/Nm for AISI 304 substrate to 15.75 mm3/Nm after depositing Ti-Zr-N. Moreover, the friction coefficient decreases from nearly 0.69 for the austenitic substrate XIII to nearly 0.16 after coating. Finally, the corrosion resistance of Ti-Zr-N films has been improved about 1000 times as that of AISI 304 substrate.In the second group of samples, Ti-Zr-N films deposited on AISI 304 stainless steel substrate using pulsed magnetron sputtering technique at different N2 /Ar gas pressure ratios.The effects of N2 /Ar gas pressure ratio from 10% up to 50% N2 using 150 W at fixed operated time 90 min on the microstructure, mechanical, tribological and electrochemical properties of the Ti-Zr-N films were examined.The analysis of X-ray diffraction (XRD) indicated a formation of solid solution phase of (Ti-Zr)N with FCC structure and a chemical compound phase of TiN. The solid solution phase (Ti-Zr)N has the
preferred orientation (111). The microhardness of the coatings have high values with respect to the associated value of AISI 304 stainless steel substrate; up to 4-folds. Furthermore, the wear rate improves from 66.64 mm3/Nm for AISI substrate to 5.01 mm3/Nm after depositing Ti-Zr-N.The friction coefficient decreases from nearly 0.69 for the austenitic substrate to nearly 0.12 after coating with Ti-Zr-N. Moreover, it has been found that the corrosion resistance substantially improved (factor of 1000 times) after the coating.
1
1.1 General
Hard coating is a major member in the surface engineering family,
is frequently used to improve the functionality and the life time of a wide
variety of mechanical tools under high and constant wear loads. In the
materials engineering field, the affecting mechanisms involve both wear
and corrosion. Nowadays, the most widespread applications of hard
coatings are wear resistance and corrosion protection. There are several
ways of depositing thin film onto the surface of material, such as thermal
evaporation, chemical vapor deposition and physical vapor deposition
techniques. Among these, physical vapor deposition (PVD) has become a
well-developed method and a favored process in the coating techniques.
PVD deposition included several techniques such as sputtering
deposition, cathode arc deposition and electron beam deposition. The
most common method to produce hard coatings is considered by
sputtering process. Sputtering can be defined as the erosion of a solid
surface, commonly termed ”the target”, due to the ejection of material as
a result of energetic particle bombardment. The ejected material can be
deposited onto another surface intercepting its trajectory. The flexibility
and easy fabrication of diverse composite films are the advantages of
sputtering method. It is recently known that, Pulsed magnetron sputtering
(PMS) technique is an effective technique used for various coatings
preparation. The PMS process has become an excellent choice for the
deposition of metallic, low conductive materials and even insulator
materials for various industrial applications. PMS has low target
.