Dr. B. Kiran Naik Project guide: Prof. Debasish Sarkar Department: Mechanical Engineering NIT Rourkela, Rourkela – 769008 (Odisha), India Date: 20/04/2022 Fortran Programming Introduction to Fortran Fortran Basics Variables and Data Types Arrays Control Structures Functions and Subroutines Input/Output Statements Fortran Examples Conclusion

1. Name: Vetchangi Gurunadh (Roll No: 118CR0122)
Course instructor: Prof. Debasish Sarkar
Subject: Tribology of materials (CR4102)
Department of Ceramic Engineering
NIT Rourkela, Rourkela – 769008 (Odisha), India
Tribological study of ZTA

2. Contents 01
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory
 Introduction
 Fracture toughness of ZTA
 Features of ZTA
 Application limitations of ZTA
 Zirconia ceramics
 Different phases of Alumina and Zirconia
 Zirconia ceramics – monoclinic phase structure

3. Introduction of ZTA 02
 The zirconia toughened alumina have different type of attractive properties, including high temperature
mechanical strength, good thermal shock resistance, wear, and oxidation resistance, and low thermal
conductivity and corrosion resistance.
 This makes ZTA ceramics suitable for different challenging applications. like bearing components ( ball,
roller, raceways ). Cutting tools, inserts ( replacing carbide and metal tools ). Electrosurgical insulators,
valves seats pump components, oxygen sensors, dies, and Biomedical Applications.
 The presence of stabilized Zirconia in ZTA composite plays a significant role in the improvement of
toughness by stress-induced transformation toughening and microcrack toughening mechanism.
 The wear of alumina like all the other ceramics considered for resistant application may be divided into
well defined mild and severe wear zone with a narrow transition before mild to severe.

4. Introduction of ZTA 03
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory
Fig.1. Zirconia Toughened Alumina (ZTA)
Ceramic tube
 The advantage of Zirconia toughened alumina is additional strength and
toughness over alumina with lower cost than Zirconia. ZTA ceramics are used widely
in applications where strength, toughness, chemical inertness, and wear
 The combination of Alumina oxide and 10 – 20 % Zirconium oxide provide
much higher strength toughness, hardness, and wear resistance than alumina alone.
 Wear properties of alumina and ceramics are also a function of different parameters
test conditions such as sliding distance, surface condition, and velocity

5. 04
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory
Fig.2. Zirconia Toughened Alumina
(ZTA) Ceramic powder
 This process is called transformation toughening is the phenomenon that increases
the fracture toughness of ZTA.
 The zirconia particle changes the crystal structure from a tetragonal to monoclinic
structure, causing a volume expansion that compresses the surrounding crack in the
alumina matrix.
 ZTA should be considered for any application where structural strength is needed
 that exceeds the standard alumina properties.

6. 05

7. fracture toughness of ZTA 06
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory
 Zirconia Toughened Alumina ( ZTA ) one of the most successful commercial ceramic-based cutting tool
insert which is fully utilized the advantage of Zirconia.
 The fracture toughness of composition material is generally low because dislocation motion extremely
limited due to the nature of chemical bonds which are ionic or covalent.
 Alumina has mixed ionic and covalent bonding with a very high enthalpy of formation.
 The problem of low fracture toughness in ceramics can be overcome by designing and preparation
composite material reinforced with fibers, whiskers.
 The strongest atomic bonding and hexagonal structure make the dislocation motion
very difficult in Alumina.
 The use of Zro2 based ceramics is one of the possible alternatives to circumvent the limitation
of low fracture toughness.

8. 07
 The stable modification of Al2o3 the application cutting tool inserts working under the mechanical
loads and thermal conditions are limited due to their brittleness and low strength.
 To overcome the brittleness, reinforcement such as yttria-stabilized zirconia(YCZ ) is introduced in
Al2o3 producing Zirconia Toughened Alumina ( ZTA ).
 YSZ increased the toughness by transforming the phase from t - Zro2 to m - Zro2.
 In order to vary the ratio of m – Zro2 to t – Zro2 in Zro2 toughened Al2o3 without influencing the
size and volume fraction of the Zro2 particles.
 Y2o3 was incorporated as a stabilizing agent so that was the driving force for the transformation from t- Zro2 to m-Zro2.
 Al2o3 can be toughened dispersed by Zro2 particles (ZTA) toughness increments have been observed both tetragonal
Zro2.

9. Features of ZTA
08
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory
 It has a higher strength than Alumina.
 Lower cost than Zirconia.
 High corrosion resistance.
 High erosion resistance.
 High fracture toughness.
 It has capable of a very fine surface finish.

10. 09
Application limitations of ZTA
 ZTA does provide higher strength than Alumina.
 But the temperature limitations of 1500◦c (2732)F must be observed.
 Above the temperature the strength reduce the contribution of the Zirconia reduced.
 Use in the most environment at a temperature above 250◦c also must be careful as the Zirconia is
subjected
temperature degradation.

11. Typical applications of ZTA 10
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory
 The structural material and tribological applications of alumina are most important.
 Thread guides in the textile industry.
 Spray nozzles for sand and hot blasting.
 Rollers end other supports for the paper industry.
 Extrusion dies.
 Automobiles pump seals.

12. Zirconia Ceramics
11
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory
Zirconia Ceramics (Roll No.:118CR0122)
 Interest in zirconia ceramics.
 High toughness
 Very low thermal conductivity → thermal barrier coatings in jet engines.
 High refractive index → cheap substitute for diamond jewelry
 Zirconia occurs naturally as the mineral baddeleyite mainly in South Africa.
 However, the main source of zirconia is zircon sand (ZrSiO4) in the beach sands in India, Australia, and
the United States.

13. Different phases of Alumina and Zirconia 12
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory
 t →m phase transformation is accompanied by a volume increase of 4-6% and a shear strain of about 1-
2%.
 → A pure zirconia body disintegrates on cooling after sintering.
 → Pure zirconia can not be used as a sintered part in the pure form.
a) Alumina b) Zirconia c) Zirconia toughened Alumina femoral head components

14. Different phases of Alumina and Zirconia
13
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory
 The Zirconia Toughened Alumina ( ZTA).The microstructure contains different phases
 The ZTA depend on the Purity and Microstructure.
 This are alumina, zirconia, and Zirconia Toughened Alumina (ZTA)
 Alumina ceramic composite with oldest history of use in orthopaedic implants.
 Zirconia ceramics was initially chosen for commercialization largely due to its larger
strength relative to Zirconia.
 Zirconia particles are finely distributed in a stable alumina matrix will change phase
from tetragonal to monoclinic.
 The new ceramics Zirconia Toughened Alumina (ZTA) Alumina consist 75 % and Zirconia
25% with no presence of mixed oxides.

15. Zirconia ceramics – Monoclinic phase structure
14
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory

16. 19
Course instructor: Dr. B. Kiran Naik
ME3071: Basic Mechanical Engineering Laboratory
Project title: Fortran; (Roll No.:118ME0480)