Nickel and its alloys, as well as titanium and its alloys, are important engineering materials. Nickel is a silvery white metal that is magnetic, hard, and ductile. It has many applications as an alloying element to produce alloys like Inconel and Hastelloy that are heat and corrosion resistant. Titanium is a strong yet lightweight metal that is highly corrosion resistant. It is commonly extracted from ores using the Kroll process and made into alpha, beta, and alpha-beta alloys for diverse applications like aerospace, industrial, automotive, and medical implants.

1. ENGINEERING MATERIALS NICKEL AND ITS ALLOYS TITANIUM AND ITS ALLOYS

2. NICKEL

3. PHYSICAL PROPERTIES SILVERY WHITE METAL HARD AND DUCTILE MAGNETIC UPTO 355 DEGREE CELSIUS FCC WITH LATTICE PARAMETER OF 0.352 NM AND ATOMIC RADIUS OF 0.124 NM MELTING PT. = 1728K HEAT OF FUSION = 17.48 KJ/MOLE

4. MECHANICAL PROPERTIES THERMAL CONDUCTIVITY = 90.9 W/M/K YOUNG'S MODULUS = 200 GPa SHEAR MODULUS = 76 GPa BULK MODULUS = 180 GPa POISSON'S RATIO = 0.31

5. OCCURENCE LATERITE ORES : (Fe, Ni)O(OH) GARNIERITE ORES : (a hydrous nickel silicate): (Ni, Mg) 3 Si 2 O 5 (OH) 4 PENTLANDITE ORES : Ni, Fe)9S8 ABOUT 40% FROM RUSSIA AND 30% FROM CANADA

6. EXTRACTION AND PURIFICATION Commercial extraction is from sulphide ores. Nickel is recovered through extractive metallurgy . Concentration is done by froth floatation Next stage is roasting and reduction of the sulphide ore which yields 75% pure nickel Refining is done by “Monds Process” Nickel is reacted with carbon monoxide at around 50 °C to form volatile nickel carbonyl . Any impurities remain solid while the nickel carbonyl gas passes into a large chamber at high temperatures in which tens of thousands of nickel spheres, called pellets, are constantly stirred. The nickel carbonyl decomposes, depositing pure nickel onto the nickel spheres. Alternatively, the nickel carbonyl may be decomposed in a smaller chamber at 230 °C to create fine nickel powder. The resultant carbon monoxide is re-circulated through the process. The highly pure nickel produced by this process is known as carbonyl nickel.

7. APPLICATIONS Household : Magnets, Coins, Rechargeable cells, Electric guitar strings Industrial : Alloys, Wires, electric gadgets. Laboratory: Catalyst for hydrogenation Biology : Present in enzymes

8. NICKEL ALLOYS

9. ALNICO “ ALNICO” = Al + Ni+ Co + Cu(traces) + Ti (traces) + Fe It is ferromagnetic and used in permanent magnets 8–12% Al, 15–26% Ni, 5–24% Co6% Cu, up to 1% Ti and balance is Fe.

10. GERMAN SILVER Cu + Ni + Zn 60% copper, 20% nickel and 20% zinc. Applications : silver plated cutlery zippers & jewellery musical instruments pipe fittings

11. INCONEL Family of austenitic nickel - chromium based superalloys PROPERTIES: Oxidation & corrosion resistent High heat resistence Difficult to machine APPLICATIONS : Gas turbine combustors and blades. Shafts Rocket skins.

12. MONEL METAL COMPOSITION : nickel (up to 67%) and copper , with some iron and other trace elements PROPERTIES : difficult to machine highly corrosion resistent highly sonorous APPLICATIONS: submerged pumpsets musical instruments oilfield industry earth moving drills lab apparatus

13. NICHROME 80% nickel and 20% chromium PROPERTIES: high melting point high electrical resistivity good stability from deforming APPLICATIONS: resistance heating coils rocket igniters jewellery casting supports ceramic manufacturing industry

14. HASTELLOY COMPOSITION : Nickel + molybdenum + chromium PROPERTIES : High wear resistence high corrosion resistance high stress service TYPES : A,B,C,D & its variants APPLICATIONS : Bearings, pressure vessel linings, chemical reactor pipes....

15. MU-METAL 75% nickel , 15% iron , plus copper and molybdenum PROPERTIES : very high magnetic permeability low hysteresis loss. more ductile and workable. APPLICATION: Electric power Hard Drives Cathode-ray tubes Magnetic phonograph cartridges Magnetic resonance imaging The magnetometers used in magnetoencephalography and magnetocardiography Photomultiplier Vacuum chambers Superconducting

16. TITANIUM

17. PHYSICAL PROPERTIES Low density high strength and ductility lustrous corrosion resistant and high melting point low thermal & electrical conductivity Paramagnetic

18. MECHANICAL PROPERTIES Young's modulus = 116 Gpa Shear modulus 44 Gpa Bulk modulus 110 Gpa Poisson ratio 0.32 Thermal conductivity = 21.9 W/m/K

19. OCCURENCE Titanium is always bonded to other elements in nature It is present in most igneous rocks and in sediments derived from them living things and natural bodies of water Titanium is contained in meteorites found in coal ash Major ores : anatase,brookite,ilmenite,rutile,titanite,perovs-kite and a few iron ores.

20. EXTRACTION AND PRODUCTION 4 MAJOR STEPS : - reduction of titanium ore into "sponge" melting of sponge, or sponge plus a master alloy to form an ingot primary fabrication, where an ingot is converted into general mill products such as billet, bar, plate, sheet, strip, and tube secondary fabrication of finished shapes from mill products KROLL'S PROCESS ( COMMERCIAL PROCESS) : - 2 FeTiO 3 + 7 Cl 2 + 6 C -> 2 TiCl 4 + 2 FeCl 3 + 6 CSSO (900 °C) TiCl 4 + 2 Mg -> 2 MgCl 2 + Ti (1100 °C)

21. APPLICATIONS ALLOYING PAINTS,PAPER,TOOTHPASTE,PLASTICS CORROSION RESISTANT TOOLS SURGICAL INSTRUMENTS AIRCRAFT PARTS AND GEARS MARINE VEHICLE PARTS PLUMBING EQUIPENTS TiCl 4 IS USED TO PRODUCE MANY CATALYSTS. SPORTS GOODS DEGIGNER JEWELLERY ORTHOPAEDIC IMPLANTS

22. TITANIUM ALLOYS The crystal structure of titanium at ambient temperature and pressure is close-packed hexagonal α phase . At about 890°C, the titanium undergoes an allotropic transformation to a body-centred cubic β phase which remains stable to the melting temperature. Some alloying elements raise the alpha-to-beta transition temperature (i.e. alpha stabilizers) while others lower the transition temperature (i.e. beta stabilizers). Aluminium, gallium, germanium, carbon, oxygen and nitrogen are alpha stabilizers. Molybdenum, vanadium, tantalum, niobium, manganese, iron,chromium, cobalt, nickel ,copper and silicon are beta stabilizers.

23. CATEGORIES Alpha alloys which contain neutral alloying elements (such as tin ) and/ or alpha stabilisers (such as aluminium or oxygen ) only. These are not heat treatable. Near-alpha alloys contain small amount of ductile beta-phase. Besides alpha-phase stabilisers, near-alpha alloys are alloyed with 1-2% of beta phase stabilizers such as molybdenum , silicon or vanadium. Alpha & Beta Alloys , which are metastable and generally include some combination of both alpha and beta stabilisers, and which can be heat treated. Beta Alloys , which are metastable and which contain sufficient beta stabilisers (such as molybdenum, silicon and vanadium to allow them to maintain the beta phase when quenched, and which can also be solution treated and aged to improve strength.

24. GENERAL PROPERTIES OF TITANIUM ALLOYS It is stronger than steel, but 45% lighter It is not easily corroded resistance to high temperatures low thermal conductivity low electrical conductivity heat has no or negligible effect on dimension but it hardens on heating higher resistance towards metal fatigue no harm to biological tissues

25. ALLOY GRADES BY VARYING THE TYPE AND COMPOSITION OF METALS ADDED, 38 DIFFERENT ALLOYS ARE USED FOR COMMERCIAL PURPOSES. MAJOR ALLOYED METALS ARE ALUMINIUM, VANADIUM, CHROMIUM AND MOLYDENUM. THESE ARE VERY VERY COSTLY ALLOYS.

26. Aerospace Applications turbines shafts sheet metal work

27. Industrial Applications Increased life of articles. Reliability of machine parts Pipings

28. AUTOMOTIVE Engine parts such as connecting rods, wrist pins, valves, valve retainers and springs, rocker arms and camshafts, to name a few, lend themselves to fabrication from titanium, because it is durable, strong, lightweight and resists heat and corrosion.

29. Computer Industry Modern Hard disks Modern pendrives

30. Human Implants Surgical instruments Implants to repair facture of bones...