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COBALT and ALLOYS by IAM,BZU multan PAKISTAN

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Arsalan Ahmad

Cobalt is a lustrous, silvery-blue metal that is extracted as a byproduct of nickel and copper refining. It forms alloys with other metals that have important applications. Cobalt alloys exhibit high strength and corrosion resistance and are used in jet engines, batteries, and medical tracers. Specific alloys include wear-resistant stellite, heat-resistant alloys containing chromium and tungsten, and corrosion-resistant alloys with nickel, chromium, and molybdenum.

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COBALT AND ALLOYS IJAZ AHMED MME-15-32 ARSALAN AHMAD MME-15-33 M.ASIF MME-15-34 M.SAMIUALLAH MME-15-35
COBALT and ALLOYS by IAM,BZU multan PAKISTAN
INTRODUCTION HISTORY PROPERTIES EXTRACTION ALLOYS & USES
Introduction: It was discovered by Swedish scientist Georg Brandt in1739. Cobalt word is derived from German word Kobald means evil sprits due to its color and blister appearance. Cobalt (Co) is a lustrous, silvery-blue, non-ferrous metal found in cobaltite, smaltite, and erythrite minerals. Important ore deposits are found in DR Congo, Canada, Australia, Zambia and Brazil. Most cobalt is formed as a by-product of nickel refining. Cobalt alloys are metal alloys containing cobalt as the base material.
Major Properties of Cobalt: Atomic number of cobalt is 27 and atomic mass 58.93 . Density of cobalt is 8.8 g/cm3. At temperatures below 417属C cobalt exhibits a hexagonal close-packed structure. The elastic modulus of cobalt is about 210 GPa (30 x 106 psi) in tension and about 183 GPa (26.5 x 106 psi) in compression. They exhibit high strength and toughness, excellent high temperature strength and resistance, and good corrosion resistance. Cobalt is a ferromagnetic material. Vanderwaals radius of cobalt is 0.125 nm. The metal has 12 radioactive isotopes, none of which occurs naturally.
Cobalt Base Alloys: Wear resistance alloys: Alloys are those that are made to resist abrasive wear, sliding wear, and erosive wear. They consist mostly of cobalt and chromium but may also contain tungsten or molybdenum and a small amount of carbon. Stellite is a name for this range of alloys trademarked by the Deloro Stellite Company. Chemical composition of Stellite alloys is approximately: Cr ~ 25-30% Mo = 1% max W = 2-15% C ~ 0.25-3.3% Fe = 3% max Ni = 3% max Si = 2% max Mn = 1% max. Co = rest of balance
Heat Resistance Alloys: Alloys are those that are made to resist elevated-temperature strength and resistance to thermal fatigue. Although they are not as widely used as nickel based high- temperature alloys. they play a role in temperatures above nickels deterioration point and in applications where sulfidation resistance is important. In general, cobalt-base high-temperature alloys have the following chemical composition: Cr = 20-23% W = 7-15% Ni = 10-22% Fe = 3% max C = 0.1-0.6% Co = rest of balance.
Corrosion Resistance Alloys: Alloys are those that are designed to resist aqueous corrosion. They are limited in their corrosion resistance in comparison to nickel-chromium-molybdenum alloys. However, several low-carbon, wrought cobalt-nickel- chromium-molybdenum alloys exist to satisfy the need for a corrosion resistant cobalt base alloy. Chemical composition of these alloys is: Cr = 20-25% W = 2% Mo = 5-10% Ni = 9-35% Fe = 3% max C = 0.8% max N = 0.1% max Co = rest of balance.
Extraction: It is mostly extracted as a by product of Ni ,Ag , Pb,Cu,Fe , like Monds process of Ni. It is also extracted from modified caron process. The whole process could be describe by the following flow sheet diagram.
COBALT and ALLOYS by IAM,BZU multan PAKISTAN
Uses: -Paint pigments. -Nickel-base superalloys. -Cemented carbides and tool steels. -Magnetic materials. -Artificial g-ray sources. -Cobalt is also used to make alloys for jet engines and gas turbines. -Cobalt is widely used in batteries and in electroplating. -Cobalt-60, a radioactive isotope of cobalt, is an important source of gamma rays and is used to treat some forms of cancer and as a medical tracer.

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COBALT and ALLOYS by IAM,BZU multan PAKISTAN

  • 1. COBALT AND ALLOYS IJAZ AHMED MME-15-32 ARSALAN AHMAD MME-15-33 M.ASIF MME-15-34 M.SAMIUALLAH MME-15-35
  • 4. Introduction: It was discovered by Swedish scientist Georg Brandt in1739. Cobalt word is derived from German word Kobald means evil sprits due to its color and blister appearance. Cobalt (Co) is a lustrous, silvery-blue, non-ferrous metal found in cobaltite, smaltite, and erythrite minerals. Important ore deposits are found in DR Congo, Canada, Australia, Zambia and Brazil. Most cobalt is formed as a by-product of nickel refining. Cobalt alloys are metal alloys containing cobalt as the base material.
  • 5. Major Properties of Cobalt: Atomic number of cobalt is 27 and atomic mass 58.93 . Density of cobalt is 8.8 g/cm3. At temperatures below 417属C cobalt exhibits a hexagonal close-packed structure. The elastic modulus of cobalt is about 210 GPa (30 x 106 psi) in tension and about 183 GPa (26.5 x 106 psi) in compression. They exhibit high strength and toughness, excellent high temperature strength and resistance, and good corrosion resistance. Cobalt is a ferromagnetic material. Vanderwaals radius of cobalt is 0.125 nm. The metal has 12 radioactive isotopes, none of which occurs naturally.
  • 6. Cobalt Base Alloys: Wear resistance alloys: Alloys are those that are made to resist abrasive wear, sliding wear, and erosive wear. They consist mostly of cobalt and chromium but may also contain tungsten or molybdenum and a small amount of carbon. Stellite is a name for this range of alloys trademarked by the Deloro Stellite Company. Chemical composition of Stellite alloys is approximately: Cr ~ 25-30% Mo = 1% max W = 2-15% C ~ 0.25-3.3% Fe = 3% max Ni = 3% max Si = 2% max Mn = 1% max. Co = rest of balance
  • 7. Heat Resistance Alloys: Alloys are those that are made to resist elevated-temperature strength and resistance to thermal fatigue. Although they are not as widely used as nickel based high- temperature alloys. they play a role in temperatures above nickels deterioration point and in applications where sulfidation resistance is important. In general, cobalt-base high-temperature alloys have the following chemical composition: Cr = 20-23% W = 7-15% Ni = 10-22% Fe = 3% max C = 0.1-0.6% Co = rest of balance.
  • 8. Corrosion Resistance Alloys: Alloys are those that are designed to resist aqueous corrosion. They are limited in their corrosion resistance in comparison to nickel-chromium-molybdenum alloys. However, several low-carbon, wrought cobalt-nickel- chromium-molybdenum alloys exist to satisfy the need for a corrosion resistant cobalt base alloy. Chemical composition of these alloys is: Cr = 20-25% W = 2% Mo = 5-10% Ni = 9-35% Fe = 3% max C = 0.8% max N = 0.1% max Co = rest of balance.
  • 9. Extraction: It is mostly extracted as a by product of Ni ,Ag , Pb,Cu,Fe , like Monds process of Ni. It is also extracted from modified caron process. The whole process could be describe by the following flow sheet diagram.
  • 11. Uses: -Paint pigments. -Nickel-base superalloys. -Cemented carbides and tool steels. -Magnetic materials. -Artificial g-ray sources. -Cobalt is also used to make alloys for jet engines and gas turbines. -Cobalt is widely used in batteries and in electroplating. -Cobalt-60, a radioactive isotope of cobalt, is an important source of gamma rays and is used to treat some forms of cancer and as a medical tracer.