Basic concepts in Metallurgical Engineering Gate Mechanical Concepts
2. Gamma iron exists at temperatures between 910 oC and 1400 °C.
3. Ferromagnetic alpha iron exists in temperature ranges below 723°C.
4. Paramagnetic alpha iron changes to gamma iron at 910°C.
5. Fatigue failure: Fatigue failure occurs when a part is subjected to compressive stresses.
6. Homogeneous: A body with identical properties throughout
7. Elastic behavior : If a material recovers its original dimensions when the load is removed.
8. A ductile fracture is characterized by appreciable plastic deformation before crack propagation.
9. Resilience: The ability of a material to absorb energy when elastically deformed
10. The machining properties of steel can be improved by adding sulfur, lead and phosphorus.
11. Eutectoid steel the percentage of carbon is 0.8%.
12. A cold chisel is made of high-carbon steel.
13. An engineer's hammer is made of forged steel.
14. Cyanidation: The process of adding carbon and nitrogen by heat treating steel to increase its surface hardness.
15. The tensile strength of common cast iron varieties is in the range of 840-500 Mpa.
16. In carbon steel casting, the percentage of carbon is less than 1.7%.
17. Aluminum alloys for die casting must have considerable fluidity.
18. Electroforming is especially valuable for thin-walled parts that require high precision and internal surface finish.
19. In mechanical metallurgy, the process of heating cold-pressed metal is called sintering.
20. The hardness of steel increases if it contains martensite.
21. The presence of sulfur in pig iron makes smelting unsafe.
22. The compressive strength of gray cast iron in tonnes per square cm is in the order of 5-7.
23. The machinability of steel can be increased by phosphorus, lead and sulfur.
24. Steel with 0.8% carbon and 100% pearlite is known as eutectoid steel
25. The maximum hardenability of any steel depends on the carbon content.
26. In 18-4-1 high speed steel, the maximum percentage is iron.
27. In compression, a prism of brittle material will break in shear along an oblique plane.
28. The cast alloy contains nickel and molybdenum.
29. Cutting is a process associated with forging.
30. Adding lead and bishmuth to aluminum results in improved machinability
31. The smelting crucible is made of graphite.
32. Age hardening is related to duralumin.
33. For heavy loads on aircraft bearings malaria used with lead to reduce the risk of seizure is silver.
34. Compared to steel, the tensile strength of wood is generally 1/5.
35. The compressive strength of wood is generally greatest along the grain.
36. Superconducting properties exist at temperatures below 10 K.
37 . Weld deterioration: The phenomenon of weld deterioration is associated with stainless steels.
38. Bloom: Blooms are obtained by passing hot ingots through rolling mills and have sizes from 150 mm x 150 mm to 350 mm x 350 mm.
39. A knoop indenter is a diamond group for a pyramidal.
40. A unit cell that contains nine atoms is known as a body-centered cubic space lattice.
41. The commonly used process for thermoplastic materials is injection molding.
42. The most important element that controls the physical properties of steel is carbon.
43. In the annealing process, hypoeutectoid steel is heated below the A1 line with the aim of making the steel ductile for cold working.
44. The imperfection in the crystal structure of the metal is known as dislocation.
45. Polyesters belong to the group of thermosetting plastics.
46. The effect of alloying zinc with copper is to increase strength and ductility (if added up to 10-30%).
