Why do mechanical and physical properties depend on the density of PM parts?
Explain why the mechanical and physical properties depend on their density. Mechanical properties rely on their density to maximize metal particle contact and cohesion which affects a metal’s strength, ductility, elastic modulus, and toughness. Describe the relative advantage of cold isostatic pressing.
What is the purpose of sintering?
Sintering is a heat treatment commonly used to increase the strength and structural integrity of a given material. Powder metallurgy processes use sintering to convert metal powders and other unique materials into end-use parts.
What is Powder Metallurgy explain the process with the help of a flow chart?
The powder-metallurgy (PM) process, depicted in the diagram below, involves mixing elemental or alloy powders, compacting the mixture in a die, and then sintering, or heating, the resultant shapes in an atmosphere-controlled furnace to metallurgically bond the particles.
What are the applications of powder metallurgy?
18.3. Production of powder metallurgy biomaterials
- Metal injection moulding.
- Pressing, green machining and sintering.
- Replica method.
- Selective laser melting/electron beam melting.
- Self-propagating high-temperature synthesis of porous NiTi.
- Porous coatings.
What are the limitations of powder metallurgy?
Limitations:
- High cost of metal powders compared to the cost of raw material used for casting or forging a component.
- High cost of tooling and equipment.
- Large or complex shaped parts are difficult to produce by PM process.
- Parts have lower ductility and strength than those produced by forging.
What are the limitations of forged steel?
Disadvantages of Forging: Lack of control over microstructure. Greater need for secondary machining, which adds to the project’s cost and lead time. Cannot produce porous bearings, sintered carbides, or parts with a mix of multiple metals. Cannot produce small, finely designed parts without machining.
What are the limitations of forging?
The main disadvantages of forging are:
- The secondary finishing process requires.
- The size might be limited because of the press size.
- The maintenance cost is high.
- The metals gots distorted if works below the required temperature.
- The initial cost is high.
- Some material can not be forged in the forging process.
Which is stronger cast or forged steel?
Forged steel is generally stronger and more reliable than castings and plate steel due to the fact that the grain flows of the steel are altered, conforming to the shape of the part. The advantages of forging include: Generally tougher than alternatives. Will handle impact better than castings.
What is difference between hot and cold working?
Forming is the metalworking process of fashioning metal parts and objects through mechanical deformation. Hot Working is done at temperatures above the recrystallization temperature of the metal, and Cold Working is done at temperatures below the recrystallization temperature of the metal.
How do you increase ductility of a structure?
Lateral reinforcement tends to improve ductility by preventing premature shear failures and by confining the compression zone, thus increasing deformation capability of a reinforced concrete beam. Ductility can be increased by • Decrease in the % tension steel (pt).
What is difference between creep and fatigue?
Creep And Fatigue are the phenomenon that lead to deformation and eventually failure of Components. Fatigue is a situation in which component is subjected to cyclic loading. Creep is a situation in which a component experiences deformation under constant load with time as it is put into use.
What is creep fatigue?
Creep: Progressive deformation of a material at constant stress. Fatigue: Deformation of a material at repeated stresses. Creep- Fatigue Interaction: Deformation of a material under repeated stresses at high temperature.