Alloys
- What does the Gibbs phase rule state and what does F = C − P + 2 mean? In one line The Gibbs phase rule states that for a heterogeneous system in equilibrium, not influenced by gravity, electric or magnetic forc... 1
- Why do we make alloys instead of using pure metals in engineering? In one line Alloys are made to improve properties of a pure metal, such as hardness, strength, corrosion resistance, melting point, castabil... 1
- What is a phase in the phase rule, and how do you count phases in a system? In one line A phase is any homogeneous, physically distinct and mechanically separable part of a system, separated from other parts by a def... 1
- What is a component in the phase rule, and how do you find the number of components? In one line The number of components is the smallest number of independently variable chemical constituents by which the composition of ever... 1
- What are degrees of freedom in the phase rule, and what do invariant and univariant systems mean? In one line Degrees of freedom (F) are the minimum number of independent variables, such as temperature, pressure and concentration, that mu... 1
- What is the reduced (condensed) phase rule and why is it used for alloy systems? In one line For solid–liquid (condensed) systems where the vapour phase is negligible and experiments are done at constant atmospheric press... 1
- How does Pattinson's process use the Pb–Ag phase diagram to desilverise lead? In one line Pattinson's process enriches silver from argentiferous lead (lead with a very small silver content) by cooling the melt so that... 1
- How do you read the lead–silver phase diagram and what happens at its eutectic point? In one line The Pb–Ag system is a two-component simple eutectic system whose temperature–composition diagram shows two freezing-point curves... 1
- How do you solve phase rule numericals to find phases, components and degrees of freedom? In one line Phase rule numericals are solved by carefully counting P and C for the given equilibrium and then applying F = C − P + 2 (or F′... 1
- What are the merits and limitations of the Gibbs phase rule? In one line The phase rule is a simple, general way to classify and predict equilibrium behaviour of heterogeneous systems, but it only appl... 1
- An alloy of Cd and Bi contain 25% of Cd Find the mass of eutectic in 1kg of solid Alloy, if the eutectic contains 40 % of Cd. Given: the alloy has 25% Cd (75% Bi), and the eutectic has 40% Cd (60% Bi). The alloy has less Cd (25%) than the eutectic (40%), so it has e... 1
- Why are alloys preferred over pure metals in many applications? Pure metals are generally soft, ductile, of low strength, easily corroded and hard to cast. Alloying improves these properties, so alloys ar... 1
- What is condensed phase rule equation? Write merits and limitation of phase rule. Condensed (reduced) phase rule: the phase rule is F = C − P + 2. For solid–liquid equilibria such as alloys, the vapour phase is practically... 1
- Explain the terms involved in Gibbs phase rule with an example of a one-component system. (Phase, Component and Degree of Freedom) Gibbs phase rule: F = C − P + 2 Phase (P): a homogeneous, physically distinct and mechanically separable part of a heterogeneous system, sep... 1
- Write notes on (a) reduced phase rule (c) applications of phase diagram. (a) Reduced (condensed) phase rule The Gibbs phase rule is F = C − P + 2. In solid–liquid systems (alloys) the gas phase is absent or neglig... 1
- An alloy of Cd and Bi contains 25% Cd. Find the mass of eutectic in 1 kg of alloy if the system contains 40% Cd. Given: the alloy has 25% Cd (75% Bi). "The system contains 40% Cd" is taken to mean that the eutectic contains 40% Cd (60% Bi), as in the st... 1
- What is condensed phase rule equation? Explain its application with the help of phase diagram to two component lead-silver system. Condensed (reduced) phase rule: Gibbs' phase rule is F = C − P + 2. In solid–liquid systems such as alloys the vapour phase is negligible, a... 1
- An alloy of tin and lead contain 73% tin. Find the mass of eutectic in 1kg of solid Alloy, if the eutectic contains 64% of tin. Given: the alloy has 73% Sn (27% Pb), and the eutectic has 64% Sn (36% Pb). The alloy has more Sn (73%) than the eutectic (64%). On cooling,... 1
- Give the purposes of making of an alloy. Alloys are made in order to: Increase hardness and strength. Pure metals are soft. Example: adding C to Fe gives steel; adding Cu to Au make... 1