What do solid arrows represent in the transformation of Fe-C alloys?
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Transformations involving diffusion.
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What do solid arrows represent in the transformation of Fe-C alloys?
Transformations involving diffusion.
Can you give examples of metastable phases?
Diamond and Cementite.
What happens to the lead-tin alloy as it cools from the liquid-phase region?
It undergoes microstructure development.
What is the composition of the lead-tin alloy mentioned?
C2.
What is the composition of the alloy discussed in the microstructure development?
35% wt Ni – 65% wt Cu.
What is the composition of a lead-tin alloy at eutectic composition?
C3.
What is the composition of the lead-tin alloy mentioned?
Eutectic composition C 3.
What occurs at the invariant point E in a phase diagram?
A eutectoid reaction takes place.
What are the two phases present in the Ni-Cu alloy at point B?
Liquid and solid α phases (solid solution of Ni-Cu).
What is martensite?
An extremely hard and brittle phase in iron-carbon alloys.
What are the two types of cooling curves shown in the continuous cooling transformation diagram?
Moderately rapid and slow cooling curves.
What is the shape of Bainite particles?
Elongated and needle-shaped particles of Fe3C in a ferrite matrix.
What happens during a eutectic reaction?
An alloy of composition C_E undergoes a reaction when heated or cooled through the eutectic temperature (T_E).
What is the significance of the temperature 248°C in the Magnesium-Lead phase diagram?
It indicates a specific phase transition or reaction point in the alloy system.
What is the significance of the isothermal transformation in Fe-C alloys?
It helps in understanding the transformation of phases during cooling or heating at a fixed temperature.
What mechanical properties are analyzed for Fe-C alloys?
Brinell hardness, tensile strength, and ductility (%RA).
What does the Copper-Silver phase diagram illustrate?
The phases and phase relationships of copper and silver alloys at various temperatures and compositions.
What does 'W L' signify in the context of the Cu-Ni phase diagram?
It represents a liquid phase in the diagram.
What is the significance of T_E in phase diagrams?
It is the temperature at which the phases begin to coexist.
What is the microstructure of pure iron at 90x magnification?
α-ferrite.
What is the composition of the lead-tin alloy mentioned?
C1.
What is the first phase to solidify in the alloy?
46 wt % Ni.
Which phase diagram is associated with copper and zinc?
Copper-Zinc phase diagram.
How does carbon content influence the DBTT of plain carbon steels?
Higher carbon content typically lowers the DBTT, making the steel more ductile at lower temperatures.
What is the significance of the eutectic temperature in lead-tin alloys?
It defines the temperature at which the alloy has a specific microstructure.
What are the characteristics of spheroidite?
Spherelike particles of Fe₃C embedded in a ferrite matrix.
What does the continuous cooling transformation diagram for a eutectoid iron-carbon alloy illustrate?
The dependence of the final microstructure on the transformations that occur during cooling.
What does Wα represent in phase diagram calculations?
The weight fraction of phase α.
What is the eutectic temperature (T_E)?
The temperature at which a eutectic reaction occurs.
What does a continuous-cooling transformation diagram illustrate?
The phase changes of an alloy steel as it cools continuously.
What is the carbon content range for pure iron?
0 - 0.008 wt%C.
How does tempering affect the hardness of martensitic steel?
Tempering generally reduces hardness compared to untempered martensitic steel.
What is free energy?
A thermodynamic quantity that is minimized in a system at equilibrium.
What does the term 'microstructure' refer to in the context of alloys?
The arrangement and organization of phases within the alloy at a microscopic level.
What does the term 'microstructure' refer to in the context of alloys?
The arrangement and distribution of phases within the alloy.
What is a peritectic reaction?
An invariant reaction involving three phases at equilibrium.
What does a continuous cooling transformation diagram represent for Fe-C alloys?
It shows the phase transformations that occur in iron-carbon alloys during continuous cooling.
What type of transformation occurs in Fe-C alloys?
Phase transformation.
What effect does tempering have on martensite?
It increases ductility at the expense of strength and hardness.
What is the significance of understanding DBTT in Fe-C alloys?
It helps predict the performance of steels under varying temperature conditions.
Which countries are mentioned in relation to the 4340 steel?
USA, Britain, and Japan.
What microstructure is formed in the Fe-C system at eutectoid composition?
Pearlite.
What is Eutectoid ferrite?
Ferrite that is presented in the pearlite.
What happens to ductility when solid solution strengthening occurs?
Ductility decreases.
How does ductility (%RA) change with tempering temperature in oil-quenched alloy steel 4340?
Ductility (%RA) increases with higher tempering temperatures.
What is Pearlite in the context of the Fe-C system?
A eutectoid microstructure consisting of alternating layers of ferrite and cementite.
How can the Magnesium-Lead phase diagram be used in metallurgy?
To determine the phases present at various temperatures and compositions, aiding in alloy design and processing.
What is the eutectoid composition in the Fe-C system?
0.76% wt C.
What microstructure is formed at the eutectoid composition in the Fe-C system?
Pearlite.
What does DBTT stand for in the context of plain carbon steels?
Ductile-to-Brittle Transition Temperature.
What is the duration for holding at 1000 seconds?
1000 seconds.
What is the relationship between hardness and carbon concentration in plain carbon steels?
Hardness increases with carbon concentration.
What is isothermal transformation in Fe-C alloys?
A phase transformation that occurs at a constant temperature.
What information can be derived from a phase diagram?
The phases present, their compositions, and the conditions under which they exist.
What does a phase diagram represent?
It shows the phases and their boundaries in terms of temperature and overall composition.
What is phase transformation in metals?
The process where metals change from one phase to another due to temperature or composition changes.
What does the notation 'S R' refer to in the Cu-Ni phase diagram?
It typically refers to a solid phase in the diagram.
What is the significance of the TTT diagram in isothermal transformations?
It illustrates the time-temperature-transformation relationships for phase changes.
What occurs under the solidus line in a binary isomorphous system?
The system consists of only one phase: the α phase.
What type of solution exists in the copper-nickel system?
A solid solution exists over all compositions.
How does temperature affect the phases in the Fe-C alloy?
Different temperatures lead to different phase transformations and microstructures.
What is the microstructure of pure iron at 325x magnification?
Austenite.
What type of alloy is a lead-tin alloy of eutectic composition?
A eutectic alloy.
What is the significance of T Eu in Fe-C alloys?
It is the eutectoid temperature where phase transformation occurs.
What happens to the microstructure of a lead-tin alloy at the eutectic temperature?
It changes above and below the eutectic temperature.
What temperature range is typically used to temper martensite?
Approximately 250 - 650 °C.
What is the composition of the Ni-Cu alloy at point B in terms of weight percentage?
35% Ni and 65% Cu.
What phases are present in the Cu-Ni alloy at equilibrium?
Liquid phase (20% Ni - 80% Cu) and α phase (37% Ni - 63% Cu).
What is the time taken to rapidly decrease temperature?
0.2 seconds.
What is the significance of the temperature in spheroidite formation?
It must be below the eutectoid temperature.
What is the relationship between microstructures and mechanical properties in iron-carbon alloys?
Microstructures influence the mechanical properties such as strength, ductility, and hardness in iron-carbon alloys.
What is the composition of eutectoid in the Fe-C system?
Fe₃C.
How does heat treatment affect metal alloys?
Heat treatment alters the microstructure and mechanical properties of metal alloys.
At what temperature does melting occur for the Cu-Ni alloy system?
Melting temperatures vary depending on the composition of the alloy.
What phases can form during isothermal transformation in Fe-C alloys?
Pearlite, bainite, and martensite.
What does the term 'Eutectoid' refer to?
A composition where a solid phase transforms into two other solid phases at a specific temperature.
What is a eutectoid reaction?
A solid transforms into other solid phases.
What are the three regions where two phases are in equilibrium in the Cu-Ag phase diagram?
α + β, α + L, and β + L.
What defines a hypoeutectoid alloy in the iron-carbon system?
An alloy with 0.022 - 0.76 wt % C.
At what temperature range does Bainite form?
Approximately 215 - 540 °C.
What does the Cu-Ni phase diagram represent?
The phase relationships between copper (Cu) and nickel (Ni) at various temperatures and compositions.
What is martensite?
A phase formed when austenite is rapidly cooled (quenched) to a relatively low temperature.
What type of steel is characterized by high hardness at room temperature?
Martensitic steel.
What is the significance of the phases in the Ni-Cu alloy?
They determine the mechanical properties and behavior of the alloy.
What does Lever's rule relate to in a mixture?
It relates the forces or weights of different phases in a mixture.
What is the initial temperature in the provided data?
T room (room temperature).
What is the shape of martensite grains?
Needle-shaped grains.
What phase is indicated by the letter 'M' in the isothermal transformation diagram?
Martensite.
What does an isothermal transformation diagram illustrate for a eutectoid Fe-C alloy?
It shows the phases and microstructural changes at constant temperature.
What phase does pure iron normally consist of?
α-ferrite phase.
What is the hardness characteristic of pearlitic steel compared to martensitic steel?
Pearlitic steel typically has lower hardness than martensitic steel.
What type of alloy is involved in the formation of martensite?
Iron-carbon (Fe-C) alloy.
What is coarse pearlite?
A microstructure formed in Fe-C alloys at temperatures just below the eutectoid temperature (T Eu).
What temperature range is fine pearlite formed at?
Around 540 °C.
What is the solid solubility limit for Ag in Cu at 779 °C?
CαE = 8 % wt Ag.
What is the last phase to solidify in the alloy?
Less than 35 wt % Ni.
What does the eutectic isotherm represent?
The lowest temperature at which liquid phase may exist at equilibrium.
What is the carbon content range for hypereutectoid composition?
Between 0.76 and 2.14 % wt C.
What type of alloy is specifically mentioned in relation to the continuous cooling transformation diagram?
Eutectoid iron-carbon alloy.
What happens to tensile strength when solid solution strengthening occurs?
Tensile strength increases.
What is the significance of the isothermal transformation in Fe-C alloys?
It helps in understanding how the microstructure evolves during heat treatment.
What is the tempering temperature mentioned for tempered martensitic steel?
371 °C (700 °F).
What is the primary phase transformation associated with Bainite?
Phase transformation in Fe-C alloy.
In Lever's rule, what does F represent?
Force or weight.
What is the duration of the first hold in the temperature profile?
20 seconds.
What is the term for the phase that forms before the eutectoid transformation in hypereutectoid steels?
Proeutectoid Fe₃C.
What is Proeutectoid cementite?
Cementite that is formed above the eutectoid temperature.
What do dashed arrows indicate in the transformation of Fe-C alloys?
Diffusionless transformations.
What is the eutectoid composition in the iron-carbon system?
0.76 wt % C.
What is the duration for holding in case (c)?
20 seconds.
What does the composition of phases in a phase diagram indicate?
The percentage or fraction of each phase present.
What does the letter 'A' represent in the isothermal transformation diagram for alloy steel 4340?
Austenite.
What is the time taken to decrease temperature in 0.3 seconds?
0.3 seconds.
What is Pearlite in the iron-carbon system?
A microstructure consisting of alternating layers or lamellae of α-Fe and Fe3C.
Rank the hardness of the following phases from hardest to softest: martensite, tempered martensite, lower bainite, upper bainite, fine pearlite, coarse pearlite, spheroidite.
Martensite > Tempered martensite > Lower bainite > Upper bainite > Fine pearlite > Coarse pearlite > Spheroidite.
What is the relationship between tempering temperature and yield strength in oil-quenched alloy steel 4340?
Yield strength changes with tempering temperature.
What is the composition of the liquid phase in the Cu-Ni alloy?
20% Ni and 80% Cu.
What is a solid solution?
A solid phase that contains a mixture of more than one element, with a uniform composition throughout.
At what temperature does the first solid phase form in a 50% wt Ni – 50% wt Cu alloy when cooled from 1400 °C to 1200 °C?
The first solid phase forms at the temperature indicated by the phase diagram for the alloy.
What do superimposed cooling curves on the diagram demonstrate?
The relationship between cooling rates and resulting microstructures.
What is the primary focus of the mechanical behavior of Fe-C alloys?
The study of how iron-carbon alloys respond to applied forces and stresses.
What is a metastable phase?
A phase or system existing at an energy level above that of a more stable state, requiring a small amount of energy to transition to the more stable state.
What is the structure associated with Fe-C alloys mentioned in the text?
Body centered tetragonal (BCT) structure.
What are the three phases present in a binary system phase diagram?
Solid, liquid, and gas.
What is a binary eutectic system?
A system of binary mixture that has a eutectic change.
What defines a hypereutectoid alloy in the iron-carbon system?
An alloy with 0.76 - 2.14 wt % C.
What are the two types of phases mentioned in the context of solidification?
Cored vs Equilibrium Phases.
What does the isothermal transformation phase diagram of Fe-C alloy illustrate?
The changes in phases of iron-carbon alloys at constant temperature.
What is a binary isomorphous system?
A system of 2 components that has complete solubility in solid and liquid phases.
At what temperature is austenite typically quenched to form martensite?
Around room temperature.
Give an example of a binary isomorphous system.
The Ni-Cu system.
What type of alloy is mentioned?
Iron-carbon alloy.
What are the key phases represented in the Fe-C isothermal transformation diagram?
Austenite, ferrite, cementite, and pearlite.
How does isothermal transformation temperature affect Brinell hardness and tensile strength in eutectoid Fe-C alloys?
Brinell hardness and tensile strength vary as a function of isothermal transformation temperature.
What is the composition of the lead-tin alloy mentioned?
C4.
What are the three single phases in the Cu-Ag phase diagram?
α (Cu rich), β (Ag rich), and L (liquid).
What is required to induce a transition from a metastable state?
The addition of a small amount of energy.
What is spheroidite?
A microstructure formed by heating pearlite or bainite to a temperature below eutectoid for a sufficiently long period of time.
What is the temperature at point B for the Ni-Cu alloy?
1,250 °C.
What type of phase diagram is used for H2O?
Pressure-temperature phase diagram.
What is the relationship between tempering temperature and tensile strength in oil-quenched alloy steel 4340?
Tensile strength varies with tempering temperature.
What is the melting temperature of pure nickel (Ni)?
The melting temperature of pure Ni is 1455°C.
In the isothermal transformation diagram for alloy steel 4340, what does 'P' stand for?
Pearlite.
What is the melting temperature of pure copper (Cu)?
The melting temperature of pure Cu is 1085°C.
What does Wβ represent in phase diagram calculations?
The weight fraction of phase β.
What is Proeutectoid ferrite?
Ferrite that is formed above the eutectoid temperature.
What is the significance of the continuous-cooling transformation diagram for alloy steel?
It helps in understanding the microstructure development during cooling.
What is the equation for the force of phase γ in Lever's rule?
F γ = S * F total / (R + S).
What is the significance of cooling in the context of lead-tin alloys?
Cooling affects the microstructure and properties of the alloy.
What is the solid solubility limit for Cu in Ag at 779 °C?
CβE = 8.8 % wt Cu (or 91.2 % wt Ag).
What is the type of steel discussed in the continuous-cooling transformation diagram?
Alloy steel type 4340.
What does an isothermal transformation phase diagram of Fe-C alloy represent?
It shows the phases present in the alloy at a constant temperature.
What does the Cu-Ni phase diagram represent?
The phase relationships between copper (Cu) and nickel (Ni) at various temperatures and compositions.
How does the temperature of deformation affect Bainite formation?
Bainite can form as needles or plates, depending on the temperature of deformation.
What is the significance of the cooling rate in the continuous cooling transformation diagram?
The cooling rate affects the microstructure and phase transformations of the alloy.
What type of alloy is represented in the continuous cooling transformation diagram?
Eutectoid iron-carbon alloy.
What are the key phases identified in the Fe-C isothermal transformation diagram?
Austenite, Ferrite, Cementite, and Pearlite.
What is the composition of the α phase in the Cu-Ni alloy?
37% Ni and 63% Cu.
What is the significance of uniform composition in a solid solution?
It indicates that the elements combine to give a consistent structure and properties.
What is the composition of the first solid phase formed in a 50% wt Ni – 50% wt Cu alloy?
The composition can be determined from the phase diagram at the temperature of the first solid phase.
What is the significance of the continuous cooling transformation diagram for a eutectoid Fe-C alloy?
It depicts how the phases change as the temperature decreases continuously.
What is the role of carbon content in the isothermal transformation of Fe-C alloys?
Carbon content influences the stability and transformation of phases.
What is the eutectoid composition in the Fe-C alloy system?
Approximately 0.76% carbon.
What type of solid solutions are present in the Copper-Zinc phase diagram?
Terminal solid solutions and Intermediate solid solutions.
What does R and S represent in the context of Lever's rule?
R and S represent the amounts of two different phases in a mixture.
What are the characteristics of cementite?
Hard and brittle.
What are the primary phases present in the lead-tin phase diagram?
Liquid, solid lead (α-phase), and solid tin (β-phase).
What is tempered martensite?
Martensite formed by heating to a temperature below eutectoid for a long period.
How long is spheroidite typically formed?
Approximately 18 to 24 hours.
What does the Magnesium-Lead phase diagram represent?
The relationship between temperature and composition for magnesium and lead alloys.
What phase is represented by the letter 'B' in the isothermal transformation diagram?
Bainite.
What is the microstructure of tempered martensite?
Very small and uniformly dispersed cementite particles in a ferrite matrix.
Why is isothermal transformation important in Fe-C alloys?
It helps in understanding the microstructural changes during cooling.
What is the significance of heating martensite during tempering?
It allows for the formation of a more stable microstructure.
What does the number 90 represent in the context of the Magnesium-Lead phase diagram?
It likely refers to a specific composition percentage of magnesium or lead in the alloy.
What type of alloy is spheroidite associated with?
Fe-C alloy (Iron-Carbon alloy).
What are the key microstructures found in iron-carbon alloys?
The key microstructures include pearlite, ferrite, cementite, and martensite.
In what matrix is martensite found?
In an austenite matrix.
What is microstructure in the context of metals?
The arrangement of phases and grains in a metal, which influences its properties.
What is the significance of the Cu-Ni phase diagram in this problem?
It helps determine the temperature (T) at which the specified compositions coexist at equilibrium.
What does W γ represent in Lever's rule?
Weight fraction of phase γ.
How can the temperature (T) of the Cu-Ni alloy be found?
By referring to the Cu-Ni phase diagram for the given compositions.
What is Proeutectoid α?
Ferrite that forms before the eutectoid transformation in hypoeutectoid compositions.
What phases does steel usually consist of?
α + Fe₃C.
What does the β phase represent in the Copper-Zinc phase diagram?
Another terminal solid solution.
What is the composition of the liquid phase in a 40 wt % Sn - 60 wt % Pb alloy at 150 °C?
The composition of the liquid phase is approximately 45 wt % Sn.
What is the stable form of pure iron at room temperature?
Ferrite (α-iron) with a BCC structure.
What are the two primary components of the Copper-Silver phase diagram?
Copper and silver.
How does the presence of cementite affect the properties of iron-carbon alloys?
Cementite increases hardness and strength but decreases ductility.
What is the carbon content range for steel?
0.008 - 2.14 wt%C.
What does 'W α' denote in the Cu-Ni phase diagram?
It refers to a specific solid solution phase in the diagram.
What is the typical carbon content in steel?
Usually less than 1 wt%C.
What is a component in the context of a system?
A chemically independent constituent of a system.
What is the composition of the solid phase (α phase) in a 40 wt % Sn - 60 wt % Pb alloy at 150 °C?
The composition of the solid phase is approximately 38 wt % Sn.
What happens to the lead-tin alloy as it cools past the eutectic temperature?
It solidifies into a mixture of solid lead and solid tin.
What defines a system at equilibrium?
A system is at equilibrium if its free energy is minimum under some specified combination of temperature, pressure, and concentration.
What is the significance of %RA in evaluating alloy steel?
%RA (percent reduction in area) indicates ductility.
Why is the continuous cooling transformation diagram important for Fe-C alloys?
It helps predict the microstructural changes during cooling processes.
What concept is used for Wα (or Wβ) + WL above T_E?
General Lever’s rule concept.
What type of iron-carbon alloy is being discussed?
An iron-carbon alloy of eutectoid composition.
How is the total force in a mixture expressed in Lever's rule?
F total = F γ + F β.
What is the significance of the eutectoid transformation in Fe-C alloys?
It leads to the formation of pearlite, which enhances strength and hardness.
What is formed at 6.7 wt % C in the Iron-Carbon system?
Cementite (Fe3C), an intermediate compound iron carbide.
What is the mass fraction of the liquid phase in the alloy?
The mass fraction of the liquid phase is calculated using the lever rule.
How does temperature affect the phases in an Fe-C alloy?
Different temperatures lead to different phase compositions and microstructures.
What is the significance of the equation 'S R + W L = W α'?
It indicates the equilibrium between solid and liquid phases in the Cu-Ni system.
How does the cooling rate affect isothermal transformation in Fe-C alloys?
It influences the final microstructure and mechanical properties.
What microstructure is formed during the slow cooling of iron-carbon alloys?
Pearlite is formed during slow cooling.
What role does composition play in metal alloys?
Composition determines the phases present and their proportions, affecting the alloy's properties.
What does the term 'Lever's rule' refer to in phase diagrams?
A method to calculate the proportions of different phases in a mixture.
What is the eutectic point in the Copper-Silver phase diagram?
The composition and temperature at which the liquid phase transforms into two solid phases simultaneously.
What does the γ phase indicate in the Copper-Zinc phase diagram?
It is also an intermediate solid solution.
What does 'F' represent in the isothermal transformation diagram for alloy steel 4340?
Proeutectoid ferrite.
What are the two properties analyzed in the copper-nickel system at room temperature?
Tensile strength and ductility (%EL).
What is the significance of the liquidus line in the Copper-Silver phase diagram?
It indicates the temperatures above which the alloy is completely liquid.
How does composition affect tensile strength in the copper-nickel system?
Tensile strength varies with composition.
At what temperature are the mechanical properties of Fe-C alloys measured?
At room temperature.
What are the time intervals mentioned in the data?
0.2s, 0.3s, and (0.5 + 10^4)s.
What is the role of the η phase in the Copper-Zinc phase diagram?
It represents a terminal solid solution.
What occurs under the upper liquidus line in a binary isomorphous system?
The system consists of only one phase: the liquid phase.
What does solubility refer to?
The ability of a substance to dissolve in a solvent.
What are the phases represented in the Copper-Zinc phase diagram?
α, β, ε, γ, η, and Liquid.
What is meant by metastable?
A state that is stable under certain conditions but can transition to a more stable state.
What happens to iron at 1538 °C?
It melts to liquid.
What is the total time for the last hold in the temperature profile?
10,000 seconds.
What phases are present in a 40 wt % Sn - 60 wt % Pb alloy cooled from 300 °C to 150 °C?
The phases present are the liquid phase and the solid phase (α phase).
At what composition does the eutectic point occur in the lead-tin phase diagram?
At approximately 61.9% tin and 38.1% lead.
What is a phase?
A material having the same composition, structure, and properties everywhere under equilibrium conditions.
What is the significance of ductility (%RA) in the context of Fe-C alloys?
Ductility indicates the ability of the alloy to deform plastically at room temperature.
What factors influence the mechanical properties of Fe-C alloys?
Composition, microstructure, and heat treatment.
What is the significance of α in the Fe-C system?
It represents the ferrite phase, which is a solid solution of carbon in iron.
What is the composition of the last remaining liquid phase in a 50% wt Ni – 50% wt Cu alloy?
The composition can be determined from the phase diagram at the temperature of the last liquid phase.
How does composition affect ductility in the copper-nickel system?
Ductility (%EL) varies with composition.
What is the typical carbon content range for steel in Fe-C alloys?
0.02% to 2.1% carbon.
What is a ferrous alloy?
An alloy containing Fe as a major component and some carbon or other components.
What is the significance of the eutectic point in the lead-tin phase diagram?
It represents the lowest melting point for the alloy and the composition at which the liquid phase transforms into two solid phases.
What is the temperature after holding for 20 seconds?
~20.6 degrees.
What is the role of carbon content in the Fe-C phase diagram?
It determines the stability and type of phases present at various temperatures.
How long is the second hold in the temperature profile?
1,000 seconds.
What does the solidus line represent in the Copper-Silver phase diagram?
The temperatures below which the alloy is completely solid.
What phase occurs between the liquidus and solidus lines in the Copper-Silver phase diagram?
A mixture of solid and liquid phases.
What is the carbon content range for cast iron?
2.14 - 6.7 wt%C.
What does the lead-tin phase diagram illustrate?
The phases and phase relationships of lead and tin alloys at various temperatures and compositions.
What is the structure of Austenite (γ-iron) at 912 °C?
FCC structure.
At what temperature does the last liquid solidify in a 50% wt Ni – 50% wt Cu alloy?
The last liquid solidifies at the temperature indicated by the phase diagram for the alloy.
At what temperature does Ferrite (δ-ferrite) exist?
At 1394 °C.
What is the temperature after holding for 1,000 seconds?
1020.6 degrees.
What does the α phase represent in the Copper-Zinc phase diagram?
A terminal solid solution.
What is the effect of heat treatment on the mechanical properties of Fe-C alloys?
Heat treatment can alter hardness, strength, and ductility.
How do you calculate the mass fraction of each microconstituent in the alloy?
Use the lever rule based on the compositions and total mass of the phases.
What are the key components of a phase diagram?
Phases, boundaries, temperature, and overall composition.
What are mechanical properties in metals?
Characteristics such as strength, ductility, and hardness that determine how a metal behaves under stress.
How does carbon content affect the hardness of Fe-C alloys?
Increased carbon content generally increases hardness.
What phases are typically present in a eutectoid Fe-C alloy at equilibrium?
Austenite, ferrite, and cementite.
What characterizes a Hypoeutectoid composition?
It contains less than 0.76% wt C.
What is the typical carbon content in cast iron?
Usually less than 4.5 wt%C.
What phase is represented by the liquid state in the Copper-Zinc phase diagram?
The liquid phase before solidification occurs.
What is developed during the equilibrium solidification?
Microstructure.
What type of alloy is referenced in the phase diagram?
Lead-Tin alloy.
What is martensite and how is it formed?
Martensite is a hard microstructure formed by rapid cooling (quenching) of austenite.
What transformation occurs in a eutectoid Fe-C alloy upon cooling?
Austenite transforms into pearlite.
What is the significance of the ε phase in the Copper-Zinc phase diagram?
It represents an intermediate solid solution.
What is the mass fraction of the solid phase (α phase) in the alloy?
The mass fraction of the solid phase is calculated using the lever rule.
