1. Crystals. The atoms are periodically and regularly arranged in three-dimensional space in a certain way, with a fixed melting point and anisotropy.
2. Intermediate phase.
When two components A and B form an alloy, in addition to forming a or B-based solid solution, a new phase may also be formed with a crystal structure that is different from that of both A and B. Since their position on the binary phase diagram is always in the middle, these phases are often referred to as mesophases.
3. Metastable phase.
The metastable phase refers to a phase that cannot be thermodynamically stable, but temporarily stabilizes due to thermodynamic energy barriers or kinetic factors that fail to transform into a stable phase during the rapid cooling into heating.
4. Coordination number.
The number of nearest neighbors and equidistant atoms around any atom in a crystal structure.
5. Recrystallization.
After the cold-deformed metal is heated to a certain temperature, new grains without distortion are regenerated in the original deformed structure, and the properties also change significantly and return to the state before deformation, a process called recrystallization. (refers to the process of the gradual replacement of deformed grains by new equiaxed grains without distortion).
6. Pseudo-eutectic.
Under the condition of non-equilibrium solidification, some alloys with subeutectic or supereutectic composition can also obtain all eutectic microstructures, and the eutectic microstructures obtained from alloys with non-eutectic compositions are called pseudoeutectics.
7. Cross-slipping.
When the movement of a spiral dislocation is blocked on the original slip surface, it is possible to transfer from the original slip surface to another slip surface that intersects it to continue sliding, which is called cross-slip.
8. Expiration time.
After the aluminum alloy is treated by solid solution, it will be precipitated out of the GP zone in the process of heating and insulation. At the beginning of the insulation stage, with the extension of the holding time, the hardness strength increases, when the holding time is too long, it will be precipitated, and the hardness strength of the material will decrease, this phenomenon is called obsolescence.
9. Deformation strengthening.
After the metal is deformed by cold plasticity, its strength and hardness increase, and the plasticity and toughness decrease, this phenomenon is called deformation strengthening.
10. Solution strengthening.
The phenomenon that the strength of an alloy based on metal is strengthened due to the addition of alloying elements (impurities).
11. Diffusion strengthening.
Many materials are composed of two or more phases, and if one of the phases is fine particles and distributed difusely within the material, the strength of this material tends to increase, known as dispersion strengthening.
12. Incomplete dislocation.
A dislocation in which the Burger vector is not equal to an integer multiple of the lattice vector is called an incomplete dislocation.
13. Extended dislocations.
It usually refers to the decomposition of a total dislocation into two incomplete dislocations, with a stacked dislocation in between.
14. Screw dislocation.
A dislocation in which the atoms in the vicinity of the dislocation line are arranged in a spiral shape is called a spiral dislocation.
15. Cladding transformation.
In the binary phase diagram, the cladding transition is the constant temperature transition in which the crystallized solid phase reacts with the remaining liquid phase to form another solid phase.
16. Eutectic transformation.
A transition from one liquid phase to two different solid phases.
17. Eutectic transformation.
The decomposition of one solid phase results in the transformation of two other different solid phases.
18. Uphill diffusion.
The process of diffusion of solute atoms from low to high concentrations is known as uphill diffusion. Indicates that the driving force of diffusion is the niche gradient rather than the concentration gradient.
19. Interstitial diffusion.
This is a mechanism of atomic diffusion, for interstitial atoms, due to their small size, in the lattice gap, when diffusion, click on the **eighteen essential software. The interstitial atoms jump from one interstitial position to another adjacent interstitial position, forming the movement of the atoms.
20. The ingredients are supercooled.
Supercooling occurs when the actual temperature in the liquid at the interface front is lower than the solidification temperature, which is determined by the solute distribution.
21. First-order phase transition.
Where the chemical potential of the old and new phases is equal, the phase transition of the chemical potential is not equal at the first partial conduction.
22. Second-order phase transition:
In terms of phase transition thermodynamics, the free energy (enthalpy) of the two phases before and after the phase transition is equal, and the first-order partial derivative of the free energy (enthalpy) is equal, but the phase transition with unequal second-order partial derivatives is called the second-order phase transition, such as magnetic transition, order-disorder transition, constant-superconducting transition, etc.
23. Co-lattice boundary.
If all the atoms at the interface of the two phases are in a one-to-one exact match, that is, the atoms on the interface are at the junction of the two-phase lattice at the same time, which is common to the two adjacent crystals, this phase boundary is called the co-lattice phase boundary.
24. Amplitude modulation decomposition.
The process by which a supersaturated solid solution is decomposed into two phases with the same structure and different compositions at a certain temperature.
25. Tempering brittleness.
In the tempering process, the plasticity and toughness of quenched steel generally increase with the increase of tempering temperature, but in a specific tempering temperature range, the phenomenon of decreasing toughness is called tempering brittleness. For steel materials, there are types 1 and 2 tempered brittleness. They differ in temperature ranges, influencing factors, and characteristics.
26. Recrystallization annealing.
The so-called recrystallization annealing process generally refers to the process of heating the cold-deformed metal above the recrystallization temperature, holding it for a period of time, and then slowly cooling it to room temperature.
27. Tempered sostenite.
The tempered structure formed by tempering of quenched steel after tempering at a temperature of 400-600 °C is composed of equiaxed ferrite and fine granular (worm-like) cementite.
28. Ordered solid solution.
When one component is dissolved in another, the atoms of each component occupy a solid solution of their respective Bravi lattice, forming a solid solution in which the atoms of each component are arranged in an orderly manner, and the solutes are completely arranged in the crystal lattice.
29. Non-uniform nucleation.
The new phase preferentially nucleates at heterogeneous parts present in the parent phase, i.e., impurities or foreign surface nucleations attached to the liquid phase.
30. Martensite phase transition.
The phase transformation process of a high-hardness needle-like structure formed by rapid quenching after heating to austenite in steel.
31. Bainite phase transition.
The transition of steel in the range (550 -230) below the pearlite transition temperature and above the martensitic transition temperature is called bainite transition.
32. The aging of aluminum alloy.
The phenomenon that the strength and hardness of the quenched aluminum alloy increase significantly with the extension of time is called aging, also known as the aging of aluminum alloy.
33. Thermoelastic martensite.
The martensite phase transition causes elastic strain, and when elastic denaturation is applied, the martensite phase transition can be reversed, and this martensite is called thermoelastic martensite. Click on the eighteen must-have software. or martensite phase transitions are coordinated by elastic denaturation. This martensite is called thermoelastic martensite.
34. The Kirkendal effect.
Reflecting the diffusion mechanism of the displaced atoms, the two pure components form a diffusion couple, and in the process of diffusion, the interface will move to the side of the component with the fast diffusion rate.
35. Thermoelastic martensitic phase transformation.
When the shape change of the martensitic phase transition is coordinated by elastic deformation, it is called thermoelastic martensite phase transition.
36. Amorphous.
Atoms do not have a long-range periodic arrangement, no fixed melting point, isotropic, etc.
37. Density.
The percentage of the atomic volume in the crystal structure as a percentage of the total volume.
38. Multi-slip.
When the slitting stress of the external force on several slip systems is equal and reaches the critical slitting stress at the same time, the phenomenon of simultaneous slip occurs.
39. Supercooling.
In the process of phase change, the transition occurs after cooling to a certain temperature below the phase transition point, and the difference between the equilibrium phase transition temperature and the actual transition temperature is called the supercooling.
40. an interstitial phase.
When the ratio of the atomic radius of the non-metal (x) and the metal (m) rx rm<059, a phase with a simple crystalline structure is formed, which is called an interstitial phase.
41. Total dislocation.
Dislocations where the Burger vector is equal to the lattice vector or its integer multiples are called total dislocations.
42. a slip system.
The combination of a slip surface and a slip direction on that surface in a crystal is called a slip system.
43. Divorced eutectic.
The phase in the eutectic is attached to the primary phase to grow, and the other phase in the co-crystal is pushed to the final solidified grain boundary, so that the microstructure characteristics of the two constituent phases of the co-crystal disappear, and the co-crystal separated from the two phases is called dissimilar eutectic.
44. Uniform nucleation.
The new phase nucleus is uniformly grown in the presence of the parent phase, that is, the crystal nucleus is directly formed by some atomic clusters in the liquid phase, and is not affected by impurity particles or the outer surface.
45. Blade dislocation.
A certain crystal plane in the crystal has an extra half row of atomic planes in its upper half, like a knife blade inserted into the crystal, so that the atomic misalignment between the upper and lower parts of the crystal on this crystal plane is generated, which is called blade-shaped dislocation.
46. Fine-grained strengthening.
The finer the grains, the longer the total length of the grain boundaries, the greater the resistance to dislocation slip, and the higher the yield strength of the material. Grain refinement leads to an increase in grain boundaries and hindered slip of dislocations, thus increasing the strength of the material.
47. Double-cross slip.
If the dislocation after cross-slip is turned back to the slip plane parallel to the original slip surface and continues to move, it is called cross-slip.
48. Unit dislocation.
The dislocation of the Burger vector equal to the unit lattice vector is called the unit dislocation.
49. Reaction diffusion.
Diffusion that is accompanied by a chemical reaction to form a new phase is called reactive diffusion.
50. Grain boundary segregation.
Enrichment of solute atoms or impurity atoms at grain boundaries due to the difference in distortion energy within the grain or due to the presence of vacancies.
51. Kokoff air mass.
The phenomenon of segregation around the dislocation after the interaction between solute atoms and dislocations is usually called an air mass, which was first proposed by Curiel, also known as a Corotkoff gas mass.
52. Deformation and texture.
The phenomenon of the best crystallographic orientation in the polycrystalline deformation process is called deformation texture.
53. Lattice distortion.
On a local scale, atoms deviate from their normal lattice equilibrium position, causing lattice distortion.
54. Steady-state diffusion.
In the steady-state diffusion process, the concentration of the diffusion component varies only with distance and not with time.
55. Encapsulation reaction.
The process of obtaining a solid phase from the reaction of two solid phases is called the encapsulation reaction.
56. Non-concomitant grain boundaries.
When the atomic arrangement of the two phases at the phase boundary is very different, that is, the mismatch degree δ is very large, a non-coherent grain boundary is formed. Similar to large-angle grain boundaries, it can be seen as a thin transition layer composed of atoms arranged irregularly.
57. Replacing the solid solution.
When the solute atoms dissolve into the solvent to form a solid solution, the solute atoms occupy the lattice of the solvent, or the solute atoms replace part of the solvent atoms in the solvent lattice. This solid solution is called a displacement solid solution.
58. a solid solution in the interstitial space.
The solid solution formed by the distribution of solute atoms in the interstitial space of the solvent lattice is called the interstitial solid solution.
59. Secondary recrystallization.
After the end of recrystallization, the normal growth of a small number of grains is inhibited, and the abnormal growth of a small number of grains occurs.
60. Pseudo-euanalytic transformation.
In the process of non-equilibrium transformation, the sub-eutectic and super-eutectic alloys near the eutectic component point are all eutectic structures at the end of the transformation.
61, Xiao Deji vacancy.
In the crystal in an individual, when an atom has a large enough vibrational energy to increase the amplitude to a certain extent, it may overcome the restriction of the surrounding atoms, jump away from its original position, and migrate to the normal node position on the surface or inner surface of the crystal, leaving a vacancy inside the crystal, which is called a vacancy in the crystal.
62. Frankl vacant.
Atoms leaving the equilibrium position squeeze into the gap position in the lattice, while an equal number of vacant and gap atoms are formed simultaneously in the crystal.
63. Unsteady diffusion.
The diffusion in which the concentration of the diffusion component varies not only with distance x but also with time is called unsteady diffusion.
64. Statute of limitations.
The supersaturated solid solution is followed by the desolubilization of solute atoms at or above room temperature.
65. Reply.
Refers to the stage of substructural and property changes that occur before the emergence of new distortion-free grains.
66. Phase.
The phase law gives the relationship between the number of phases and the number of components, temperature and pressure in the equilibrium state ** system, which can be expressed as: f=c+p-2, f is the number of degrees of freedom of the system, c is the number of components of the system, and p is the number of phases.
67. an alloy.
A substance consisting of two or more metals or a combination of metals and non-metals by smelting, sintering or other methods and having metallic properties.
68. a twin.
Twinning refers to the symmetrical orientation relationship between two crystals (or two parts of a crystal) along a common crystal plane, which is called a twin, and this common crystal plane is called a twin plane.
69. a phase diagram.
** that describes the existence of conditions or coexistence relations in the equilibrium of each phase can also be referred to as the geometric trajectory of the thermodynamic parameters at equilibrium.
70. Twins.
After the crystal is stressed, the shear process that occurs in the form of twins is called twinning.
71. Grain boundaries.
Grain boundaries are interfaces between grains of the same kind with the same composition and structure.
72. a unit cell.
A representative basic unit (the smallest parallelepiped) is taken out of the lattice as the constituent unit of the lattice, which is called the unit cell.
73. Dislocation.
It is a kind of line defect in the crystal, which is characterized by the regular misalignment of atoms along a line direction; This defect is described by a line direction and a Burgers vector.
74. Segregation.
Inhomogeneity of chemical composition in alloys.
75. a metal key.
The bonding force produced by the electrostatic interaction between the free electron and the nucleus.
76. a solid solution.
It is a homogeneously mixed solid solution formed by dissolving other component atoms (solvent atoms) into its crystal lattice with a certain component as a solvent, which maintains the crystal structure type of the solvent.
77. a subcrystalline.
Grains with slightly different phases in a grain are called subcrystals.
78. Subgrain boundaries.
The interface between adjacent subgrains is called a subgrain boundary.
79. Grain boundary energy.
Whether it is a small-angle grain boundary or a large-angle grain boundary, the atoms here are more or less off the equilibrium position, so the grain boundary is in a higher energy state relative to the inside of the crystal, and the higher part of the energy is called the grain boundary energy, or grain boundary free energy.
80. Surface energy.
The surface atoms are in an inhomogeneous force field, so their energy is greatly increased, and the energy that rises is called the surface free energy (or surface energy).
81. The interface can.
The atoms at the interface are in a broken bond state and have excess energy. The average excess energy per unit area of the interface is called the interface energy.
82. Hardenability.
Hardenability refers to the ability of an alloy to quench into martensitic, which is mainly related to the critical cooling rate, and the magnitude is expressed by the depth of the hardened layer.
83. Hardenability.
Hardenability refers to the highest hardness that can be achieved after quenching, which is mainly related to the carbon content of the steel.
84. Habitual surface.
During the solid-state phase transition, the new phase often begins to form in a certain crystal plane of the parent phase, which is called the habitual plane.
85. Soxenite.
The pearlite transition product in the middle temperature section is composed of flake ferrite cementite, with small spacing between layers and thin sheets.
86. Pearlite.
The product of the eutectic transformation of iron-carbon alloys is a laminar mixture of eutectic ferrite and eutectic cementite.
87. Lederaceta.
The product of the eutectic transition of the iron-carbon phase diagram is a mechanical mixture of eutectic austenite and eutectic cementite.
88, Burg vector.
It is an important vector to describe the dislocation features, which concentrates on the magnitude and direction of the total amount of distortion in the dislocation region, and also makes the crystal slide relative to each other after the dislocation is swept.
89. a spatial lattice.
It refers to the three-dimensional array formed by the periodic regular arrangement of geometric points in three-dimensional space, which is an artificial abstraction of crystal structure.
90, Van der Waals key.
A physical bond consisting of an instantaneous dipole moment and an intermolecular gravitational force resulting from an induced dipole moment.
91. Dislocation slippage.
A dislocation motion in which the dislocation line moves along the slip surface under a certain stress.
92. Heterogeneous nucleation.
Crystal nuclei are formed in liquid metals on the surface of foreign substances or at uneven temperatures.
93. The structure fluctuates.
The atoms of the liquid structure are arranged in a long-range disordered and short-range ordered, and the short-range ordered atomic cluster is not fixed. Structures that are dimensionally unstable, a phenomenon known as structural undulations.
94. The law of the center of gravity.
In a three-phase equilibrium alloy, the composition point must be located at the center of gravity of the conjugate triangle.
95. Strain aging.
Immediately after the first stretch, the second stretch is carried out without a yield phase on the stretch curve. However, after the first stretch, the mild steel specimen is left at room temperature for a period of time, and then the second stretch is performed, and the yield phase will appear on the tensile curve. However, the strength of the second yield is higher than the strength of the initial yield. This test phenomenon is called strain aging.
96. Dendrite segregation.
Under the condition of non-equilibrium cooling, the internal composition of the newly obtained solid solution grains after homogeneous transformation is uneven, the inner core of the first crystallization contains more components with high melting point, and the outer edge of the later crystallization contains more component atoms with low melting point, and usually the solid solution crystals grow in the form of dendrites, so that the branches contain more components with high melting points, and the branches contain more atoms with low melting points, resulting in the unevenness of the internal composition of the same grain.
97. Critical deformation.
The minimum amount of pre-cold deformation required for recrystallization of the metal at a given temperature.
98. Electronic compounds.
Electronic compounds refer to a class of compounds whose crystal structure is determined by the concentration of major electrons, also known as the Hume-Rosselli phase. Wherever there is the same electron concentration, the crystal structure type of the phase is the same.
99. Homogeneous isomers.
Different crystal structures formed due to different thermodynamic conditions due to the same chemical composition.
100. Recrystallization temperature.
The minimum temperature at which the deformed metal can be recrystallized within a certain period of time (generally 1h).
101. Brafi dot matrix.
In addition to the unit cell shape, the lattice formed by the position of the lattice is also considered.
102. a coordination polyhedron.
A polyhedron formed by the central line of atoms or ions that surround an atom or ion that binds directly adjacent to it is called a coordination polyhedron of an atom or ion.
103. Schmidt factor.
Also known as the orientation factor, it is cos cos, which is the angle between the slip surface and the central axis of the external force f, and the angle between the slip direction and the external force f.
104. Topological dense heap phase.
A type of intermediate phase composed of two metal atoms of different sizes, in which the large and small atoms form a complex structure with high space efficiency and coordination number through appropriate coordination. Because of the topological characteristics of this type of structure, these phases are called topological dense pile phases.
105. Interstitial compounds.
When the ratio of the atomic radius of the non-metal (x) and the metal (m) rx rm<0At 59, a phase with a complex crystal structure is formed, often referred to as an interstitial compound.
106. Large-angle grain boundaries.
The grain boundaries between the grains in polycrystalline materials are called large-angle grain boundaries, that is, the grain boundaries where the position difference of adjacent grains is greater than 10.
107. Small-angle grain boundaries.
The difference between adjacent subgrains is less than 10, and the grain boundaries between the subgrains are called small-angle grain boundaries, which are generally less than 2, and can be divided into inclined grain boundaries, torsional grain boundaries, coincident grain boundaries, etc.
108. Critical slitting stress.
the minimum slitting stress required for the sliding system to start; It is a fixed value, which is related to the properties of the material itself, and has nothing to do with the orientation of external forces.