China factory manufacture precision dental equipment parts
- Crystal
Atoms are regularly and regularly arranged in a certain manner in three-dimensional space, with fixed melting points and anisotropy. China factory manufacture precision dental equipment parts - Mesophase
When the two components A and B form an alloy, in addition to forming a solid solution based on A or B, crystals may also be formed.
A new phase whose structure is different from the two components A and B. Since their position on the binary phase diagram is always in the middle, usually
These phases are called mesophases. - Metastable phase
The metastable phase refers to a phase that cannot exist thermodynamically stably, but during the rapid cooling to heating process, due to the thermodynamic energy barrier or
A phase that is temporarily stable due to kinetic factors causing it to fail to transform into a stable phase. - Coordination number
The number of nearest equidistant atoms surrounding any atom in a crystal structure. - 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 undergo significant changes and return to the state before deformation. This process is called recrystallization. (Indicates the presence or absence of distortion
The process in which equiaxed new grains gradually replace deformed grains) China factory manufacture precision dental equipment parts - Pseudoeutectic
Under non-equilibrium solidification conditions, some alloys with hypoeutectic or hypereutectic compositions can also obtain full eutectic structures. This is due to
The eutectic structure obtained from alloys with non-eutectic components is called pseudoeutectic. - Cross slip
When a screw dislocation is blocked from moving on the original slip plane, it may transfer from the original slip plane to another slip plane that intersects with it.
The sliding continues on the transferred surface. This process is called cross-slip. - Time expired
After solid solution treatment, the aluminum alloy will successively precipitate the GP zone, θ ”, θ ’, and θ during the heating and heat preservation process. At the beginning
During the heat preservation stage, as the heat preservation time increases, the hardness and strength increase. When the heat preservation time is too long, θ ’ will precipitate. At this time, the hardness of the material
The strength will decrease, a phenomenon called overaging. - Deformation strengthening
After metal undergoes cold plastic deformation, its strength and hardness increase, and its plasticity and toughness decrease. This phenomenon is called deformation
strengthen. - Solid solution strengthening
The phenomenon that the strength of an alloy based on metal is enhanced due to the addition of alloying elements (impurities). China factory manufacture precision dental equipment parts - Diffusion enhancement
Many materials are composed of two or more phases. If one of the phases is fine particles and dispersed in the material,
The strength of the material tends to increase, which is called dispersion strengthening. - Incomplete dislocation
Dislocations whose Burgers vector is not equal to an integer multiple of the lattice vector are called incomplete dislocations. - Extended dislocation
Usually refers to the entire dislocation morphology in which a total dislocation is decomposed into two incomplete dislocations with a stacking fault sandwiched between them. - Screw dislocation
A dislocation in which the atoms near the dislocation line are arranged in a spiral shape is called a screw dislocation. - Peritectic transformation
In the binary phase diagram, the peritectic transition is a isothermal transition in which a crystallized solid phase reacts with the remaining liquid phase to form another solid phase. - Eutectic transformation
Transition from one liquid phase to two different solid phases. - Eutectoid transformation
The transformation from the decomposition of one solid phase to two other different solid phases. - Uphill diffusion
The process of diffusion of solute atoms from low concentration to high concentration is called uphill diffusion. Shows that the driving force for diffusion is the chemical potential ladder
degree rather than concentration gradient. China factory manufacture precision dental equipment parts - Gap diffusion
This is a mechanism of atomic diffusion. For interstitial atoms, due to their small size, they are in the lattice gap.
When spreading, click to download eighteen essential software. Interstitial atoms jump from one interstitial position to another adjacent interstitial position, forming a movement of atoms. - Ingredients are too cold
Supercooling occurs when the actual temperature in the liquid at the interface front is lower than the solidification temperature determined by the solute distribution. - First-order phase change
If the chemical potentials of the old and new phases are equal, the primary partial derivatives of the chemical potentials are not equal. - Secondary phase change:
From the perspective of phase change thermodynamics, the free energy (enthalpy) of the two phases before and after the phase change is equal, and the first-order partial derivative of the free energy (enthalpy) of the phase
etc., but phase transitions with unequal second-order partial derivatives are called second-order phase transitions, such as magnetic transitions, order-disorder transitions, and normal-conducting-superconducting transitions. China factory manufacture precision dental equipment parts
wait. - Consistent phase boundary
If all the atoms on the two-phase interface have a perfect one-to-one matching relationship, that is, the atoms on the interface are in both phases at the same time.
The nodes of the phase lattice are shared by two adjacent crystals, and this phase boundary is called a coherent phase boundary. - AM decomposition
The process in which a supersaturated solid solution decomposes into two phases with the same structure and different compositions at a certain temperature. - Tempering brittleness
During the tempering process of quenched steel, generally as the tempering temperature increases, its plasticity and toughness increase, but under certain conditions
Within the tempering temperature range, the phenomenon of reduced toughness is called temper brittleness. For steel materials there are first and second categories
Temper-like brittleness. Their temperature ranges, influencing factors and characteristics differ. - Recrystallization annealing
The so-called recrystallization annealing process generally refers to heating the cold-deformed metal to above the recrystallization temperature and keeping it warm for a period of time.
Then slowly cool to room temperature. - Tempered sorbite
The tempered structure formed after quenching steel is heated to 400-600°C and tempered. It is composed of equiaxed ferrite and fine
Composed of granular (worm-like) cementite. - Ordered solid solution
When one component is dissolved in another component, the atoms of each component occupy their own Bravais lattice.
The body forms a solid solution in which the atoms of each component are arranged in an orderly manner, and the solutes are completely arranged in an orderly manner in the crystal lattice. - Non-uniform nucleation
The new phase preferentially nucleates at heterogeneous locations present in the parent phase, i.e., nucleates on impurities or foreign surfaces attached to the liquid phase. - Martensite transformation
The phase transformation process of high-hardness needle-like structure formed in steel after being heated to austenite and then rapidly quenched. China factory manufacture precision dental equipment parts - Bainite transformation
The transformation of steel below the pearlite transformation temperature and above the martensite transformation temperature (550°C-230°C) is called pearlite transformation.
Shitenite transformation. - Aging of aluminum alloy
The phenomenon that the strength and hardness of quenched aluminum alloys significantly increase with time is called aging, also known as aluminum alloy.
Gold’s time limit. - Thermoelastic martensite
Martensitic transformation causes elastic strain, and when elastic deformation is applied, the martensite transformation can be reversed. This martensitic transformation
martensite is called thermoelastic martensite. Click to download eighteen essential software. Or martensite transformation is coordinated by elastic degeneration. This kind of martensite is called thermoelastic martensite. - Kirkendall Effect
Reflecting the diffusion mechanism of replacement atoms, two pure components form a diffusion couple. During the diffusion process, the interface will diffuse toward
The faster component moves on one side. - Thermoelastic martensite transformation
When the shape change of martensitic transformation is coordinated by elastic deformation, it is called thermoelastic martensitic transformation. - Amorphous
Atoms have no long-range periodic arrangement, no fixed melting point, isotropy, etc. China factory manufacture precision dental equipment parts - Density
The atomic volume as a percentage of the total volume in a crystal structure. - Multiple slippage
When the shearing stresses of the external force on several slip systems are equal and reach the critical shearing stress at the same time, simultaneous slip will occur.
Phenomenon. - Supercooling
During the phase change process, the phase transition occurs after cooling to a certain temperature below the phase transition point. The equilibrium phase transition temperature is between the equilibrium phase transition temperature and the actual transition temperature.
The difference is called subcooling. - Gap phase
When the ratio of non-metal (X) and metal (M) atomic radii rX/rM<0.59, a simple crystal structure is formed
The phase is called the gap phase. - Total dislocation
Dislocations in which the Burgers vector is equal to the lattice vector or an integer multiple thereof are called total dislocations. - Slip system
The combination of a slip surface in a crystal and a slip direction on that surface is called a slip system. - Divorced eutectic
The α phase in the eutectic grows attached to the primary α phase, pushing the other phase β in the eutectic to the final solidified grain boundary.
The structural characteristics of the two phases of the eutectic disappear, and this two-phase separated eutectic is called a divorced eutectic. China factory manufacture precision dental equipment parts - Uniform nucleation
The new phase crystal nuclei grow uniformly in the parent phase, that is, the crystal nuclei are directly formed by some atomic groups in the liquid phase and are not affected by
Influence of impurity particles or external surfaces. - Edge dislocation
A certain crystal face in the crystal has an extra half row of atomic faces in the upper part, like a knife blade inserted into the crystal, making this
A misalignment of atoms occurs between the upper and lower parts of a crystal plane, which is called an edge dislocation. - Fine grain strengthening
The finer the grains, the longer the total length of the grain boundaries, the greater the obstruction to dislocation slip, and the higher the yield strength of the material. fine grain
This leads to the increase of grain boundaries and hinders the slip of dislocations, thus increasing the strength of the material. - Double cross slip
If the dislocation after cross-slip then turns back to the slip plane parallel to the original slip plane and continues to move, it is called double cross-slip. - Unit dislocation
The dislocation whose Burger’s vector is equal to the unit lattice vector is called a unit dislocation. - Reaction diffusion
Diffusion accompanied by chemical reactions to form new phases is called reactive diffusion. - Grain boundary segregation
Due to the difference in distortion energy between the grain and the grain boundary or the existence of vacancies, solute atoms or impurity atoms are placed on the grain boundary.
enrichment phenomenon. China factory manufacture precision dental equipment parts - Korotkoff air mass
Usually, the phenomenon of segregation of solute atoms around the dislocation after the interaction with the dislocation is called air mass. It was first proposed by Cotraill.
proposed, also known as Korotkoff air mass. - Deformation texture
The phenomenon of preferential crystallographic orientation that occurs during the deformation process of polycrystals is called deformation texture. - Lattice distortion
On a local scale, atoms deviate from their normal lattice equilibrium positions, causing lattice distortion. - Steady-state diffusion
In the steady-state diffusion process, the concentration of diffusion components only changes with distance and does not change with time. - Encapsulation reaction
The process of obtaining a solid phase from the reaction of two solid phases is called the perclusion reaction. - Incoherent grain boundaries
When the atomic arrangement of the two phases at the phase boundary is very different, that is, when the mismatch degree δ is very large, an incoherent grain boundary is formed. same angle
Grain boundaries are similar and can be seen as consisting of a very thin transition layer with atoms arranged irregularly. - Replacement solid solution
When solute atoms dissolve into a solvent to form a solid solution, the solute atoms occupy the lattice points of the solvent lattice, or solute atoms
Some solvent atoms in the solvent lattice have been replaced. Click to download eighteen essential software. This solid solution is called a substitutional solid solution. - Interstitial solid solution
The solid solution formed by the distribution of solute atoms in the gaps of the solvent crystal lattice is called interstitial solid solution. - Second recrystallization
A phenomenon in which a few grains grow abnormally when normal growth is suppressed after recrystallization is completed. - Pseudoeutectoid transformation
During the non-equilibrium transformation process, the structures of hypoeutectoid and hypereutectoid alloys near the eutectoid composition point will all appear at the end of the transformation.
Eutectoid tissue morphology. China factory manufacture precision dental equipment parts - Schottky vacancy
In individual crystals, when an atom has enough vibration energy to increase the amplitude to a certain extent, it is possible
Overcome the constraints of surrounding atoms, jump away from its original position, and migrate to the normal node position on the surface or inner surface of the crystal.
This leaves a vacancy inside the crystal, which is called a Schottyl vacancy. - Frankel vacant position
Atoms that leave the equilibrium position squeeze into the interstitial positions in the lattice, and an equal number of vacancies and gaps are simultaneously formed in the crystal.
gap atoms. - Unsteady diffusion
Diffusion in which the concentration of diffusion components not only changes with distance x but also changes with time is called unsteady diffusion. - Timeliness
The subsequent desolvation process of solute atoms at or above room temperature from a supersaturated solid solution. - Reply
Refers to the stage of substructural and performance changes that occur before new distortion-free grains appear. - Phase law
The phase law gives the relationship between the number of phases, the number of components, temperature and pressure existing in the system in the equilibrium state, 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 phase number. - Alloy
Two or more metals or metals and non-metals are combined by smelting, sintering or other methods and have metallic characteristics. China factory manufacture precision dental equipment parts
sexual material. - Twins
Twins refer to two crystals (or two parts of a crystal) forming a mirror-symmetrical orientation relationship along a common crystal plane.
These two crystals are called twins, and the common crystal plane is called the twin plane. - Phase diagram
A diagram describing the equilibrium conditions or coexistence relationships of each phase can also be called 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. - Grain boundary
Grain boundaries are the interfaces between the same type of grains with the same composition and structure. - Unit cell
Take out a representative basic unit (minimum parallelepiped) in the lattice as the component unit of the lattice, which is called
is the unit cell. - Dislocation
It is a line defect in the crystal, which is characterized by regular misalignment of atoms along a line direction; this defect is represented by a
The line direction is described together with a Burgers vector. - Segregation
Inhomogeneity of chemical composition in an alloy. - Metal key
The bonding force generated by the electrostatic interaction between free electrons and atomic nuclei. - Solid solution
It is a uniform mixture formed by using a certain component as a solvent and dissolving atoms of other components (solvent atoms) into its crystal lattice.
A solid solution that retains the crystal structure of the solvent. - Sub-grain
Several grains with slightly different phases in a grain are called sub-grains. - Sub-grain boundary
The interface between adjacent subgrains is called subgrain boundary. - Grain boundary energy
Whether it is a small-angle grain boundary or a high-angle grain boundary, the atoms here are more or less deviated from the equilibrium position, so relative to
Inside the crystal, the grain boundaries are in a higher energy state, and the higher energy is called grain boundary energy, or grain boundary free energy. China factory manufacture precision dental equipment parts - Surface energy
Surface atoms are in a non-uniform force field, so their energy is greatly increased. The higher energy is called surface free energy (or
surface energy). - Interface energy
The atoms on 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
able. - Hardenability
Hardenability refers to the ability of an alloy to be quenched into martensite, which is mainly related to the critical cooling rate. The size is expressed by the depth of the quenching layer. - Hardenability
Hardenability refers to the highest hardness that steel can achieve after quenching, which is mainly related to the carbon content of steel. - Habitual aspect
During a solid-state phase change, a new phase often begins to form on a certain crystal plane of the parent phase. This crystal plane is called the habit plane. - Sorbite
The pearlite transformation product in the middle temperature range is composed of lamellar ferrite cementite, with small spacing between lamellae and thin lamellae. - Pearlite
The product of the eutectoid transformation of iron-carbon alloys is a lamellar mixture of eutectoid ferrite and eutectoid cementite. - ledeburite
The product of the eutectic transformation of the iron-carbon phase diagram is a mechanical mixture of eutectic austenite and eutectic cementite. - Burger’s vector
An important vector describing the characteristics of dislocation, it reflects the total amount and direction of distortion in the dislocation region, and also makes
The amount of relative sliding of the crystal after a dislocation sweeps through it. - Space lattice
Refers to the three-dimensional array formed by the periodic and regular arrangement of geometric points in three-dimensional space. It is an artificial extraction of the crystal structure.
elephant. China factory manufacture precision dental equipment parts - Van der Waals bond
A physical bond formed by the intermolecular attraction generated by instantaneous dipole moments and induced dipole moments. - Dislocation slip
Under the action of a certain stress, the dislocation line moves along the slip plane. - Heterogeneous nucleation
Crystal nuclei are preferentially formed in liquid metals on the surface of foreign substances or at uneven temperatures. - Structural ups and downs
The atoms in the liquid structure are arranged into long-range disorder and short-range order, and the short-range ordered atomic groups are not fixed.
One thing changes and the other changes rapidly. Click to download 18 essential software. Dimensionally unstable structures, a phenomenon called structural heaving. - Law of center of gravity
The atoms in the liquid structure are arranged into long-range disorder and short-range order, and the short-range ordered atomic groups are not fixed.
One thing changes and the other changes rapidly. Click to download 18 essential software. Dimensionally unstable structures, a phenomenon called structural heaving.
94.Law of center of gravity
For an alloy in three-phase equilibrium, its composition point must be located at the center of gravity of the conjugate triangle.
- Response time
After the first stretching, the second stretching is performed immediately, and there is no yield stage on the stretching curve. But after the first stretch
After the low carbon steel sample is placed at room temperature for a period of time and then stretched for the second time, a yield stage will appear on the tensile curve.
part. However, the strength of yielding again is higher than the strength of initial yielding. This experimental phenomenon is called strain aging. China factory manufacture precision dental equipment parts - Dendrite segregation
Under non-equilibrium cooling conditions of a solid solution, the composition inside the new solid solution grains after the homogeneous transformation is uneven.
The inner core of the crystal contains more high-melting-point component atoms, and the outer edge of the later crystallization contains more low-melting-point component atoms. Usually,
The solid solution crystal grows in the form of dendrites. In this way, the branches contain more high-melting-point components, and the branches contain more atoms of low-melting-point components.
Causes uneven composition within the same grain. - Critical deformation degree
The minimum amount of prior cold deformation required for recrystallization of a metal at a given temperature. - Electronic compounds
Electronic compounds refer to a class of compounds whose crystal structure is determined by the main electron concentration, also known as the Hume-Rossery phase.
Where the electron concentration is the same, the phases have the same type of crystal structure. - Isomers
Different crystal structures formed due to different thermodynamic conditions with the same chemical composition. - Recrystallization temperature
The lowest temperature at which deformed metal just completes recrystallization within a certain period of time (usually 1 hour). - Braffi dot matrix
In addition to considering the shape of the unit cell, the lattice formed by the position of the lattice points is also considered. - Coordination polyhedron
The polyhedron formed by the center lines of atoms or ions surrounding an atom or ion that are directly adjacent to it is called an atom.
Or a coordination polyhedron of ions. - Schmidt factor
Also known as the orientation factor, it is cosΦcosλ, Φ is the angle between the slip surface and the central axis of the external force F, λ is the slip direction and
The angle between the external force F. - Topological close-packed phase
A type of intermediate phase composed of two metal atoms of different sizes, in which the large and small atoms form a void through appropriate coordination.
Complex structures with high space utilization and coordination number. Because this type of structure has topological characteristics, these phases are called topological close packing.
Mutually. - Interstitial compounds
When the ratio of non-metal (X) and metal (M) atomic radii rX/rM>0.59, a complex crystal structure is formed.
phase, often called interstitial compounds. - High angle grain boundary
The grain boundaries between grains in polycrystalline materials are called high-angle grain boundaries, that is, grain boundaries where the phase difference between adjacent grains is greater than 10º. - Small angle grain boundaries
The phase difference between adjacent sub-grains is less than 10º. The grain boundaries between such sub-grains are called low-angle grain boundaries, which are generally less than 2
º, can be divided into inclined grain boundaries, twisted grain boundaries, coincident grain boundaries, etc. - Critical shear stress
The slip system is the minimum shear stress required for operation; it is a fixed value, related to the properties of the material itself, and has nothing to do with the orientation of external forces.
close. China factory manufacture precision dental equipment parts