GB/T 15015-1994 Terms and definitions of physical properties and quantities in the field of expansion alloys GB/T15015-1994 standard download decompression password: www.bzxz.net

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Terms and definitions of physical properties and physical quantities in the field of expansion alloys
Physical characters and physical quantities definitions for expansion alloysGB/T15015-94
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This standard applies to the basic theory and technology in the field of expansion alloys. The basic and commonly used terms and definitions of physical properties and physical quantities 1 Linear thermal expansion
Linear thermal expansion
The change in length of an object caused by a change in temperature. The unit name of linear thermal expansion is meter and the unit symbol is m. 2 Linear thermal expansion ratio △L/L
Linear thermal expansion ratio AL/L. The change in unit length of an object caused by a change in temperature. Linear thermal expansion ratio is dimensionless.
3 Mean coefficient of linear thermal expansion
mean coefficient of linear thermal expansion & When an object is at a certain temperature, the average temperature changes by 1℃ and the corresponding linear thermal expansion rate. The expression of the mean linear thermal expansion coefficient & is; a=(L—)/((—,))
Note: In actual measurement, if L is replaced by L, the calculation error caused is much smaller than the measurement error, so L can be used instead of Lo. In the formula, α-
-mean linear thermal expansion coefficient, C-1,
initial temperature of the thermal expansion object, C;
t—final temperature of the thermal expansion object,
L——: length of the object at temperature, m
L,—length of the object at temperature, m;
Lg—length of the object at the reference temperature of 20℃, m. The unit name of the mean linear thermal expansion coefficient is per degree Celsius, and the unit symbol is C-1. 4 Mean volumetric thermal expansion coefficient,
mean coefficient of volurnetric thcrmal expansion a, is the change in unit volume of an object corresponding to a temperature change of 1℃ when the temperature is determined to t. The expression of the average body thermal expansion coefficient &, is: Approved by the Image Technology Supervision Bureau on April 4, 1994 and implemented on May 1, 1994
GB/T 15015 94
a,=(V, -V)/LV,(t2-+)j
Note: In actual measurement, if the calculation error caused by replacing V. by V, is much smaller than the measurement error, V, can be used to replace V. Where: ,——average body thermal expansion coefficient,! "t, — initial temperature of the thermal expansion object, C; t2——- adjusted temperature of the thermal expansion object, C; V, volume of the object at t2 temperature, m\,
Vi-— volume of the object at temperature, m;
V —- volume of the object at reference temperature 20 C, m~. The unit name of the average thermal expansion coefficient is per degree Celsius, and the unit symbol is 亡-1. 5 Average surface thermal expansion coefficient s
tnean coefficient of areal thermal expansionasThe change in unit area corresponding to a temperature change of 1°C when an object is at a certain temperature to: average surface thermal expansion coefficient g The expression is: ag=(S—S)/S(te—)
Note: In actual measurement, if the calculation error caused by S. being replaced by S. is much smaller than the measurement error, S. can be used to replace S. In the formula ... the formula: ag=(S—S)/S(te—)
Note: In the formula: ag=(S—S)/S(te—)
Note: In the formula: ag=(S—S)/S(te—)
Note: In the formula: ag=(S—S)/S(te—)
Note: In the formula: ag=(S—S)/S(te—)||t (—)/(tgt)
Note: In actual measurement, if the calculation error caused by substitution is much smaller than the measurement error, it can be used as a substitute. Wherein: +—
-average linear thermal expansion coefficient, ℃-1,
initial temperature of the thermal expansion object, ℃;
2——final temperature of the thermal expansion object, ℃; ——the circumference length of the object at temperature t2, m, A——the circumference length of the object at temperature t, m —the circumference length of the object at the reference temperature of 20℃, m. The unit name of the average linear thermal expansion coefficient is per degree Celsius, and the unit symbol is ℃1. 7 Instantaneous thermal expansion coefficient α
instantaneous coefficisnt of linear thermal expansion at For an object at a certain temperature, when the temperature changes to zero, the average linear thermal expansion coefficient is the instantaneous linear thermal expansion coefficient at that temperature. The expression of the instantaneous linear thermal expansion coefficient α is: GB/T 15015—94
a,=-lim ((LL)/U(t)))
Note: In actual measurement, if the calculation error caused by L, being replaced by L: is much smaller than the error of the auxiliary quantity, L: can be used to replace L: In the game: a
Instantaneous linear thermal expansion coefficient, C-1;
The initial temperature of the thermal expansion object, C;
The final temperature of the thermal expansion object, C;
The length of the object at temperature L,2, m:
The length of the object at temperature L—t-m;
The length of the object at the reference temperature of 20℃, m. L,
The unit name of the instantaneous linear thermal expansion coefficient is per degree Celsius, and the unit symbol is C-!. 8 Linear thermal expansion force 'F.
Linear thermal expansive forceFThe force exerted on the constrained object when the object is constrained due to its change along the length direction when the temperature changes. The unit name of linear thermal expansion force is Newton, and the unit symbol is N. 9 Thermal expansion stress.
thermal expansive stress d.
The stress generated on the constrained object when the object is constrained due to its expansion when the temperature changes. The unit name of thermal expansion stress is Newton·per square meter, and the unit symbol is N/m. 10 Slip rate 9
permeability rate
The amount of gas passing through the container per unit time. The unit name of leakage rate is Pa [scal] cubic meter per second; the unit symbol is Pa·m/s.11 Air tightness
impermeability
Characterizes the ability of the material to hinder the passage of gas under certain conditions of temperature, air pressure, sealing, etc., and the passband is expressed by leakage rate. 12 Bend point Te (Tn)
bend point
The temperature corresponding to the obvious turning point on the thermal expansion curve. This point corresponds to the Curie point (Tc) or Neel point (Tn) temperature of the material. 13 Invar effect
Invarable effect
The phenomenon that the expansion coefficient of the material produced within a certain temperature range is lower than the normal expansion coefficient. Additional remarks:
This standard was proposed by the Information Standard Research Institute of the Ministry of Metallurgical Industry. This standard was drafted by Northeastern Polytechnic Institute and the Information Standard Research Institute of the Ministry of Metallurgical Industry. This standard is marked with GB/T 15015-941
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