This standard specifies the method for determining the dimensional changes of metal powders associated with molding and sintering. This method is applicable to the determination of three dimensional changes associated with the molding and sintering of metal powders (excluding powders for cemented carbide). A. From the die cavity size to the green compact size (elastic aftereffect): After the green compact is released from the die cavity, its size increases in the direction perpendicular to the applied pressure. B. From the green compact size to the sintered size (sintering dimensional change): The dimensional change of the object due to sintering. C. From the die cavity size to the sintered size (total dimensional change). GB/T 5159-1985 Method for determining the dimensional changes of metal powders (excluding powders for cemented carbide) associated with molding and sintering GB/T5159-1985 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Metal powders, excluding powders for hardmetals-Determination of dimensional changes associatedwith compacting and sintering UDC669-492.2
GB5169-85
This standard specifies the determination method of dimensional changes associatedwith compacting and sintering of metal powders. This method is applicable to the determination of three dimensional changes associatedwith compacting and sintering of metal powders (excluding powders for hardmetals). 8. From the center of the die cavity to the smallest dimension (elastic aftereffect); after the object is ejected from the die cavity, the dimension is the largest in the vertical direction of the pressure applied.
From the compacted dimension to the sintered dimension (sintering dimension change): the dimensional change of the object due to sintering. b.
From the cavity dimensions to the sintered dimensions (total dimensional change). c
Pressure metal powder or powder uniformly mixed with additive elements (including lubricants) to form a crushed ring. Sinter the ring under specified conditions. Measure the dimensions of the cavity, crushed and (or) sintered silk samples. Calculate the dimensional change and express it as a white fraction. 2 Equipment
2.1 Die
Prepare cylindrical, rectangular samples or similar → actual parts. 2.2 Press
Can smoothly apply pressure to the required crushed density. 2.3 Balance
Capable of weighing at least 100g with an accuracy of ±0.01g. 2.4 Dimension measuring instrument
Micrometer or other suitable measuring instrument with an accuracy of ±0.005mm. 2.5 Sintering device
Conforms to the specified sintering conditions (time, fluidity, etc.). 3 Steps
3.1 Sampling: Take at least three crushed test powders in acceptance status for each batch. 3.2 Measure the size d (diameter or length) of the mold cavity with an accuracy of 0.005mm. 3.3 Press the metal powder or the powder mixed with added elements (including lubricants) according to the specified crushing radius or molding pressure, and measure the crushing cavity size dc (diameter or length) with an accuracy of 0.005mm3.4 Sinter the powder according to the specified sintering conditions (time, humidity, and atmosphere), and measure its size ds with an accuracy of n.005mma. The sintering sample size should be measured at the same position of the measuring scale. Issued by the National Bureau of Standards on May 8, 1985
Implemented on February 1, 1986
Result Expression
GB 5159-86
4.1 The dimensional change is expressed in percentage and is calculated by the following formula: Crushing dimensional change (elastic aftereffect)Www.bzxZ.net
Where: Adus-
Elastic aftereffect, % (+)
Mold cavity size, mms
d.——- Crushing size, mm.
b Sintering dimensional change (positive or negative)
Where: Adcs
Sintering dimensional change, % (+, ~),
Sintering sample size, mm.
Total dimensional change (positive or negative)
Where: Adsu
Total dimensional change, % (→, -).
ds-de
4.2 The test report shall be the average value of at least three samples and rounded to 0.01%. 5 Test report
The test report shall include the following:
This standard number:
Any details required for the identification of the test powder; the type of crushed specimen and its pressing details, sintering details:
Details of dimensional measurement and density measurement of crushed and sintered specimens, test results obtained,
Operations not specified in this standard or considered to be additional; Details of any phenomena that may affect the test results. Additional notes:
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China and China Nonferrous Metals Industry Corporation. This standard was drafted by the Iron and Steel Research Institute of the Ministry of Metallurgical Industry and the Beijing Powder Metallurgy Research Institute. The main drafters of this standard are Jiang Zhenchun, Wu Rongwei, Zheng Shuying and Cao Baoxing. (1)
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