This standard is applicable to the determination of the inhalation rate and inhalation volume of non-evaporable getter materials and products such as zirconium-aluminum alloy powder for gettering, zirconium-aluminum alloy rings and sheets for gettering, zirconium-aluminum alloy composite strips for gettering, composite strips for mercury-releasing gettering, and zirconium-graphite materials and products for room temperature gettering. GB/T 8763-1988 Test method for inhalation performance of non-evaporable getter materials and products GB/T8763-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Non-evaporable gettering materials and products
Test methods of gas absorption characteristic fornon-evaporation gettering materials and productsUDC 620.38
.032.1
GB8763--88
This standard is applicable to the determination of the gas absorption rate and gas absorption volume of non-evaporable gettering materials and products such as zirconium-aluminum alloy powder for gas absorption, zirconium-aluminum alloy rings and sheets for gas absorption, zirconium-aluminum alloy composite strips for gas absorption, composite strips for mercury-releasing gettering, and zirconium graphite materials and products for room temperature gettering.
1 Principle
The "constant pressure method" is adopted. When the test vacuum system is in the molecular flow state, the gas flows through the flow conductance element with known conductance. Due to the gas absorption effect of the getter material, a pressure difference appears at both ends of the flow conductance element. Keep the pressure at one end constant and measure the pressure change at the other end over time. The suction rate and suction volume can be calculated.
2 Instruments and equipment
2.1 Vacuum system
The vacuum system is shown in Figure 1.
Figure 1 Schematic diagram of the vacuum system of the tester
1---A gauge; 2-air inlet chamber, 3-flow guide element, 1-suction chamber, 5-sample; 6-high frequency heating coil; 7-ultra-high vacuum valve, 8-thermocouple wire: 9-diffusion pump, 10-mechanical pump; 11-electric plane fine-tuning valve China Nonferrous Metals Industry Corporation approved on February 4, 1988 392
Implementation on February 1, 1989
The diameter of the vacuum ball is 100~160mm.
GB8763—88
The conductance value of the conductance element should be selected based on the maximum air intake rate of the sample in the air intake chamber Pm≤1.3×10-2Pa. System leakage rate; <4×10Pacm/s.
Pressure constant accuracy of the air intake chamber (P,): ≤±1%. Working background pressure of the air intake chamber: <7×10-Pa. Precision of constant heating temperature of the sample: ≤±1%. Reproducibility of the air intake rate measurement of the sample (expressed as relative standard deviation): ≤5%. 2.2 Spot welding machine
2.3 Stopwatch
2.4 Ultra-high vacuum gauge
Range: 10-2～10-Pa.
Response time: 0.1 s.
Send to the metrology department for calibration regularly.
2.5 Heating system
Sample heating method: high-frequency induction heating. Temperature control range: 20～1200℃.
Temperature constant accuracy: ±1% from room temperature to 1200℃. Heating rate: 1℃/s, 1.5℃/s, 3℃/s, optional. 2.6 Pressure automatic control system
Pressure constant accuracy ±1%.
2.7 Vernier caliper
Reading accuracy 0.02mm.
2.8 Tool microscope
Magnification 30 times, reading accuracy 0.001mm. 2.9 Analytical balance
Balance of ten thousandths, weighing accuracy 0.1mg. 3 Test gas
Hydrogen: purity 99.999%.
Nitrogen: purity 99.999%.
Carbon monoxide: purity 99.5%.
4 Sample preparation
4.1 Strip sample preparation: Select a strip with a length of 50~64mm and a width of 6~10mm, remove the powder layer at the overlapped part, weld it into a ring with a spot welder, spot weld a thermocouple wire with a diameter of no more than 0.3mm at the part without powder layer, and spot weld the sample or mount it on a nickel rod. The thermocouple wires are connected to the compensation lead-out rods made of the same material. 4.2 Preparation of ring and sheet specimens: For rings and sheets of different sizes, select an appropriate area, and spot weld the thermocouple wire and the supporting nickel rod directly at the powder-free layer to make the specimen.
4.3 Preparation of hot-sub and columnar specimens: symmetrically spot weld the thermocouple wires on the nickel belt (nickel belt width 1.5mm) that tightly wraps the specimen, and connect the thermocouple wire and hot-sub lead wire to the hot wire lead rod and the electrode rod respectively. 4.4 Use a vernier caliper or tool microscope to measure the specimen size to calculate the surface area, and the area error should not be greater than 1%; or use an analytical balance to weigh the specimen, and the weighing error should not be greater than 1%. 4.5 During the sample preparation process, the operator should wear white clean fine-wire gloves or nylon gloves, and the tools, measuring tools and test environment used should meet the vacuum hygiene requirements to prevent the specimen from being contaminated. 5 Test
5.1 Test preparation
GB 8763---88
5.1.1 Seal the sample into the sample chamber. The position of the sample must not be directly opposite the air flow inlet. 5.1.2 Start the mechanical recorder and evacuate the system. When the pressure drops to about 1Pa, start the diffusion pump. 5.1.3 When the system is evacuated to 6×10'Pa, perform a leak test. 5.1.4 Start the oven to bake the system. The baking temperature is 340±20℃ and the constant temperature time is 4h. 5.1.5 Stop baking and heat the BA gauge to degas. 5.1.6 When the system is evacuated to the desired background pressure, close the vacuum valve connected to the test ball and measure the leakage rate of the suction chamber. If it meets the requirements, open the bottom valve, evacuate the system to the desired background pressure, and prepare for the test. 5.2 Test conditions
5.2.1 Test conditions for aluminum getter materials and products: Constant value of getter chamber pressure (P): 4×10\*Pa for Nz, CO and H; Activation temperature: 900°C; Activation time: 1min; Working temperature: 400 ().
5.2.2 Test conditions for zircon getter materials and products: Constant value of getter chamber pressure (P): 4×10-*Pa for Nz, CO and H; Activation temperature: 900°C; Activation time: 10min; Working temperature: 25°C.
5.2.3 Test conditions for other non-evaporable getter materials and products: Execute in accordance with relevant product standards or be determined by negotiation between the supply and demand parties. 5.3 Test steps
5.3.1 Start the high-frequency heating system, and under the condition that the pressure of the suction chamber is not greater than 1×10-Pa, the sample is uniformly raised and activated according to the specified conditions, and then the sample temperature is reduced to the working temperature. 5.3.2 Start the pressure automatic controller, set the suction chamber pressure at the specified value, start the air intake switch, and set the suction chamber pressure (P) at the specified value within 45s, and start recording the change of the intake chamber pressure (Pm). In the first 1min, read the number every 15s; in 1~5min, read the number every 30s; in 5~30min, read the number every 1min, and after 30min, read the number every 5min until the end of the test.
5.3.3 The sample suction rate is the average of the three test results. 6 Calculation
Calculate the suction rate S (cm/s) according to formula (1): 6.1
F(Pm-P)
Wherein, inlet chamber pressure, Pa
P. suction chamber pressure, Pa
F. conductance, cm/s.
6.2 Calculate the inhaled volume (cmPa) in a certain time t according to formula (2): Q
武; F--
flow conductance, cm2/s;
F(Pm -- P)At
. (1)
P.--intake chamber pressure, Pa;
P.--inhalation chamber pressure, Pa;
N time interval, s
GB8763-88
6.3 The inhalation rate S and the inhalation volume Q must be expressed in the test report as the specific inhalation rate s (cm/scm or cm/s?mg) and the specific inhalation volume Q (cm'Pa/cm or cm'Pa/mg). The test report must give the inhalation rate S in the next minute. 。 6.4 Drawing of St characteristic curve
Use the suction rate value (S) as the ordinate and the suction time (t) as the abscissa to draw the St characteristic curve. Indicate on the upper right corner of the curve: Sample name:
Activation temperature:
P. Constant value: bzxZ.net
Measured gas name:
6.5S-Q characteristic curve drawing
Test time:
Activation time:
Working temperature:
Sample area:
cm2 (or weight mg)
Use the suction rate value (S) as the ordinate and the suction volume (Q) as the abscissa to draw the SQ characteristic curve. Indicate on the upper right of the curve: Sample name:
Activation temperature:
P. Constant value:
Name of the measured gas:
Additional instructions:
Test time:
Activation time:
Working temperature:
Sample area:
cm2 (or weight mg).
This standard was drafted by Beijing General Research Institute of Nonferrous Metals. Yang Bangjun was the main drafter of this standard.
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