GB/T 4740-1999 Test method for compressive strength of ceramic materials

This standard specifies the test equipment, specimens, test procedures, result calculation and data processing of the compressive strength of sintered ceramic materials at room temperature. This standard is applicable to sintered ceramic materials and auxiliary materials. GB/T 4740-1999 Test method for compressive strength of ceramic materials GB/T4740-1999 Standard download decompression password: www.bzxz.net

GB/T 4740-1999
This standard is a revision of GB/T4740-1984 in accordance with GB/T1.11993 (Guidelines for Standardization Unit 1: Drafting and Expression Rules of Standards Part 1: Basic Regulations for Standardization). The main technical differences between this standard and GB/T4740-1984 are as follows: The structure, technical elements and expression rules of the standard have been modified in accordance with GB/T1.1-1993. According to scientific and applicable requirements, the conditions of the testing machine are specified. The drying part of the sample is added. This standard is recommended to replace GB/T4740-1984 from the date of implementation. This standard is proposed by the State Bureau of Light Industry.
This standard is under the technical jurisdiction of the National Ceramic Standardization Center. The responsible drafting unit of this standard: Ceramic Research Institute of China Light Industry Association. The main drafters of this standard: Zhang Pei, Xu Lihua, Cheng Dianxian. 72
1 Scope
National Standard of the People's Republic of China
Standard test method for compressiveresistance of ceramic materialsGB/T 4740---1999
Replaces GB/T4740--1984bZxz.net
This standard specifies the test equipment, specimens, test procedures, result calculation and data processing for the compressive strength of ceramic sintered materials at room temperature.
This standard applies to sintered ceramic materials and auxiliary materials. 2 Definitions
This standard adopts the following definitions.
Compressive strength
The ultimate load that a material can withstand per unit area. 3 Equipment
3.1 Testing machine
3.1.1 The pressure when the specimen is fully crushed is between 10% and 90% of the testing machine's range. 3.1.2 The relative error is not more than 1%, and the load can be applied at a constant speed. 3.1.3 One of the pressure plates is equipped with a spherical seat, which can compensate for slight deviations in parallelism between the pressure surface of the specimen and the pressure plate. 3.2 The oven
Can be kept warm at 110℃±5℃. ||tt ||3.3 Vernier caliper
The precision is 0.02mm.
3.4 ​​Dryer
4 Samples
4.1 10 samples with a diameter of 20mm±2mm and a height of 20mm±2mm (diameter of stoneware sample is 50mm±5mm and height is 50mm±5mrn).
4.2 The preparation of the sample adopts the same process as the actual production of the material. 4.3 The two bottom surfaces of the sample are processed and regularized on the grinding machine with No. 100 diamond abrasive. The non-parallelism of the two bottom surfaces is less than 0.01mm/mm, and the non-verticality between the sample generatrix and the bottom surface is less than 1°. 4.4 The sample should have no obvious defects and a clean surface. 5 Test steps
5.1 Place the sample in an oven at a temperature of 110℃ and dry it for 2h, then put it in a dryer and cool it to room temperature. 5.2 Measure and record the diameter and height of each sample with an accuracy of 0.1mm. Approved by the State Administration of Quality and Technical Supervision on August 12, 1999, and implemented on February 1, 2000
GB/T 4740—1999
5.3 Place the sample in the center of the test machine's pressure plate, and pad the two pressure-bearing surfaces of the sample with 1mm thick straw board paper. 5.4 Select an appropriate range, and load evenly at a speed of 2×102N/s (1.5×10N/s for coarse pottery) until the sample breaks (the dynamometer pointer turns inverted), and record the maximum load indicated by the test machine. 6 Result calculation and data processing
6.1 The ultimate compressive strength is calculated according to formula (1): a=
Where: .-compressive strength, MPa;
P-the maximum load of the sample under compression and crushing N; D--diameter of the sample, mm.
6.2 Data processing
6.2.1 When the maximum relative deviation is greater than 10%, discard the sample with the largest relative deviation, and then recalculate the remaining values ​​until it meets the requirements. The maximum relative deviation is calculated according to formula (2): R(%) = IAm(or Amm) -Al )
Where:
R—maximum relative deviation, %
Amax (or Amin)-
maximum value (or minimum value);
A——average value.
6.2.2 If the discarded samples reach 4% of the total number of samples, re-samples should be prepared for testing. ×100
6.2.3 The arithmetic mean of the valid samples is used as the compressive strength value of the sample, and the data is rounded to 0.1MPa. 7 Test report
The report should include the following contents:
a) Sample sending unit, sample name, sample number; b) Data discarded, compressive strength value; c) Test date, test personnel, test unit. 74
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.