81.060.99 (Other standards related to ceramics); 8 标准查询与下载

ASTM C1211-13 高温下高级陶瓷抗弯强度的标准试验方法

4.1 This test method may be used for material development, quality control, characterization, and design data generation purposes. This test method is intended to be used with ceramics whose flexural strength is ∼ 50 MPa (∼ 7 ksi) or greater. 4.2 The flexure stress is computed based on simple beam theory, with assumptions that the material is isotropic and homogeneous, the moduli of elasticity in tension and compression are identical, and the material is linearly elastic. The average grain size should be no greater than 1/50 of the beam thickness. The homogeneity and isotropy assumptions in the test method rule out the use of it for continuous fiber-reinforced composites for which Test Method C1341 is more appropriate. 4.3 The flexural strength of a group of test specimens is influenced by several parameters associated with the test procedure. Such factors include the testing rate, test environment, specimen size, specimen preparation, and test fixtures. Specimen and fixture sizes were chosen to provide a balance between the practical configurations and resulting errors as discussed in Test Method C1161, and Refs (1-3).4 Specific fixture and specimen configurations were designated in order to permit the ready comparison of data without the need for Weibull size scaling. 4.4 The flexural strength of a ceramic material is dependent on both its inherent resistance to fracture and the size and severity of flaws. Variations in these cause a natural scatter in test results for a sample of test specimens. Fractographic analysis of fracture surfaces, although beyond the scope of this test method, is highly recommended for all purposes, especially if the data will be used for design as discussed in Ref (4) and Practices C1322 and C1239. 4.5 This method determines the flexural strength at elevated temperature and ambient environmental conditions at a nominal, moderately fast testing rate. The flexural strength under these conditions may or may not necessarily be the inert flexural strength. Flexure strength at elevated temperature may be strongly dependent on testing rate, a consequence of creep, stress corrosion, or slow crack growth. If the purpose of the test is to measure the inert flexural strength, then extra precautions are required and faster testing rates may be necessary. Note 6—Many ceramics are susceptible to either environmentally-assisted slow crack growth or thermally activated slow crack growth. Oxide ceramics, glasses, glass ceramics, and ceramics containing boundary phase glass are particularly susceptible to slow crack growth. Time dependent effects that are caused by environmental factors (e.g. water as humidity in air) may be minimized through the use of inert testing atmosphere such as dry nitrogen gas or vacuum. Alternatively, testing rates faster than specified in this standard may be used if the goal is to measure the inert strength. Thermally activated slow crack growth may occur at elevated temperature even in inert atmospheres. Testing rates faster than specified in this standard should be used if the goal is to measure the inert flexural strength. On the other hand, many ceramics such as boron carbide, silicon carbide, aluminum nitride and many silicon nitrides have no sensitivity to slow crack growth at room or moderately elevated temperatures a......

Standard Test Method for Flexural Strength of Advanced Ceramics at Elevated Temperatures

ASTM C1466-00(2012) 用石墨原子反应堆吸收光谱法测定陶瓷食品器皿中铅和镉的标准试验方法

Toxic effects of lead and cadmium are well known and release of these elements from foodware is regulated by many countries. Regulatory decisions are based on results of 24-h leaching with acetic acid because results of this test method are precise and accurate and this test method is easy to use. Concentrations of lead and cadmium extracted by food may be different from results of this method, however, because acidity, contact time, and temperature typical of consumer use are different from those of this test method. This test method is intended for application only in contamination-free settings and should be performed by well-qualified technical personnel. It is recognized that it is not a practical or appropriate method to use in a nonlaboratory environment for quality assurance and control of the ceramic process. Users are advised to use Test Method C738 (flame AAS) for purposes of the latter.1.1 This test method covers procedures for using graphite furnace atomic absorption spectroscopy (GFAAS) to quantitatively determine lead and cadmium extracted by acetic acid at room temperature from the food-contact surface of foodware. The method is applicable to food-contact surfaces composed of silicate-based materials (earthenware, glazed ceramicware, decorated ceramicware, decorated glass, and lead crystal glass) and is capable of determining lead concentrations greater than 0.005 to 0.020 μg/mL and cadmium concentrations greater than 0.0005 to 0.002 μg/mL, depending on instrument design. 1.2 This test method also describes quality control procedures to check for contamination and matrix interference during GFAAS analyses and a specific sequence of analytical measurements that demonstrates proper instrument operation during the time period in which sample solutions are analyzed. 1.3 Cleaning and other contamination control procedures are described in this test method. Users may modify contamination control procedures provided that the modifications produce acceptable results and are used for both sample and quality control analyses. 1.4 The values stated in SI (metric) units are to be regarded as the standard. The values given in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Standard Test Method for Graphite Furnace Atomic Absorption Spectrometric Determination of Lead and Cadmium Extracted from Ceramic Foodware