定价： 646元 加购物车

定价： 571元 加购物车

定价： 571元 加购物车

定价： 571元 加购物车

This specification covers the requirements of a stop-leak additive to function effectively in automobile and light duty service. The stop-leak is intended to seal small leaks in engine cooling systems without adversely affecting heat transfer and fluid flow. The hole plugging capability, and foaming tendency of the stop-leak additive shall be tested to meet the requirements prescribed.1.1 This specification covers the requirements of a stop-leak additive to function effectively in automobile and light duty service. The stop-leak is intended to seal small leaks in engine cooling systems without adversely affecting heat transfer and fluid flow.1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 加购物车

1.1 This standard serves as a guide to existing standards or variations of existing standards that may be applicable to determine specific mechanical properties of materials made with an additive manufacturing process.1.2 As noted in many of these referenced standards, there are several factors that may influence the reported properties, including material, material anisotropy, method of material preparation, porosity, method of specimen preparation, testing environment, specimen alignment and gripping, testing speed, and testing temperature. These factors should be recorded, to the extent that they are known, according to Practice F2971 and the guidelines of the referenced standards.1.3 The following standards are not referred to directly in the guide but also have information that may be useful in the testing of metal test specimens made via additive manufacturing: A370, A1058, B211, B348, B557, B565, B724, B769, E3, E6, E7, E290, E467, E468, E837, E915, E1049,E1823, E1942.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 加购物车

1.1 This document provides guidance to designers who are considering the use of metal Laser Powder Bed Fusion (PBF-LB) method for their products. This guide outlines the following post-processing operations that can be considered after completion of a build on a metal additive manufacturing system:1.1.1 Powder removal,1.1.2 Thermal post-processing,1.1.3 Build platform removal,1.1.4 Support removal,1.1.5 Machining, and1.1.6 Surface finishing.1.2 The topics of non-destructive testing (NDT) and inspection are beyond the scope of this document as it requires a comprehensive guide in its own right. Also, outside the scope are other metal PBF processes such as powder bed fusion – electron beam (PBF-EB) and hybrid additive manufacturing (methods combining additive manufacturing and subtractive manufacturing technologies in a single machine).1.3 With respect to existing ISO/ASTM standards, this guide is positioned between ISO/ASTM 52910 and process-specific design guidelines such as ISO/ASTM 52911-1.1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 843元 加购物车

3.1 Determining optimal strategies for the measurement and characterization of surface texture is necessary to increase confidence in the assessment of surfaces and in any further comparisons and correlations sought between manufactured surfaces, manufacturing processes, and desired functionality. Further, measurement and characterization of surface texture have implications in the field of tribology and in the determination and specification of part quality. This guide is designed to provide users of measurement technologies in both industry and academia with good practice for optimizing measurements of surfaces produced by metal powder bed fusion (PBF) manufacturing processes. While the focus of this guide is on surfaces produced by metal PBF, some of the referenced methods may also be appropriate for surfaces produced by other manufacturing processes.1.1 This guide is designed to introduce the reader to techniques for surface texture measurement and characterization of surfaces made with metal powder bed fusion additive manufacturing processes. It refers the reader to existing standards that may be applicable for the measurement and characterization of surface texture.1.2 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 646元 加购物车

5.1 General: 5.1.1 This guide is intended to support PBF-LB process and parameter development, part acceptance criteria, and process control tests.5.1.2 Flaws and Defects—Fabricating fully dense parts continues to be a challenge in AM as the process intrinsically introduces volumetric flaws into a part reducing the part relative density (that is, increasing porosity or the presence of small voids in a part making it less than fully dense) and mechanical performance.5.1.2.1 When a flaw reaches a size, shape, location, or criticality that makes it becomes unacceptable for part acceptance, it will be referred to as a defect.5.1.2.2 Flaw or defect formation is governed by the manufacturing process, build parameters, feedstock, and geometric factors. Therefore, accurate measurement of fabricated part relative density is an important initial step in determining part and process quality.5.1.2.3 The quantity, size, and shape of the volumetric flaws influences mechanical performance of a part, particularly under cyclic loading. These data could indicate irregularly shaped (for example, LOF pores or microcracking) or spherical porosity (for example, keyhole or entrapped gas porosity) and determine acceptability by assigning criteria. While these metrics can be quantified, in this guide, the general capabilities of each method to capture this data will be highlighted, but detailed recommendations on these data types will not be made and rather the focus will be on relative density measurements.5.1.3 Uncertainty and Error—Users should consider that each measurement technique considered in this guide has differing sensitivities to various sized features. The measurement methods will also have different potential systematic errors or measurement uncertainties due to sampling sizes, detection resolution, effect of surface condition, experimental set-up, or reliance on a theoretical material density. It is important that these effects are taken into consideration as well as the natural statistical variability in the measurements. Multiple measurements of nominally identical test specimens should be made to enable the quantification of statistical uncertainty. Systematic uncertainty contributions will not be reduced by greater numbers of repeated measurements. When measuring specimens with relative densities close to 100 % quantification of systematic uncertainty for the selected measurement technique(s) becomes more critical to separate measurement and systematic variation from variation driven by the AM process. Differing levels of rigor can be applied when determining the role of uncertainty and variation depending on whether the measurement is in support of process development (for example, identifying appropriate fabrication parameters) or part acceptance (for example, part qualification).5.1.4 Repeatability and Reproducibility—As uncertainty and error can be introduced into the measurement process through operator variation. Performing gage repeatability and reproducibility (Gage R&R), a process that determines a test method’s repeatability and reproducibility, is recommended for methods that rely on significant manual specimen preparation or operation such as Archimedes, pycnometry, ultrasonic, and metallography. Refer to Guide E2782 for guidance on performing this process evaluation.5.2 Method Selection: 5.2.1 When evaluating methods, it may be beneficial to understand how the various attributes compare from method to method. In Fig. 1, a summary matrix comparing these various methods and their qualities is given.FIG. 1 Comparison Matrix of the Test Methods Evaluated in This Guide5.2.2 Using Multiple Methods—It can be desirable to use multiple methods to determine relative density. For example, using low-resolution XCT to measure larger part flaws and metallography to identify the quantity of smaller process flaws could prove to be a highly useful way of producing accurate flaw data. Another approach to strengthen measurement accuracy is by implementing multiple methods that operate on similar principles, such as pycnometry and Archimedes.5.2.3 Non-destructive Methods—Archimedes, ultrasonic, pycnometry, and XCT are nondestructive methods, while metallographic methods require part destruction to get relative density measurements. All the nondestructive methods can be used to characterize part relative density; however, as part size increases, these methods can become cumbersome to use. Archimedes requires a much larger and dedicated setup for relative density calculation that can be expensive for the appropriate accuracy but remains the least cost-intensive option, XCT and ultrasonic results are highly geometry and size dependent, and many pycnometry devices cannot handle larger part volumes (many pycnometers are equipped to handle specimen volumes of 1 cm3 to 3.5 cm3, however there are some that can handle up to 10 cm3). While several of these methods may not be suitable for characterizing larger part volumes, all can provide relative density. Low-cost and quick measurement methods, such as Archimedes, can be used as a means of process development or data for statistical process control during production.5.2.4 Pore Morphology Data—Metallographic and XCT methods can provide relative density measurements and specific geometric details (that is, size, aspect ratio, and shape) of individual flaws in addition to the overall part relative density. However, metallographic and XCT measurements are highly dependent on the resolution of the data, whether that is the sections examined, quantity of images, or microscope resolution, or a combination thereof, for metallographic methods or voxel size used for XCT. Archimedes, ultrasonic, and pycnometry methods do not provide these types of data when measuring relative density.5.2.5 Relative Density Measurements Relying on Theoretical Material Density—Archimedes, ultrasonic, and gas pycnometry methods rely on theoretical material density values in the calculation of relative density. The theoretical material density value selected is a possible source of systematic error. Material density is composition dependent. Each material will have a compositional specification and an allowable variation of that composition. This combined with material vaporization during fabrication could lead to a different material density value than the reported value by a material vendor or online source. The user should use caution on the reliance of a reported value and ensure the theoretical density is representative of the material (that is, from the specific material lot, measured from final material, or from a reliable database such).5.2.5.1 For methods relying on comparing the measured and theoretical material densities to calculate the relative density of the specimen, the following formula should be used:5.3 Method Specific Recommendations: 5.3.1 Archimedes Method—The Archimedes method is highly cost effective, nondestructive, and relatively non-geometry dependent; however, a significant amount of variation can be introduced into the process from the operator, part size, surface finish of the part, fluid entrapment, evaporation of fluid, temperature, water purity, absorbed gases, surface pores or cracks, and bubbles. Uncertainties of approximately 0.1 % for relative density measurements can be achieved for fully dense materials using this method. The sources of variation combined with part size will increase this uncertainty. However, training and consistent practices can minimize the effects of variation between measurements. Additionally, there are two main ASTM International standards for Archimedes measurements, Test Methods B962 and B311. Test Method B311 is specifically designed for measuring material density of parts with less than 2 % porosity volume and is, therefore, recommended as the measurement method for PBF-LB parts. The major difference between the two methods is that Test Methods B962 require fluid impregnation to deal with surface-connected porosity and Test Method B311 does not. If a specimen increases in mass while submerged in water, use Test Methods B962, and if the specimen does not gain mass, then Test Method B311 is applicable. Agitating the PBF-LB specimens while submerged is recommended to reduce any air pockets that may exist on the part’s surface. Additionally, a benefit of AM is the ability to achieve high complexity—a potential source of error using this method would be internal channels or the ability for the liquid to cover the entire volume. It is recommended to take multiple measurements when using this method and compute a standard deviation.5.3.2 Gas Pycnometry Method—Gas pycnometry requires that specimens be free of contaminants that may outgas during the test, shall not react with the displacing gas, and shall have sufficient strength to avoid deformation in the pressurized gas environment. Additionally, this method should only be used to measure parts with high relative densities since this method uses a gas to determine volume. Specimens with surface porosity or interconnected pore structures (whether through process defect or by design) will measure the skeletal volume, resulting in an inaccurate relative density measurement. This method functions on similar principles to that of Archimedes; however, it does not possess as many potential sources of error related to using a liquid for volume displacement. Uncertainty in this method is a function of part size and equipment capacity. There are several equations to calculate uncertainty from the equipment manufacturer; however, it will be equipment and part specific. Note that pycnometry determines a volume that can be compared directly to theoretical part volume based upon CAD dimensions of the part being produced. Differences can point directly to the volume of closed porosity in the produced part. Test Method B923 is used for measurement of skeletal or material density. While this test method is primarily for determination of skeletal density of metal powders, it has also been found to be useful for determination of skeletal volume and density of parts produced by traditional powder metallurgy methods. Note that it is best to try to choose a pycnometer capacity and specimen container configuration that result in the specimen under test occupying as much of the specimen container volume as possible. It can occur that a produced part is too large for any commercial gas pycnometers, and if so, another listed method shall be selected. Multiple measurements should be taken when using this method and compute a standard deviation.5.3.3 Ultrasonic Method—Ultrasonic relative density characterization is limited in application by part geometry and suffers errors induced by small part sizes and surface roughness inherent in AM parts. Larger specimen parts with simple geometries (for example, cubes) and polished surfaces to measure from should be used for data capture. Note that this method is typically used as an NDT method and not for relative density measurement. Changes in measured velocity can be indicative of cracking or flaws within parts. These data received through ultrasonic testing can be evaluated into several equations provided in Practice E494 to calculate material density. This can then be compared to theoretical material density to compute a relative density measurement. However, several material constants such as Poisson’s ratio or Young’s modulus are required. To determine accurate values, additional testing is required, which can be cumbersome. Otherwise, vendor or online sources may need to be used to estimate these values, which may not be representative of the true values or include uncertainty considerations. Because of these factors combined with measurement variability inherent to measuring as-built AM parts, this is not a preferred method for measuring relative density of PBF-LB parts.5.3.4 XCT Method—XCT provides highly descriptive data, such as pore size, shape, and distribution. However, it does require costly equipment and is time intensive. High-resolution (voxel size of ~1 µm to 5 µm) analysis is obtainable using XCT; however, there is a limitation on specimen size, requiring smaller parts, longer scanning times, and often more cost. Low resolution XCT can evaluate larger parts but is unable to detect fine details or smaller flaws. Successful parameters and software processing steps should be recorded to ensure repeatability. Additionally, the software tools used to filter noise and the grayscale thresholding can lead to uncertainty and variation as some pores can be missed in the analysis. Significant iterating may be required to find the proper scanning and processing parameters and operators should be trained. Resolution is governed by voxel size in this method; however, uncertainty can arise from this as well. Smaller gas pores can be unaccounted for in relative density computation if a larger voxel size is selected. Additionally, the thresholding criteria selected for identifying pores are another source of error.5.3.5 Metallography and Serial Sectioning Method—Metallurgical examination of porosity requires mechanical sectioning of the part or test specimen and an apparatus such as described in Practice E1245, a light microscope equipped with brightfield objectives and digital imaging. Image analysis software produces a binary image and counts black pixels against a white background or vice versa. This is a relatively low-cost relative density measurement technique. However, as it is a destructive method, it is, therefore, more applicable to test specimens than actual parts in a production setting. If sectioning a production part, examine critical design locations and areas prone to porosity. The microscopic images from which relative density data are derived are 2D and require mathematical relationships of stereology for planar surfaces to determine uncertainty. Multiple images of the full specimen area in several orientations and at multiple polishing depths should be taken when using this method. A significant amount of uncertainty exists within this method from systematic and sampling sources. Critical pores can be missed as the whole specimen is not measured. Another method, such as pycnometry, should be used to generate reliable relative density measurements of a specimen. Automated serial sectioning and imaging allows for expansive data collection that captures a significant number of micrographs from a specimen using metallurgical methods. However, the capital equipment involved and time to generate a large quantity of images makes this method costly. Serial sectioning images can be stitched in the polishing direction to render high resolution 3D data of the specimen. Serial sectioning can be used to reduce the uncertainty of the metallographic method by taking a large quantity of image data. Special care should be taken during the specimen preparation procedure to ensure minimal residual scratching.1.1 In this standard, guidelines for measuring post-manufacturing relative density of metallic additive manufactured (AM) parts and density assessment test specimens are given.1.2 In this guide, standard test methods commonly used to measure part relative density and details any procedural changes or recommendations for use with PBF-LB parts are referenced. Extensibility to other types of metallic AM processes may be considered on a case-by-case basis with user discretion.1.3 This guide is intended to be applied during the selection process of methods to measure the relative density of AM parts to balance cost, accuracy, complexity, part destruction, and part size concerns.1.4 Pore size, shape, and distribution and their implications relative to the AM process and material are beyond the scope of this guide; however, each method’s ability to obtain these metrics is discussed in the context of the various density measurement methods.1.5 Units—The values stated in SI units are to be regarded as the standard. No other units of measurement are included in this standard.1.6 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 加购物车

This document specifies the features of laser-based powder bed fusion of metals (PBF-LB/M) and provides detailed design recommendations.Some of the fundamental principles are also applicable to other additive manufacturing (AM) processes, provided that due consideration is given to the process-specific features.This document also provides a state of the art review of design guidelines associated with the use of powder bed fusion (PBF) by bringing together relevant knowledge about this process and by extending the scope of ISO/ASTM 52910.

定价： 646元 加购物车

5.1 DRA is frequently added into multiproduct pipelines to increase throughput or reduce energy requirements of fuel movement. Although these additives are not used in jet fuel, contamination can occur from other products if proper batching guidelines are not followed or by other cases of human error. CRC Report No. 642 reviewed the impact of DRA on jet fuel fit-for-purpose performance and concluded that the fuel spray angle and atomization capability of several engine-type fuel nozzles can be adversely affected impacting high altitude relight performance at elevated concentrations. A method that accurately quantifies the amount of DRA in jet fuel can be useful in confirming the absence of significant contamination to protect the safety of aviation operations. This test method is designed to measure down to sub-100 µg/L levels of DRA in aviation fuel.1.1 This test method covers the measurement of high molecular weight polymers, in particular pipeline drag reducer additive (DRA), in aviation turbine fuels with a 72 µg/L lower detection limit. The method cannot differentiate between different polymers types. Thus, any non-DRA high molecular weight polymer will cause a positive measurement bias. Further investigation is required to confirm the polymer detected is DRA.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 Warning—Mercury has been designated by many regulatory agencies as a hazardous substance that can cause serious medical issues. Mercury, or its vapor, has been demonstrated to be hazardous to health and corrosive to materials. Use Caution when handling mercury and mercury-containing products. See the applicable product Safety Data Sheet (SDS) for additional information. The potential exists that selling mercury or mercury-containing products, or both, is prohibited by local or national law. Users must determine legality of sales in their location.1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 加购物车

1.1 This specification covers formulating specifications for purchases of an unleaded aviation gasoline test fuel under contract and is intended solely for use by purchasing agencies for testing purposes.1.2 This specification defines a specific type of aviation gasoline for use as an aviation spark-ignition engine test fuel. It does not include all gasolines satisfactory for reciprocating aviation engines. Certain equipment or conditions of use may permit a wider, or require a narrower, range of characteristics than is shown by this specification.1.3 The unleaded aviation gasoline test fuel defined by this specification does exhibit similar octane performance to those leaded fuels with which the existing aircraft and ground-based fuel handling equipment have been designed to operate.1.4 Issuance of this specification does not constitute approval to operate certificated aircraft with this test fuel. Fuels used in certified engines and aircraft are ultimately approved by the certifying authority subsequent to formal submission of evidence to the authority as part of a certification program.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.6 This specification, unless otherwise provided, prescribes the required properties of unleaded aviation gasoline test fuel at the time and place of delivery.1.7 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 加购物车

定价： 927元 加购物车

定价： 712元 加购物车

定价： 712元 加购物车