1.1 本试验方法涵盖了确定金属晶体方向的背反射劳厄程序。用于确定晶体取向的背反射劳厄方法可适用于大晶粒和微晶粒，具体取决于多晶聚集体内的光束尺寸，以及任何尺寸的单晶。本试验方法参考立方晶体和其他结构，如:六角形、四方或正交晶体。 1.2 大多数天然晶体的外表面发育良好，通常可以通过检查确定此类晶体的方向。 表面发育不良或完全没有表面的晶体（例如，实验室制备的金属晶体）的取向应通过更精细的方法确定。其中最方便和准确的是使用X射线衍射。当单位晶胞的晶体学轴在空间中的位置已参考晶体试样的表面几何形状确定时，“金属晶体的方向”已知。单元位置和表面几何形状之间的这种关系最方便地用赤平投影或gnomonic投影表示。 1.3 单位- 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。将两个系统的值合并可能会导致不符合标准。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 4.1 金属和其他材料的物理性质通常是各向异性的（例如:杨氏模量通常会在不同的结晶方向上变化）。因此，通常需要或有必要确定单晶的方向，以确定任何相关物理性质与材料中不同方向的关系。 4.2 该试验方法可在商业上用作生产条件下的质量控制试验，其中要求在规定的限制范围内实现所需的方向。 4.3 通过使用可调固定支架（稍后可安装在锯、车床或其他机器上），可以将单晶材料移动到首选方向，然后进行切片、研磨或其他处理。 4.4 如果多晶材料中的晶粒足够大，则该试验方法也可用于确定它们的方向，并且可以记录或绘制方向差异，或者两者兼有。

1.1 This test method covers the back-reflection Laue procedure for determining the orientation of a metal crystal. The back-reflection Laue method for determining crystal orientation may be applied to macrograins and micrograins depending on the beam size within polycrystalline aggregates, as well as to single crystals of any size. This test method is described with reference to cubic crystals and other structures such as: hexagonal, tetragonal, or orthorhombic crystals. 1.2 Most natural crystals have well developed external faces, and the orientation of such crystals can usually be determined from inspection. The orientation of a crystal having poorly developed faces or no faces at all (for example, a metal crystal prepared in the laboratory) shall be determined by more elaborate methods. The most convenient and accurate of these involves the use of X-ray diffraction. The “orientation of a metal crystal” is known when the positions in space of the crystallographic axes of the unit cell have been located with reference to the surface geometry of the crystal specimen. This relation between unit cell position and surface geometry is most conveniently expressed by stereographic or gnomonic projection. 1.3 Units— The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 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. ====== Significance And Use ====== 4.1 The physical properties of metals and other materials are often anisotropic (for example: Young's modulus will typically vary in different crystallographic directions). As such, it is often desirable or necessary to determine the orientation of a single crystal to ascertain the relation of any pertinent physical properties with respect to different directions in the material. 4.2 This test method can be used commercially as a quality control test in production situations in which a desired orientation, within prescribed limits, is required. 4.3 With the use of an adjustable, fixed holder that can later be mounted on a saw, lathe, or other machine, a single crystal material can be moved to a preferred orientation and subsequently sectioned, ground, or processed otherwise. 4.4 If the grains in a polycrystalline material are large enough, this test method can also be used to determine their orientations and differences in orientation can be documented or mapped or both.