Small specimen mechanical testing is an exciting and rapidly developing field in which fundamental deformation behaviours can be observed from experiments performed on comparatively small amounts of material. These methods are particularly useful when there is limited source material to facilitate a sufficient number of standard specimen tests, if any at all. Such situations include the development of new materials or when performing routine maintenance/inspection studies of in-service components, requiring that material conditions are updated with service exposure. The potentially more challenging loading conditions and complex stress states experienced by small specimens, in comparison with standard specimen geometries, has led to a tendency for these methods to be used in ranking studies rather than for fundamental material parameter determination. Classifying a specimen as ‘small’ can be subjective, and in the present work the focus is to review testing methods that utilise specimens with characteristic dimensions of less than 50 mm. By doing this, observations made here will be relevant to industrial service monitoring problems, wherein small samples of material are extracted and tested from operational components in such a way that structural integrity is not compromised. Whilst recently the majority of small specimen test techniques development have focused on the determination of creep behaviour/properties as well as sub-size tensile testing, attention is given here to small specimen testing methods for determining specific tensile, fatigue, fracture and crack growth properties. These areas are currently underrepresented in published reviews. The suitability of specimens and methods is discussed here, along with associated advantages and disadvantages.

小样本机械测试是一个令人兴奋且快速发展的领域，在该领域中，可以从对相对少量材料进行的实验中观察到基本的变形行为。当源材料有限以促进足够数量的标准样本测试（如果有的话）时，这些方法特别有用。此类情况包括新材料的开发或对在役组件进行例行维护/检查研究时，要求材料条件随着服务暴露而更新。与标准试样几何形状相比，小试样可能面临更具挑战性的载荷条件和复杂的应力状态，导致将这些方法用于排名研究而不是用于基本材料参数确定的趋势。将样本归类为“小”可能是主观的，在目前的工作中，重点是审查使用特征尺寸小于 50 毫米的样本的测试方法。通过这样做，这里进行的观察将与工业服务监控问题相关，其中从操作组件中提取和测试小样本材料，以确保结构完整性不受损害。虽然最近大多数小试样测试技术的发展都集中在蠕变行为/特性的确定以及小尺寸拉伸测试上，但这里关注的是用于确定特定拉伸、疲劳、断裂和裂纹扩展特性。这些领域目前在已发表的评论中代表性不足。此处讨论了样本和方法的适用性以及相关的优缺点。