Development of Small-Scale Mechanical Testing Techniques for Limited Volume Metals
Open Access
- Author:
- Johnson, Andrew
- Area of Honors:
- Materials Science and Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Robert Allen Kimel, Thesis Honors Advisor
Allison Michelle Beese, Thesis Supervisor - Keywords:
- Mechanical Properties
Materials Science
Stainless Steel
Tensile Testing - Abstract:
- Uniaxial tensile testing is a ubiquitous method for determining material strength that has been used since the 18th century. Current metallic tensile testing standard ASTM E8/E8M-16a is used in US industry and academia to ensure test results can be accurately compared between labs and companies. The procedure defined by ASTM E8 provides different sample geometries; however, these may be too large to be used to study samples with limited volume, such as metallic glasses and weld regions. To investigate the ability to measure consistent bulk properties with different sized samples, several miniature tensile test geometries have been designed by researchers. Although material properties are intrinsic, their measurement can be affected by the geometry of samples. In this work, samples of AISI Stainless Steel 304 in five different miniature geometries were tested in a miniature load frame to examine any changes in properties as a function of sample geometry. Samples were deformed to fracture in quasi-static uniaxial tension and strain was measured using digital image correlation. Testing revealed that, with the scope of samples and settings used, miniature samples have higher 0.2 % offset yield, ultimate tensile strength, and elongation at fracture than conventional samples. Elongation at fracture was also shown to increase with the ratio of the square root of initial sample gauge region cross-sectional area to length.