Effect of defects and specimen size with rectangular cross-section on the tensile properties of additively manufactured components

ABSTRACT

To evaluate specimen size dependence on the tensile properties of additively manufactured (AM) components, various rectangular specimens, ranging from miniaturised to ASTM standard specimens, are machined from electron beam melted Ti-6Al-4V and used for the tensile testing. It is found that the elongation is strongly related to the sample size while the yield and ultimate tensile strengths exhibit an independent feature. Three major aspects, (i) presented location of lack of fusion, (ii) size and segregation of pores, and (iii) slimness ratio, have a synergic influence on the elongation of different specimen sizes with various cross-section area. Our findings suggest that microscale tests arise uncertainties in measurement, which must be considered in order to provide quantifiable levels of confidence when applying such tests to discriminate a material’s behaviour. The experimental results and analyses provide a guideline for the design and testing of non-standard specimens for AM components.

KEYWORDS:

• 3D printing
• electron beam melting
• elongation
• defects
• lack of fusion

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes on contributors

Dr Pan Wang is in the Singapore Institute of Manufacturing Technology, Singapore.

Min Hao Goh is in the Singapore Institute of Manufacturing Technology, Singapore.

Qiang Li is in the School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai, People's Republic of China.

Mui Ling Sharon Nai is in the Singapore Institute of Manufacturing Technology, Singapore.

Jun Wei is in the Singapore Institute of Manufacturing Technology, Singapore.

Additional information

Funding

The work in the research was financially supported by A*STAR Industrial Additive Manufacturing Program: Work Package 3 (Electron Beam Melting, grant number 1325504103) and the A*STAR Additive Manufacturing Centre (AMC) Initiative: Work Package 1 (High Temperature Materials Development for 3D Additive Manufacturing, grant number 1426800088).