Effects of Printing Layer Orientation on the High-Frequency Bending-Fatigue Life and Tensile Strength of Additively Manufactured 17-4 PH Stainless Steel

Abstract

In this paper, small blocks of 17-4 PH stainless steel were manufactured via extrusion-based bound powder extrusion (BPE)/atomic diffusion additive manufacturing (ADAM) technology in two different orientations. Ultrasonic bending-fatigue and uniaxial tensile tests were carried out on the test specimens prepared from the AM blocks. Specifically, a recently-introduced small-size specimen design is employed to carry out time-efficient fatigue tests. Based on the results of the testing, the stress–life (S-N) curves were created in the very high-cycle fatigue (VHCF) regime. The effects of the printing orientation on the fatigue life and tensile strength were discussed, supported by fractography taken from the specimens’ fracture surfaces. The findings of the tensile test and the fatigue test revealed that vertically-oriented test specimens had lower ductility and a shorter fatigue life than their horizontally-oriented counterparts. The resulting S-N curves were also compared against existing data in the open literature. It is concluded that the large-sized pores (which originated from the extrusion process) along the track boundaries strongly affect the fatigue life and elongation of the AM parts.

Dimensional Accuracy and Mechanical Characterization of Inconel 625 Components in Atomic Diffusion Additive Manufacturing

“…In current research, studies investigating Atomic Diffusion Additive Manufacturing (ADAM), an MEAM process patented by Markforged Inc. (Boston, MA, USA), are predominately on stainless steel 17-4 PH [6][7][8][9][10][11][12][13][14][15][16][17], mostly with a focus on mechanical properties. Besides 17-4 PH, few studies investigate copper filaments [18][19][20], while research on other materials such as coldwork tool steel D2 [21] and Inconel 625 [22] is very scarce.…”

A Review on Vibration Characteristics of Additively Manufactured Metal Alloys

“…[74,75] The printing orientation can influence the vibration characteristics of a material in AM. [22,23,76] For instance, Lesage et al analyzed the vibrational response of AlSi10Mg samples produced using conventional and AM methods. [21] The AM samples were printed in horizontal (flat), vertical (upright), and rotated orientations, with the build angle ranging from 0°to 90°.…”

“…Laser‐based techniques comprise numerous process attributes such as hatch spacing, laser power, scan speed, spot size, [ 15–19 ] deposition orientation, [ 15,20–23 ] or geometry. [ 24 ] These attributes, along with the scanning strategy and component shape, affect thermal history and determine the mechanical properties of the as‐built parts.…”

Rapid evaluation of fatigue limit using energy dissipation

“…Nevertheless, predicting the fatigue behavior of different materials still remains to be a challenging task and has motivated researchers to develop efficient, cost-effective methods for predicting the material's behavior under cyclic loading. [12][13][14][15][16] Among different methods, thermography has emerged as an ideal technique to evaluate energy dissipation during cyclic loading. It is worthwhile to mention that the application of thermography in predicting the fatigue limit has been verified in comparison with statistical approaches.…”