Additive Manufacturing Fatigue and Fracture: Effects of Surface Roughness, Residual Stress, and Environment: Poster Session
Sponsored by: TMS Structural Materials Division, TMS: Additive Manufacturing Committee, TMS: Mechanical Behavior of Materials Committee
Program Organizers: Nik Hrabe, National Institute of Standards and Technology; John Lewandowski, Case Western Reserve University; Nima Shamsaei, Auburn University; Steve Daniewicz, University of Alabama; Mohsen Seifi, ASTM International/Case Western Reserve University
Monday 5:30 PM
March 20, 2023
Room: Exhibit Hall G
Location: SDCC
Session Chair: Nik Hrabe, National Institute of Standards and Technology
Evolution of Fatigue Behavior of Low Carbon Multiphase Steel Developed through Quench and Partitioning Method: Sk Md Arif1; 1National Institute of Technology Durgapur
In this present investigation, quenching and partitioning method was applied to deformed low carbon multiphase steels. The Effect of partitioning temperature after quenching below and above Ms temperature on the microstructure and mechanical properties are investigated. The resulting multiphase microstructures are investigated by using optical microscopy, Scanning Electron microscopy and X-ray diffraction techniques. The mechanical properties are evaluated. The microstructure consists of martensite/bainite, temper- martensite and retained austenite. The tensile strength significantly increases than deformed steels but ductility decreases. The fatigue strength is increase in 300C and 350C. The quenching below Ms temperature and holding at 300C shows a good strength and ductility combination with Fatigue strength.
A-7: Investigating the Effect of Heat Treatment on the Process-Structure-Property Relationship of AlSi10Mg Produced through Selective Laser Melting: Youssef Salib1; Hatem Zurob1; David Wilkinson1; 1McMaster University
Additive Manufacturing (AM) has the ability to produce parts of high strength due to the rapid cooling rates associated with the process. As a result, the ductility will naturally suffer as a consequence. The material of interest is a popular aluminum alloy (AlSi10Mg) that contains 10% silicon and is widely used in the space industry for its good mechanical properties and light weight. This alloy will be studied to observe the impact of applying heat treatments on the damage evolution and mechanical properties of AlSi10Mg produced through additive manufacturing. Techniques such as in-situ tensile testing via x-ray computed tomography and in-situ tensile testing via scanning electron microscopy (SEM) coupled with micro-digital image correlation (μ-DIC) will help connect microstructural features to areas of high strain localization and void growth, such that a process-structure-property relationship can be established.
Microstructural Evolution and Mechanical Behaviour of L-PBF Processed 17-4 PH Stainless Steel: Bijit Kalita1; Jayaganthan R.1; 1Indian Institute of Technology Madras
Laser Powder Bed Fusion (L-PBF) is the most prominent additive manufacturing method that provides higher accuracy and powder proficiency in comparison to other methods. Additively manufactured 17-4 PH stainless steel exhibited a dendritic solidification microstructure in the as-built condition. This study provides an insight into the comparison of the tensile and fracture toughness properties between 17-4 PH SS samples processed by L-PBF 17-4 PH samples. The tests were conducted according to the international standard ASTM E8, E399, E647 and the effect of different heat treatments were also studied. FCG tests were conducted under force-controlled mode at room temperature. Microstructure characterization and fractography analysis were carried out to elaborate the crack growth mechanism with respect to different heat treatment conditions and crack growth directions. The L-PBF processed sample displayed significantly higher ductility and ultimate tensile strength (UTS) with respect to wrought samples.
A-8: Parameterizing Surface Defects and Internal Porosity to Predict Fracture Location in As-built AM Tensile Specimens Using a Modified Void Descriptor Function: Elliott Marsden1; Dillon Watring2; John Erickson3; Laura Ziegler1; Andrew Chuang4; Ashley Spear1; 1University of Utah; 2United States Naval Research Laboratory; 3Sandia National Laboratories; 4Argonne National Laboratory
Predicting fracture location (FL) in as-built AM metal components is difficult given the complex interaction between surface defects and internal voids. Previously, a Void Descriptor Function (VDF) was derived to provide an analytical approach to estimate FL in a uniaxially loaded specimen given its internal pore network (PN). Although the VDF has been shown to perform well in predicting FL in both simulated and experimental specimens, its prediction performance is expected to decrease in cases for which surface roughness influences fracture behavior. This work aims to extend the VDF to account for surface defects while retaining current mechanical-property correlation and predictive capabilities. A screening strategy is proposed to locate and parameterize critical surface defects in X-ray computed tomography image stacks. Proper surface-pore characterization and parametric representation in the VDF could potentially lead to efficient, accurate predictions of fracture in as-built components where both surface roughness and internal PNs are critical.