Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Investigating effects of heat treatment processes on microstructural and mechanical properties of additively manufactured 18ni300 maraging steel
Download
index.pdf
Date
2020-9-10
Author
Aydın, İbrahim
Metadata
Show full item record
Item Usage Stats
1963
views
762
downloads
Cite This
18Ni300 maraging steel (MS300) has exceptional mechanical properties due to nanosize intermetallic precipitates in martensitic matrix. It is preferred for critical aircraft components that require high strength and toughness. Very low C-content leads to good weldability and thusit is an attractive candidate for additive manufacturing (AM) techniques. In recent years, production of maraging steel components via AM techniques instead of traditional processes has gained importance in aerospace industry due to easy production of complex geometries at one step together with reduction in production time, amount of scrap, and cost. To achieve the design requirements related to the mechanical properties and to eliminate the anisotropic material behavior, the as-built parts need optimized post-AM heat treatments. Moreover, establishing easy, rapid and reliable non-destructive measurement procedures for monitoring the variations in the microstructure and mechanical properties is a challenging issue. In this study, the effects of solution and aging treatments on the microstructure and mechanical properties of 18Ni300 maraging steel that was additively produced by the selective laser melting (SLM) method were investigated. Optical microscopy, scanning electron microscopy, x-ray diffraction, hardness test, tensile test, and ultrasound velocity measurements have been performed vi to characterize the specimens. The results show that as-built specimens consist of submicron dendritic cellular structures in the horizontal cross-section and elongated acicular structures in the vertical cross-section. Excess number of dislocations in the lath type bcc-martensite provides favorable nucleation sites for precipitates. After aging treatment, the hardness increased from 370 HV to nearly 610 HV due to precipitation of Ni3Ti, Ni3Mo and Fe2Mo. Meanwhile, the ultimate tensile strength increased from 1200 MPa up to 2100 MPa with a corresponding 60 percent reduction in the % elongation. There are correlations between ultrasonic wave velocity and some mechanical properties, such as elastic modulus and hardness. This makes the sound velocity measurement a potential tool for non-destructive characterization of the microstructure and mechanical properties and monitoring of their variations in the additively manufactured and heat-treated maraging steel components.
Subject Keywords
Maraging steel
,
Additive manufacturing
,
Selective laser melting
,
Heat treatment
,
Non-destructive material characterization
,
Sound velocity
URI
https://hdl.handle.net/11511/69042
Collections
Graduate School of Natural and Applied Sciences, Thesis
Suggestions
OpenMETU
Core
Investigation of structural, electronic, magnetic and lattice dynamical properties for XCoBi (X: Ti, Zr, Hf) Half-Heusler compounds
Surucu, Gokhan; IŞIK, MEHMET; CANDAN, ABDULLAH; Wang, Xiaotian; Güllü, Hasan Hüseyin (Elsevier BV, 2020-06-15)
Structural, electronic, magnetic, mechanical and lattice dynamical properties of XCoBi (X: Ti, Zr, Hf) Half-Heusler compounds have been investigated according to density functional theory and generalized gradient approximation. Among alpha, beta and gamma structural phases, gamma-phase structure has been found as the most stability characteristics depending on the calculated formation enthalpies, energy-volume dependencies and Cauchy pressures. Energy-volume plots of possible magnetic orders of gamma-phase ...
Comparison of Natural Halloysite With Synthetic Carbon Nanotubes in Poly(lactic acid) Based Composites
Erpek, Canan Esma Yeniova; ÖZKOÇ, GÜRALP; Yılmazer, Ülkü (Wiley, 2017-11-01)
The objective of this study is to compare the mechanical properties, structure and degradability of the nanocomposites prepared with tubular nanofillers, halloysite (HNT) and carbon nanotube (CNT) in poly(lactic acid) (PLA), and thermoplastic polyurethane (TPU) toughened PLA (T-PLA) matrices. In the PLA matrix, CNT increased, whereas HNT decreased the tensile strength with increasing filler content. Also, the elongation at break and impact strength decreased with increasing CNT content, but these properties...
Theoretical prediction of bulk glass forming ability (BGFA) of Ti-Cu based multicomponent alloys
SUER, Sila; Mehrabov, Amdulla; Akdeniz, Mahmut Vedat (Elsevier BV, 2009-03-01)
The bulk glass forming ability (BGFA) of Ti-Cu based multicomponent alloys has been evaluated via theoretical modeling and computer simulation studies based on a combination of electronic theory of alloys in the pseudopotential approximation and the statistical thermodynamical theory of liquid alloys The. magnitude of atomic ordering energies, calculated by means of the electronic theory of alloys in the pseudopotential approximation, was subsequently used for calculation of the key thermodynamic parameters...
Investigation of microstructure inhomogeneity in SiCp-reinforced aluminum matrix composites
Gacsi, Zoltan; Gür, Cemil Hakan; Makszimus, Andrea; Pieczonka, Tadeusz (2007-01-01)
The type, volume fraction, size, shape and arrangement of embedded particles influence the mechanical properties of the particle reinforced metal matrix composites. This presents the investigation of the SiC particle and porosity distributions in various aluminum matrix composites produced by cold- and hot-pressing. The inicrostructures were characterized by optical microscopy and stereological parameters. SiC and porosity volume fractions, and the anisotropy distribution function were measured to establish...
Investigating the Effects of Repair Welding on Microstructure, Mechanical Properties, and Corrosion Behavior of IN-939 Superalloy
Mashhuriazar, Amirhossein; Badihehaghdam, Mohammadhassan; Gür, Cemil Hakan; Ertürk, Murat Tolga; Batıgün, Caner; Tirkeş, Süha; Sajuri, Zainuddin; Omidvar, Hamid (2022-11-01)
This study aimed to investigate the effects of tungsten inert gas (TIG) repair welding on microstructure, mechanical properties, and corrosion resistance of Inconel 939. After welding with Inconel 625 filler under argon atmosphere, the microstructure, hardness, tensile strength, and corrosion resistance of the specimens were analyzed. The results showed that the hardness value and corrosion resistance decreased in the heat-affected zone and particularly in the fusion zone. These changes were attributed to a...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
İ. Aydın, “Investigating effects of heat treatment processes on microstructural and mechanical properties of additively manufactured 18ni300 maraging steel,” M.S. - Master of Science, Middle East Technical University, 2020.