scholarly journals Mechanical Properties of Tool Steels with High Wear Resistance via Directed Energy Deposition

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 282 ◽  
Author(s):  
Gyeong Yun Baek ◽  
Gwang Yong Shin ◽  
Ki Yong Lee ◽  
Do Sik Shim
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Resistance ◽  
Energy Deposition ◽  
High Wear Resistance ◽  
Matrix Microstructure ◽  
Microstructure Observation ◽  
Directed Energy Deposition ◽  
Directed Energy ◽  
Post Deposition

This study focused on the mechanical and metallurgical characteristics of high-wear-resistance steel (HWS) deposited using directed energy deposition (DED) for metal substrate hardfacing or repairing. As post-deposition heat treatment changes the metallurgical characteristics of deposits, the effect of post-deposition heat treatment on the mechanical properties was investigated via microstructure observation and by conducting hardness, wear, and impact tests. The obtained micro-images showed that the deposited HWS layers exhibit cellular and columnar dendrites, and the microstructure of heat-treated HWS (HT-HWS) transformed its phase during quenching and tempering. The hardness and wear resistance of the HT-HWS deposits were higher than those of the HWS deposited specimen, whereas the latter exhibited a higher fracture toughness. The matrix microstructure and carbide characteristics, which are characterized by the chemical composition of the materials, significantly influenced the mechanical properties.

scholarly journals Fabrication of a TiC-Ti Matrix Composite Coating Using Ultrasonic Vibration-Assisted Laser Directed Energy Deposition: The Effects of Ultrasonic Vibration and TiC Content

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 693
Author(s):  
Yunze Li ◽  
Dongzhe Zhang ◽  
Hui Wang ◽  
Weilong Cong
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Ultrasonic Vibration ◽  
Matrix Composite ◽  
Energy Deposition ◽  
Bonding Quality ◽  
Manufacturing Defects ◽  
Directed Energy Deposition ◽  
Fabrication Defects ◽  
Directed Energy

Titanium and its alloys exhibit superior properties of high corrosion resistance, an excellent strength to weight ratio and outstanding stiffness among other things. However, their relatively low hardness and wear resistance limit their service life in high-performance applications of structure parts, gears and bearings, for example. The fabrication of a ceramic reinforced titanium matrix composite (TMC) coating could be one of the solutions to enhance the microhardness and wear resistance. Titanium carbide (TiC) is a preferable candidate due to the advantages of self-lubrication, low cost and a similar density and thermal expansion coefficient with titanium. The fabrication of TiC-TMC coatings onto titanium using a laser directed energy deposition (LDED) process has been conducted. The problems of TiC aggregation, low bonding quality and the generation of fabrication defects still exist. Considering ultrasonic vibration could generate acoustic steaming and transient cavitation actions in melted materials, which could homogenize the distribution of reinforcement materials and promote the dissolution of TiC into liquid titanium. In this study, for the first time, we investigate the ultrasonic vibration-assisted LDED of TiC-TMC coatings. The effects of ultrasonic vibration and reinforcement content on the phase compositions, reinforcement aggregation, bonding quality, fabrication defects and mechanical properties (including microhardness and wear resistance) of LDED deposited TiC-TMC coatings have been investigated. With the assistance of ultrasonic vibration, the aggregation of TiC was reduced, the porosity was decreased, the defects in the bonding interface were reduced and the mechanical properties including microhardness and wear resistance were increased. However, the excessive TiC content could significantly increase the TiC aggregation and manufacturing defects, resulting in the reduction of the mechanical properties.

scholarly journals Microstructures and Mechanical Properties of Deposited Fe-8Cr-3V-2Mo-2W on SCM420 Substrate Using Directed Energy Deposition and Effect of Post- Heat Treatment

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1231
Author(s):  
Ye Eun Jeong ◽  
Jun Yeop Lee ◽  
Eun Kyung Lee ◽  
Do Sik Shim
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Fracture Toughness ◽  
Tensile Strength ◽  
Wear Resistance ◽  
Energy Deposition ◽  
Surface Hardness ◽  
Steel Powder ◽  
Post Heat Treatment ◽  
Directed Energy

In this study, the Fe-8Cr-3V-2Mo-2W tool steel powder was deposited on the SCM420 substrate through the directed energy deposition (DED) process. This study focuses on the mechanical properties of the deposited Fe-8Cr-3V-2Mo-2W and the effect of heat treatment on it. The changes in the microstructural characteristics of the deposited region due to heat treatment after deposition were observed. The influence of heat treatment on the mechanical properties was then analyzed accordingly and hence, the hardness, wear, impact and tensile tests were conducted on the deposited material. These properties were compared with those of the commercial tool steel powder M2-deposited material and the carburized specimen. In the deposited Fe-8Cr-3V-2Mo-2W layer, an increased martensite phase fraction was obtained through post-heat treatment and the amount of precipitated carbides was also increased. This increased the hardness from 48 to 62 HRc after heat treatment and the wear resistance was significantly improved as well. The amount of impact energy absorbed decreased from 11 J before heat treatment to 6 J after heat treatment, but the tensile strength significantly increased from 607 to 922 MPa. When compared with the M2-deposited surface, the Fe-8Cr-3V-2Mo-2W deposits had 3% lower surface hardness and 76% lower fracture toughness but exhibited 56% higher tensile strength. When compared with the carburized SCM420, the Fe-8Cr-3V-2Mo-2W deposits exhibited 3% higher surface hardness and wear resistance, 90% lower fracture toughness and 5% higher tensile strength. This study shows that surface hardening through DED can exhibit similar or superior mechanical properties when compared to carburizing.

Towards controlling intrinsic heat treatment of maraging steel during laser directed energy deposition

2021 ◽  
Vol 201 ◽  
pp. 113973
Author(s):  
Sasan Amirabdollahian ◽  
Faraz Deirmina ◽  
Luke Harris ◽  
Raveendra Siriki ◽  
Massimo Pellizzari ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Maraging Steel ◽  
Energy Deposition ◽  
Directed Energy Deposition ◽  
Directed Energy
Sign in / Sign up

Export Citation Format

Share Document