In-situ VN reinforced powder metallurgy M30 steels prepared from water atomized powers via pressureless sintering

ABSTRACT

In this paper, in-situ VN reinforced powder metallurgy high-speed steel was fabricated from water atomised powder via pressureless sintering. During sintering, N would replace C to react with V, resulting in the formation of in-situ VN phase. According to the first-principles calculations, the formation energy of VN was – 9.45 eV while that of VC was – 9.08 eV. The relative density of as-sintered samples reached up to 99%. Homogeneous microstructure and fine reinforced phases were obtained. Ultrafine VN phase (0.5 μm) was uniformly distributed in the matrix. As a result, the mechanical properties were improved. The optimal mechanical performance was obtained in the sample with 1.0 wt.% C addition. The hardness, bend strength and impact energy were 65 HRC, 3011 MPa and 18–22 J, respectively. Besides, the sintering window significantly increased from ∼10 to 30∼50°C.

KEYWORDS:

• High-speed steel
• pressureless sintering
• VN
• microstructure
• mechanical performance

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Haixia Sun is Ph.D. candidate in Engineering at the University of Science and Technology Beijing. She is engaged in the researches on powder metallurgy iron-based materials.

Fang Yang is a Ph.D. in Engineering and works as a lecturer at the University of Science and Technology Beijing. Her research interests include powder metallurgy titanium and titanium alloys, aluminum and aluminum alloys, copper and copper alloys, 3D printing, iron-based alloys, self-propagating high temperature synthesis (SHS), and magnetic materials.

Qian Qin is Ph.D. candidate in Engineering at the University of Science and Technology Beijing. He is engaged in the researches on powder metallurgy iron-based materials.

Biao Zhang is a master in Engineering graduated from the University of Science and Technology Beijing. He is engaged in the researches on powder metallurgy iron-based materials.

Alex A. Volinsky is an Associate Professor at the University of South Florida, USA. He is an expert in thin films processing, mechanical properties and characterization, adhesion and fracture of thin films, nanoindentation, pattern formation, irradiated materials properties and X-Ray diffraction.

Zhimeng Guo is a Professor and Ph.D. supervisor working at the University of Science and Technology Beijing. He offers courses in Powder Metallurgy. He is an expert in powder metallurgy titanium and titanium alloys, aluminum and aluminum alloys, copper and copper alloys, 3D printing, iron-based alloys, dispersion strengthened materials, radio frequency inductively coupled plasma spheroidization technology, self-propagating high temperature synthesis (SHS), advanced powder metallurgy technologies and materials.

ORCID

Alex A. Volinsky http://orcid.org/0000-0002-8520-6248

Additional information

Funding

This work was supported by the China Postdoctoral Research Foundation [No. 2018M641188] and the Fundamental Research Funds for the Central Universities [No. FRF-TP-18-025A1].