Acta Metallurgica Sinica (English Letters) ›› 2019, Vol. 32 ›› Issue (1): 127-135.DOI: 10.1007/s40195-018-0752-2

• Orginal Article • Previous Articles     Next Articles

Cracking Behavior in Additively Manufactured Pure Tungsten

Dian-Zheng Wang1, Kai-Lun Li1, Chen-Fan Yu1, Jing Ma1, Wei Liu1(), Zhi-Jian Shen1,2()   

  1. 1.State Key Laboratory of New Ceramic and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China
    2.Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, 106 91 Stockholm, Sweden
  • Received:2018-02-22 Revised:2018-03-27 Online:2019-01-10 Published:2019-01-18
  • Contact: Liu Wei,Shen Zhi-Jian
  • About author:

    Author brief introduction:Dao-Kui Xu Professor of IMR, CAS, and “Young Merit Scholar” of Corrosion Center in the Institute of Metal Research (IMR), Chinese Academy of Sciences (CAS). He achieved Ph.D. degree from IMR, CAS, in 2008, during which he obtained “Chinese Academy of Sciences-BHP Billiton” Scholarship award, “Shi Changxu” Scholarship award and “Zhu-LiYueHua” Excellent Doctorate Student Scholarship of Chinese Academy of Sciences. He worked as a Research Fellow in ARC Center of Excellence, Design of Light Metals, Department of Materials Engineering, Monash University, Australia (2008.10-2011.10). He published more than 60 peer-reviewed scientific papers, attended 20 invited lectures and holds seven patents. His papers were cited more than 1200 times. His research interests mainly include: (1) fatigue behavior and fracture toughness of light metals, such as Mg, Al and Ti alloys; (2) effects of alloying, heat treatment and thermomechanical processes on the microstructural evolution and mechanical improvement of light metals; (3) corrosion, stress corrosion cracking and corrosion fatigue behavior of lightweight alloys; and (4) design of new lightweight alloys with a good balance of properties in terms of mechanical property and corrosion resistance.

Abstract:

In this study, near fully dense (96.5%) pure tungsten bulks were additively manufactured and the cracking behavior was investigated. A crack network with a spacing of ~?100 μm was observed in the fabricated bulks. It was observed that the laser scanning strategy, which could tailor the microstructure, affected the crack distribution pattern in fabricated tungsten. The calculated surface temperature difference (7300 K) was much higher than the cracking criterion (800 K) of tungsten, indicating that cracking is almost inevitable in laser additive manufacturing of tungsten. It could be concluded that crack network formed because the cracks emerged in every laser molten track and then interconnected in the layer-by-layer building process.

Key words: Tungsten, Selective laser melting, Cracking, Microstructure