Effect of holding time on the growth morphology of in-situ TiB2 particles

2021 ◽  
pp. 102953
Author(s):  
Pian Xu ◽  
Gang Lu ◽  
Lei Zhang ◽  
Shitong Zhou ◽  
Yuping Yan ◽  
...  
2021 ◽  
Vol 63 (7) ◽  
pp. 630-638
Author(s):  
Mustafa Kaptanoglu ◽  
Mehmet Eroglu

Abstract In the study for this contribution, production of in situ synthesized TiB2 particles in iron-based composite coatings using four different submerged arc welding powders (fluxes) containing increasing amounts of ferrotitanium and ferroboron with S1 welding wire, were targeted. For this purpose, coating deposition was carried out to improve the hardness and wear properties of the AISI 1020 steel surfaces using hybrid submerged arc welding. In hybrid submerged arc welding, the welding pool is protected by both welding powders and an argon gas atmosphere. To examine the composite coatings, visual, chemical, microstructural analyses and hardness and wear tests were carried out. With the use of increasing amounts of ferrotitanium and ferroboron in the welding powders, it was observed that the microstructure of the coatings changed in terms of TiB2 particle geometries such as rectangular and hexagonal; volume fractions of TiB2 particles in the coating microstructures increased; hardness values of coatings were enhanced from 34 HRC to 41 HRC; the wear resistance of the coatings improved, and worn surface images of the coatings caused by the counter body changed from continuous with deep scratches to discontinuous with fine scratches and crater cavities.


2008 ◽  
Vol 489 (1-2) ◽  
pp. 220-226 ◽  
Author(s):  
A. Mandal ◽  
M. Chakraborty ◽  
B.S. Murty

2018 ◽  
Vol 128 ◽  
pp. 130-139 ◽  
Author(s):  
Peng Xiao ◽  
Yimin Gao ◽  
Feixing Xu ◽  
Cuicui Yang ◽  
Yefei Li ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5319
Author(s):  
Haofei Zhu ◽  
Jun Liu ◽  
Yi Wu ◽  
Qing Zhang ◽  
Qiwei Shi ◽  
...  

Isothermal compression tests of in-situ TiB2/7050Al composites fabricated by powder metallurgy were performed at 300–460 °C with the strain rate varying from 0.001 s−1 to 1 s−1. The Arrhenius constitutive equation and hot processing map of composites were established, presenting excellent hot workability with low activation energies and broad processing windows. Dramatic discontinuous/continuous dynamic recrystallization (DDRX/CDRX) and grain boundary sliding (GBS) take place in composites during deformation, depending on the Zener-Hollomon parameter (Z) values. It is found that initially uniform TiB2 particles and fine grain structures are beneficial to the DDRX, which is the major softening mechanism in composites at high Z values. With the Z value decreasing, dynamic recovery and CDRX around particles are enhanced, preventing the occurrence of DDRX. In addition, fine grain structures in composites are stable at elevated temperature thanks to the pinning of dense nanoparticles, which triggers the occurrence of GBS and ensures good workability at low Z values.


2002 ◽  
Vol 11 (2) ◽  
pp. 096369350201100
Author(s):  
E. S. Thian ◽  
N. H. Loh ◽  
K. A. Khor ◽  
S. B. Tor

Prior to the actual sintering process, a dilatometry study is performed to provide basic information and guidelines. This paper studies the effects of three sintering factors: sintering temperature, heating rate and holding time, on the densification rate of Ti-6Al-4V/HA composite parts. According to the in-situ test results, suitable values for the sintering factors can then be established.


2011 ◽  
Vol 675-677 ◽  
pp. 473-476 ◽  
Author(s):  
N.N. Wu ◽  
C.F. Fang ◽  
Yun Bai ◽  
L.G. Meng ◽  
Hai Hao ◽  
...  

The TiB2/AZ31 magnesium matrix composite was fabricated via self-propagating hightemperature synthesis (SHS) and then hot extruded. The influence of hot extrusion on the microstructure and property of TiB2/AZ31 composites was investigated. The results show that hot extrusion and synthesized TiB2 particles could refine the grain size obviously. The synthesized TiB2 particles are micro- and nano-sized, dispersing homogenously in the matrix. The interface between the matrix and the particles are good bonding. Meanwhile, slip and twinning are the main deformation modes during the hot extrusion. The fracture surface of hot-extruded TiB2/AZ31 magnesium matrix composite has more dimples than the as-cast AZ31 magnesium alloy. The improvement of microstructure seems to be beneficial for the fracture ductility of TiB2/AZ31 magnesium matrix composite.


2012 ◽  
Vol 512-515 ◽  
pp. 639-642 ◽  
Author(s):  
Xiao Qin Guo ◽  
Jing Bo Chen ◽  
Xin Fang Zhang ◽  
Yong Kai Wang ◽  
Rui Zhang

Cu-TiB2 composite coatings were in-situ synthesized on the copper substrate by using a Nd: YAG laser. The microstructure of the coating and the bonding interface between the laser cladding layer and the substrate were studied by X-ray and SEM. The microhardness and the wear resisting property were tested. The results show that the TiB2 particles were well-proportioned and spherical existing in the coating layer, the bonding interface between the layer and substrate was metallurgical bonding. The microhardness reaches HV450 and the wear resistance is about 10 times as much as that of Cu substate.


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