Effects of Different Substrates on the Formability and Densification Behaviors of Cemented Carbide Processed by Laser Powder Bed Fusion

Abstract

Cemented carbide materials are widely applied in cutting tools, drill tools, and mold fabrication due to their superior hardness and wear resistance. Producing cemented carbide parts via the laser powder bed fusion (L-PBF) method has the advantage of fabricating complex structures with a rapid manufacturing speed; however, they were underdeveloped due to their low density and crack formation on the blocks. This work studied the effect of different substrates including 316L substrates, Ni200 substrates, and YG15 substrates on the forming quality of WC-17Co parts fabricated by L-PBF, with the aim of finding the optimal substrate for fabrication. The results revealed that the Ni200 substrates had a better wettability for the single tracks formation than other substrates, and bonding between the built block and the Ni200 substrate was firm without separation during processing with a large range of laser energy inputs. This guaranteed the fabrication of a relatively dense block with fewer cracks. Although the high laser energy input that led to fine crack formation on the blocks formed on the Ni200 substrate, it was found to be better suited to restricting cracks than other substrates.

Effect of Laser Remelting Strategy on the Forming Ability of Cemented Carbide Fabricated by Laser Powder Bed Fusion (L-PBF)

“…These high-magnification pictures helped to find the tiny cracks on the blocks. It revealed that the cracks were inevitably generated on all specimens, similar to the previous studies [ 23 , 27 ]. The formation of cracks was mainly attributed to the brittleness of the cemented carbide.…”

“…All specimens were fabricated by the L-PBF system (EOSINT M280, Munich, Germany), which has a fiber laser with a maximum power of 400 W and a spot size of 100 μm. A pure nickel substrate was used in this fabrication because our previous study had proven that the nickel substrate presented excellent adhesive bonding to the WC-17Co materials for a wide range of laser energy inputs [ 27 ]. Moreover, the substrate was pre-heated to 80 °C before the fabrication.…”

“…Therefore, to achieve rapid fabrication of the cemented carbide parts with a complex shape to satisfy the requirements of the advanced industry, researchers are attempting to employ L-PBF technology for manufacturing cemented carbide parts [ 24 , 25 ]. However, the existing research found many severe defects during the L-PBF processing of cemented carbide, such as the low relative density, cracks, and high surface roughness [ 26 , 27 ]. On the one hand, these defects were primarily induced by the low flowability and brittleness of materials [ 28 , 29 ].…”

WC Grain Growth Behavior During Selective Laser Melting of WC–Co Cemented Carbides

“…The substrate material can play an important role in SLM processing of cemented carbides. Liu et al [17] successfully made WC-17Co carbide with 96% relative density via the SLM process on Ni200 substrate, which was superior to the 316L stainless steel substrate. Li et al [18] have fabricated cemented carbides via laser melting deposition and obtained higher density and fewer cracks on the cemented carbide substrate compared with the 45# steel substrate.…”