Investigation of Laser-Based Surface Coating/Alloying of Steel Substrates Using Hard Carbides
Abstract
The objective of this project is to investigate the coating/alloying of steel surfaces with a hard carbide to improve hardness and wear resistance, with application to metal forming dies. A laser-based additive manufacturing approach, viz., a derivative of selective laser melting (SLM) was used to bond WC-17Co powder on stainless steel and H13 tool steel substrates. An experimental design was created to investigate effects of volumetric energy density (VED) based process parameters on the integrity and properties of the resulting surfaces via microscopy, interferometry, spectroscopy and hardness measurements. Results show up to a 400%+ increase in the surface hardness. With an increasing VED, cracking, spatter, and %W on the surface reduced, while W was detected deeper into the surface, suggesting that an alloying mechanism was gaining dominance. These were further correlated with the differences due to substrates (stainless vs. H13 tool steel) and the original surface characteristics (lapped vs. machined), thus enabling this approach for the coating/alloying of metal forming dies.
Citation
Hurst, Michael T (2020). Investigation of Laser-Based Surface Coating/Alloying of Steel Substrates Using Hard Carbides. Master's thesis, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /193023.