Microstructure and Sliding Wear Behaviour of In-Situ TiC-Reinforced Composite Surface Layers Fabricated on Ductile Cast Iron by Laser Alloying

Abstract

TiC-reinforced composite surface layers (TRLs) on a ductile cast iron EN-GJS-700-2 grade (DCI) substrate were synthesized using a diode laser surface alloying with a direct injection of titanium powder into the molten pool. The experimental results were compared with thermodynamic calculations. The TRLs having a uniform distribution of the TiC particles and their fraction up to 15.4 vol % were achieved. With increasing titanium concentration in the molten pool, fractions of TiC and retained austenite increase and the shape of TiC particles changes from cubic to dendritic form. At the same time, the cementite fraction decreases, lowering the overall hardness of the TRL. A good agreement between experimental and calculated results was achieved. Comparative dry sliding wear tests between the as-received DCI, the TRLs and also laser surface melted layers (SMLs) have been performed following the ASTM G 99 standard test method under contact pressures of 2.12 and 4.25 MPa. For both the as-received DCI and the SMLs, the wear rates increased with increasing contact pressure. The TRLs exhibited a significantly higher wear resistance than the others, which was found to be load independent.

Hybrid Laser Deposition of Fe-Based Metallic Powder under Cryogenic Conditions

“…This is because the laser beam offers many advantages, the most important of which are high flexibility, high power densities, localized or selective heating, high processing speed, and low heat input [9][10][11][12][13][14][15]. One of the areas of laser beam application that is currently being widely developed is shaping the properties of surface layers and manufacturing of coatings for enhanced wear characteristics (e.g., corrosion, tribological, abrasive, thermal, and mechanical fatigue or impact load) [16][17][18][19][20][21].…”

Abrasion Resistance of S235, S355, C45, AISI 304 and Hardox 500 Steels with Usage of Garnet, Corundum and Carborundum Abrasives

“…Moreover, recently the wear resistance of steel and other iron-based alloys has been enhanced by means of various advanced treatments. For example, ion implantation was used for increasing the wear resistance of Hardox and Raex steel [30], cast iron surface laser alloying with Ti powder was studied in [31], shoot peening surface modification [32] or surface engineering treatments such as fabrication of chromosiliconized layer on C45 steel [12]. Additionally, the thermal spray technology is applied to deposit the wear resistant coatings e.g.…”

“…However, the selection for wear application of commercial steels seems to be still an up-to-date and unsolved problem. Even though the white cast irons abrasion resistance is unquestionable [31,[35][36][37], the selection of resistant to abrasion steel remains a tricky task, especially taking into account the cost-effectiveness factor and outstanding structural properties of the steel.…”

Influence of Solidification Conditions on the Microstructure of Laser-Surface-Melted Ductile Cast Iron

“…Additionally, compared with other laser surface modification methods, such as laser surface alloying and cladding processes, LSM is a relatively simple process since it does not change the chemical composition of the processed surface layer [8][9][10]. However, the inability to change the chemical composition of the melt also significantly limits the ability to change the microstructure and mechanical properties of the processed surface layer [11]. During LSM, the mechanical properties of the processed layers can typically only be modified by controlling the solidification conditions in the molten pool [12,13].…”