Electrospark deposition of Al₂O₃–TiB₂/Ni composite-phase surface coatings on Cu–Cr–Zr alloy electrodes

Abstract

a b s t r a c tTo improve electrode life during the resistance spot welding of galvanized steel plates, an Al 2 O 3 -TiB 2 composite coating was synthesized on the surfaces of spot-welding electrodes through an electrospark deposition process. The microstructure, elemental composition, phase structure, and mechanical properties of the coating were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction analysis, and microhardness testing. It was found that extensive cracking occurred in the monolithic Al 2 O 3 -TiB 2 coating and at the coating-electrode interface. When the Al 2 O 3 -TiB 2 coating was deposited on electrodes precoated with Ni, the number of defects decreased significantly. Further, delamination did not occur, and fewer cracks were formed. The average hardness of the multilayered Al 2 O 3 -TiB 2 /Ni coating was approximately 2200 HV and higher than that of the monolithic Al 2 O 3 -TiB 2 coating (1100 HV).

Quality Surface Modification for Refractory Stainless Steel by Tungsten Deposition, Using Electro-Spark Deposition Method

“…However, in the surface layer are formed complex chemical combinations: nitrides, carbonitrides, stable carbides and hardening structures. As a result, a high strength layer may be formed only in the case of thermal and chemical interaction between the part electrode materials, [10,11,12,13,14,15,16,17].…”

Plasma-sprayed Al2O3-TiB2-SiC ternary composite coatings and its wear behaviour based on SiC content

“…The spraying conditions affect the coating characteristics, and the process parameters optimised accordingly. Luo et al [28] produced Al 2 O 3 -TiB 2 /Ni composite-phase surface coatings on Cu-Cr-Zr alloy electrodes using electro-spark deposition.…”

Composite Materials for Wear-Resistant Layers Made Using Electro-Spark Deposition

“…Moreover, the process generates a good metallurgical bond between the coating and the substrate [7]. Studies on the ESD of Al2O3-TiB2 and ZrB2-TiB2 composite coatings are discussed in works [7][8][9]. The authors also show that coating quality can be improved by depositing an Al2O3-TiB2 composite onto a Ni interlayer [8,10].…”

“…Studies on the ESD of Al2O3-TiB2 and ZrB2-TiB2 composite coatings are discussed in works [7][8][9]. The authors also show that coating quality can be improved by depositing an Al2O3-TiB2 composite onto a Ni interlayer [8,10]. The paper presents a part of the results of project APVV SK-PL-2015-0003 "Wear resistant and electrically conductive composite coatings on non-ferrous metals."…”