Development in PTA Surface Modifications – A Review

Abstract

<jats:title>Abstract</jats:title><jats:p>Surface modification is one of the most intensively studied issue of technology, which is related to the almost all branches of industry. Since more than 100 years the huge number of methods has been developed and are still in growth. On this field the plasma transferred arc (PTA) hardfacing and surfacing is one of the most frequently used group of the method. The development of this method is going in three ways: (i) modification of the classic technique and the equipment, (ii) development in new materials, especially with the nanometric size and (iii) replacement dangerous materials (e.g. high cobalt alloys). In the current article the state of the art as well as the development directions of the plasma hardfacing issues are described.</jats:p>

Factors Influencing Cavitation Erosion of NiCrSiB Hardfacings Deposited by Oxy-Acetylene Powder Welding on Grey Cast Iron

“…Worn ferrous machine components, depending on the cost analysis are replaced by new parts or regenerated. Thus the broad range of surface engineering techniques likewise induction hardening [15], thermal spraying [16,17], conventional overlay welding and cladding [18,19], wet (underwater) welding [20,21] or surface alloying [22,23] are utilised. Literature reports that the most typical materials for regenerating or prolonging thw operation time of cast iron machine parts are polymers [24,25], metal alloys [26,27] or different composites [28,29].…”

A comprehensive review on recent developments in materials and technological parameters for plasma transferred arc hardfacing process

“…PTA permits precise control of important process parameters, that is amperage, voltage, powder feed rates, gas flow rates, morphology of powder particles as well as its size distribution and heat input, for high degree of consistency in the overlay. 82–86 Arc current, plasma gas flow, shielding gas flow, welding speed, and nozzle diameter are the significant parameters affecting the keyhole PTA process. 43 Controlled heat input enables greater control over weld dilutions in most cases.…”

Properties of Flame Spraying Coatings Reinforced with Particles of Carbon Nanotubes

“…The carbon nanotubes were of shorter length as during the deposition process they fractured because of impact and shear between the Al-Si particles and the aluminum matrix. A. K. Keshri and the others [16] compared the impact on carbon nanotubes (CNTs) of various heat sources used during thermal spray processesplasma spraying (PS), high-velocity oxy fuel spraying (HVOF), cold spraying (CS) and plasma spraying of liquid precursor (PSLP) [40]. Carbon nanotubes (CNTs) have been successfully preserved as reinforcements in composite metal and ceramic coatings in all thermal spray processes, except for PSLP.…”