Fabrication of a TiC-Ti Matrix Composite Coating Using Ultrasonic Vibration-Assisted Laser Directed Energy Deposition: The Effects of Ultrasonic Vibration and TiC Content

Abstract

Titanium and its alloys exhibit superior properties of high corrosion resistance, an excellent strength to weight ratio and outstanding stiffness among other things. However, their relatively low hardness and wear resistance limit their service life in high-performance applications of structure parts, gears and bearings, for example. The fabrication of a ceramic reinforced titanium matrix composite (TMC) coating could be one of the solutions to enhance the microhardness and wear resistance. Titanium carbide (TiC) is a preferable candidate due to the advantages of self-lubrication, low cost and a similar density and thermal expansion coefficient with titanium. The fabrication of TiC-TMC coatings onto titanium using a laser directed energy deposition (LDED) process has been conducted. The problems of TiC aggregation, low bonding quality and the generation of fabrication defects still exist. Considering ultrasonic vibration could generate acoustic steaming and transient cavitation actions in melted materials, which could homogenize the distribution of reinforcement materials and promote the dissolution of TiC into liquid titanium. In this study, for the first time, we investigate the ultrasonic vibration-assisted LDED of TiC-TMC coatings. The effects of ultrasonic vibration and reinforcement content on the phase compositions, reinforcement aggregation, bonding quality, fabrication defects and mechanical properties (including microhardness and wear resistance) of LDED deposited TiC-TMC coatings have been investigated. With the assistance of ultrasonic vibration, the aggregation of TiC was reduced, the porosity was decreased, the defects in the bonding interface were reduced and the mechanical properties including microhardness and wear resistance were increased. However, the excessive TiC content could significantly increase the TiC aggregation and manufacturing defects, resulting in the reduction of the mechanical properties.

Additive manufacturing of refractory metals and carbides for extreme environments: an overview

“…Ultrasonic vibration in AM has been used to improve the printability of refractory materials and other material systems. [135][136][137][138][139][140][141][142][143][144][145][146][147][148] Figure 9(a) shows a schematic of an ultrasonic vibration setup integrated with laser-based AM process. The introduction of high-intensity ultrasonic vibrations for microstructure modification has been studied in the literature to understand the advantages of ultrasonic cavitation, dendrite fragmentation, and acoustic streaming.…”

A study on thermal behaviour of thermal barrier coating: investigation of particle size, YSZ/polysilazane, time and temperature curing effect

“…The smaller the particle size, the easier it is to form porous composites due to the high spatial arrangement exibility required to produce a pore. 35 In addition, variations in composition showed signicant morphological differences, with specimens with a composition of 70/30 producing the most pores compared to other variations due to the existence of polysilazane that does not cover the entire surface of the CRFP, leaving still pores on the composite layer. Meanwhile, the 50/50 composition tends to be a denser composite due to the abundance of polysilazane content, which can cause crack formation.…”

In situ synthesis and characterization of ceramic reinforced Inconel 718 coatings using B4C-Inconel 718 powders by laser-directed energy deposition

“…In the laser DED process, the cooling rate was extremely high. Entrapped gas bubbles were di cult to be e ciently expelled before the molten pool solidi ed [22]. Compared with Inconel 718 coatings, the number of micropores in B 4 C-Inconel 718 coatings was much smaller than that in Inconel 718 coatings.…”