A comprehensive review of nanostructured materials by ultrasonic nanocrystal surface modification technique

Abstract

Nanostructured materials (NMs) possess outstanding properties than conventional coarse-grained (CG) materials. Hence designing potentially cost-efficient and environmentally products made of NMs with better are on high demand. This paper gives a comprehensive review of the most recent progress in production, characterisation and fundamental understanding of NMs produced by ultrasonic nanocrystal surface modification (UNSM) technique. In this review, we demonstrate a detailed description of the literature on the subject as well as highlight challenges for the production of NMs. Recently, this technique has also been applied to thermal spray ceramic coatings and the newly obtained experimental results are also discussed.

Review of Residual Stress Impingement Methods to Mitigate Environmental Fracture Susceptibility

“…The impact of shot on the alloy surface leaves dimples that form a gradient of compressive residual stress that commonly reaches 0.25-0.50 mm in depth [14,15]. The ultrasonic nanocrystal surface modification (UNSM) process uses a tungsten carbide-tipped applicator that is pressed down onto the alloy surface with a specific load and vertically vibrates at an ultrasonic frequency while moving systematically around the alloy surface [16]. The UNSM process is schematically illustrated in Figure 1B.…”

“…The UNSM process is schematically illustrated in Figure 1B. This treatment is computer-directed; therefore, a uniform surface coverage is achieved that results in a low hardness increase and a low surface roughness increase in a variety of alloys [16]. UNSM commonly forms a nanocrystalline grain structure below the alloy surface, and the CRS depth tends to be similar to that seen with SP [16].…”

“…This treatment is computer-directed; therefore, a uniform surface coverage is achieved that results in a low hardness increase and a low surface roughness increase in a variety of alloys [16]. UNSM commonly forms a nanocrystalline grain structure below the alloy surface, and the CRS depth tends to be similar to that seen with SP [16]. Laser shock peening utilizes laser energy bombardment to impact a surface water layer and create plasma pulses through an underlying material, which drives in the CRS [6,15].…”

Fretting wear behavior of Inconel 718 alloy manufactured by DED and treated by UNSM

“…UNSM induces surface severe plastic deformation (SSPD) along with a gradient grain layer in the microstructure, which modifies the mechanical properties and surface roughness of material, thereby lifting its wear resistance 33 . The grain size and its distribution are the primary manifestations of microstructure, and UNSM is capable of refining coarse grains into nano-grains (as small as 50 nm) with a gradient shift in its distribution 34 . The grain size is finer closer to the surface, and it gradually increases in the direction of depth.…”

“…There are quite a lot experimental results showing that UNSM technology plays an effective role in optimizing mechanical and tribological properties 35 – 37 . The ability to optimize surface quality by adjusting well-defined process parameters such as normal load, amplitude, frequency, and feed rate is one of the greatest benefits of UNSM technology 34 . The average incremental values for roughness and hardness brought by UNSM for a given set of process parameters are 58% and 27%, respectively 38 .…”