Potassium sodium niobate (KNN)‐based lead‐free piezoelectric ceramic coatings on steel structure by thermal spray method

Abstract

For the first time, potassium sodium niobate (KNN)‐based lead‐free piezoelectric ceramic coating with strong piezoelectric response was fabricated on stainless steel substrates by thermal spray process, after introducing NiCrAlY and yttria‐stabilized zirconia (YSZ) intermediate layers. A large effective piezoelectric coefficient (d33) of 125 pm/V was obtained with the thermal‐sprayed KNN‐based ceramic coating on the steel substrates. The mechanisms of improving the structure and enhancing the properties of the KNN‐based piezoelectric ceramic coatings by introducing the intermediate layers were analyzed. Ultrasonic transducers were designed and fabricated from the KNN‐based coatings directly formed on a steel plate structure, and the feasibility for generation and detection of ultrasonic waves for structural health monitoring using the thermal‐sprayed lead‐free piezoelectric ceramic coating was demonstrated.

Ultrasound‐Induced Wireless Energy Harvesting for Potential Retinal Electrical Stimulation Application

“…Currently, lead‐based piezoelectric materials represented by lead zirconate titanate ceramics and the related lead‐based perovskites are dominant in the piezoceramic market because of their good piezoelectric properties. Nevertheless, due to the biohazard regarding the current lead‐based piezoelectric materials and express provisions of Restriction of Hazardous Substances, the attention has been shifted to lead‐free alternatives, especially on potassium‐sodium niobate‐based piezoelectrics . In this work, a new 1‐3 piezocomposite comprising a system of high piezoelectricity lead‐free ceramic [(K 0.48 Na 0.52 )(Nb 0.95 Sb 0.05 )‐O 3 ‐(Bi 0.4 La 0.1 )(Na 0.4 Li 0.1 )ZrO 3 , abbreviated as KNNS] pillar array with parallelepipeds shape and the insulating polymer filler (EPO‐TEK 301) was designed and fabricated using a modified dice‐and‐fill technique ( Figure a) .…”

Enabling Distributed Intelligence with Ferroelectric Multifunctionalities

“…It is almost impossible to accept the toxic lead compositions in the high temperature processing in open air over large area during the thermal spray process. [247,[266][267][268] Secondly, ferroelectric materials with superior performance are to be obtained, including adequate response magnitude for directly driving energy autonomous sensor system operation and retaining the significant ferroelectric effect at low dimensions for high density computing function integration. While ferroelectrics possess the in-principle zero-energy sensing mechanism by directly converting the stimuli into electricity, the electrical output is rather low (in reference to the data as shown in Tables 1 and 2).…”

“…It is almost impossible to accept the toxic lead compositions in the high temperature processing in open air over large area during the thermal spray process. [ 247 , 266 , 267 , 268 ]…”

Structure and High Performance of Lead-Free (K0.5Na0.5)NbO3 Piezoelectric Nanofibers with Surface-Induced Crystallization at Lowered Temperature

“…23,24 To explore scalable industry applications, we explored thermal spray processing for producing KNN-based piezoelectric ceramic coatings on stainless steel substrates. 25 Compared to the research on KNN films, studies on KNN nanofibers are very limited due primarily to the difficulty in achieving high-quality fibers. In 2012, Jalalian and Grishin reported electrospun KNN fibers with an average diameter of 150 nm in randomly oriented webs and characterized them in the superparaelectric state with large separations between nanofibers.…”