In situ surface modification of stainless steel with hydroxyapatite using microwave heating

Abstract

The present work involves enhancing the biocompatibility of austenitic stainless steel (SS-316L) implants by changing its surface composition and morphology through the microwave hybrid heating (MHH) technique. The polished SS-316L alloy surface layer was modified with bioactive hydroxyapatite (HAP) powder by utilizing an Industrial microwave oven operated at 2.45 GHz and 1.1 kW. The modified layer of SS-316L alloy was characterized in terms of phase analysis, microstructure investigation, porosity analysis and apatite forming ability. The microstructural investigation revealed that the presence of austenite dendrites with HAP along with some reaction induced phases like Fe 3 P, FeP, and Fe 2 P mainly in the inter-dendritic regions of the modified layer of SS-316L alloy. The microhardness of modified layer was higher than that of the unmodified layer of SS-316L alloy. The modified layer exhibited porosity in the range of 2% to 3%. The in-vitro study performed in simulated body fluid (SBF) solution indicates that the microwave-assisted surface modified layer of SS-316L alloy exhibited an improved bioactivity. The SEM images indicate the formation of apatite layer in the modified layer of SS-316L alloy. The observed biological improvements in the microwave-assisted modified layer was due to the cladding induced changes in the surface morphology and surface chemistry of the SS-316L substrate material.

Applications of biopolymer coatings in biomedical engineering

“…These polymer coatings provide powerful functions to the materials they are applied to, whether they are straightforward coatings or nanoparticle-incorporated, functionalized composite coatings. It has potential applications in a wide range of materials, including metals, ceramics, polymers, and nanoparticles, among others [3][4][5][6][7][8][9][10]. In the realm of biomedicine, polymeric coatings play an important part in the development of the future generation of biomaterials and equipment.…”

“…They have a number of potential applications, including resistance to corrosion [7,8,[11][12][13], functionalization of the surface [1,2], resistance to wear [14][15][16][17][18][19][20], enhancement of bioactivity [3,21,22], and even potential usage as switchable smart materials. The most recent development in the field of polymer coatings is the use of smart polymer coatings.…”

Machinability behavior of human implant materials

“…Ti and its alloys hold good wear and corrosion-resistant properties, but their machinability is a quite tough task [4,5,7,[39][40][41][42][43][44][45]. Y 2 O 3 , yttria-stabilized-zirconia (YSZ), HAP and ZrO 2 are the most widely used for bio-implant applications [35,[46][47][48][49][50][51].…”

“…Stainless steel has higher erosion and corrosion resistance [17][18][19][20][21][22][23][24][25][26][27]. Co-Cr alloys have high wear and corrosion resistance as well as have ease of machinability [28][29][30][31][32][33][34][35][36][37][38]. Ti and its alloys hold good wear and corrosion-resistant properties, but their machinability is a quite tough task [4,5,7,[39][40][41][42][43][44][45].…”

“…Ti and its alloys hold good wear and corrosion-resistant properties, but their machinability is a quite tough task [4,5,7,[39][40][41][42][43][44][45]. Y 2 O 3 , yttria-stabilized-zirconia (YSZ), HAP and ZrO 2 are the most widely used for bio-implant applications [35,[46][47][48][49][50][51].This research refers to the function of the biocompatible metals used most often in biomedical applications. These metals are considered to be biocompatible.…”