Effect of agro‐waste pore formers on the microstructure, hardness, and tensile properties of porous alumina ceramics

Abstract

This study demonstrates a simple and economically viable approach to fabricate porous alumina ceramics shaped with low-priced natural organic pore-forming agents (PFAs) from rice husk (RH) and sugarcane bagasse (SCB) of various weight contents using the powder metallurgy method. Experimental findings revealed that the total porosity (44-67vol%) and average pore size (70-178 lm) maintained a linear relationship with rising PFA inclusion. Using the diametral compression test, the mechanical response of porous alumina samples was evaluated as a function of porosity and pore geometry. From the overall mechanical strength characterization, the susceptivity of strength on porosity became well marked as the agro-waste shaped porous ceramics exhibited hardness, tensile strength, and elastic modulus of 529.1-26HV, 20.4-1.5MPa and 1662-57MPa, respectively. Moreover, the fractography of the RH and SCB graded porous alumina samples was evaluated as a function of the respective microstructural features. With a plausible tradeoff between pore interconnectivity and mechanical strength, recommended areas of application include solid oxide fuel cells (SOFCs) design, filtration, and thermal insulation systems. K E Y W O R D S agro-waste PFA, hardness, porosity, porous alumina, tensile strength

The circular economy of agro and post‐consumer residues as raw materials for sustainable ceramics

“…4 In particular, regarding ceramic materials, several scientific works propose agro-industrial residues in tiles, bricks, cements, foam glasses, bioceramics, geopolymers, etc. [5][6][7][8][9][10][11][12][13][14][15][16][17] Looking at chemical composition and calorific power of agro residues, exists the real possibility of exploiting both the organic component to create lightening and to low the firing temperature, and the inorganic ones, represented for example by the presence of specific elements useful for a functionalization (eg, presence of phosphorus into cattle bone flour ash available for a fertilizer effect). In this specific area that the research of the authors, aimed at making ceramic products, has been developed in the past and present years.…”

Use of a kaolinitic‐illitic clay from Central African Republic and an organic waste for the production of porous ceramic materials

“…Besides, some authors have pointed out the potential use of such wastes for manufacturing various materials 1,2 . In recent years, the incorporation of agricultural or plant wastes has been investigated particularly regarding the manufacturing of ceramic products 3–15 . Obviously, the use of plant wastes would promote pore development within ceramics during the firing or sintering process, due to their chemical degradation and related evolved gases.…”

“…In general, these porous ceramics are suitable candidates for overcoming some environmental and energy issues, 17,18 in the fields of heterogeneous catalysis and chemical separation. The use of organic residues in brick production to obtain porous ceramic bodies with enhanced insulating properties was studied by several authors 4,5,9,11,13,19 . Clays, the basic raw material in the manufacture of such ceramic products, exhibited various chemical and mineralogical characteristics that would significantly influence the final properties of use at the industrial scale.…”

Effect of the plant waste onto the properties of use and the microstructure of phyllosilicates based ceramics

“…In recent years, several research papers have been published regarding the study of incorporating biomass into mineral materials for the production of ceramics and building materials 14‐21 . In some cases, the results show that the incorporation of this type of alternative raw material has a double advantage, in addition to the recovery of this waste, it can also promote the properties of the materials obtained 22‐26 .…”