Rheology effect and enhanced thermal conductivity of diamond/metakaolin geopolymer fabricated by direct ink writing

Abstract

Purpose Traditional simulation research of geological and similar engineering models, such as landslides or other natural disaster scenarios, usually focuses on the change of stress and the state of the model before and after destruction. However, the transition of the inner change is usually invisible. To optimize and make models more intelligent, this paper aims to propose a perceptible design to detect the internal temperature change transformed by other energy versions like stress or torsion. Design/methodology/approach In this paper, micron diamond particles were embedded in 3D printed geopolymers as a potential thermal sensor material to detect the inner heat change. The authors use synthetic micron diamond powder to reinforced the anti-corrosion properties and thermal conductivity of geopolymer and apply this novel geopolymer slurry in the direct ink writing (DIW) technique. Findings As a result, the addition of micron diamond powder can greatly influence the rheology of geopolymer slurry and make the geopolymer slurry extrudable and suitable for DIW by reducing the slope of the viscosity of this inorganic colloid. The heat transfer coefficient of the micron diamond (15 Wt.%)/geopolymer was 50% higher than the pure geopolymer, which could be detected by the infrared thermal imager. Besides, the addition of diamond particles also increased the porous rates of geopolymer. Originality/value In conclusion, DIW slurry deposition of micron diamond-embedded geopolymer (MDG) composites could be used to manufacture the multi-functional geological model for thermal imaging and defect detection, which need the characteristic of lightweight, isolation, heat transfer and wave absorption.

Thermal conductivity of several geopolymer composites and discussion of their formulation

“…[23][24][25] Most work reported on metakaolin GP composite thermal conductivity has involved adding materials or structural features, including glass microspheres, 26 polystyrene (PS), 27,28 cork, 29 mineral particles, 30 rubber disks, 31 and induced porosity, [32][33][34][35][36][37][38] to improve their insulating ability. On the other hand, only few fillers have been evaluated in metakaolin GP composites for increased thermal conductivity (quartz, 39 SiC, 40 graphene nanoplatelets [GNPs], 41 carbon nanotubes [CNTs], 42 diamond, 43 and calcite 44 ). Waste materials to increase the thermal conductivity of GP composites have also not yet been tested.…”

Microscopic Mechanism of Tunable Thermal Conductivity in Carbon Nanotube-Geopolymer Nanocomposites

“…Cho 18 found that the thermal conductivity of the GP can be increased by 22% when adding 3 wt % of graphene nanoplatelets to potassium geopolymer. Wang et al 14 added 15 wt % of diamond powder to GP by using 3D printing technology, which increased its thermal conductivity by 47.85%.…”

“…Due to the nature of the amorphous structure, there is strong phonon scattering during the thermal transport process, leading to low thermal conductivity. However, this greatly limits the application of GP in geothermal drilling, 12 molten salt storage system, 13 nuclear waste coating, 14 etc, which usually requires high thermal conductivity to improve energy efficiency, while low-temperature gradients reduce the thermal stress. 15 At present, research progress has been reported in enhancing the thermal conductivity of GP, mainly by adding high thermal conductivity nanofillers including quartz, 16 SiC, 17 graphene nanoplatelets, 18 diamond powder, 14 carbon nanotubes (CNTs), 2 etc.…”

Possibilities of Additive Technologies for the Manufacturing of Tooling from Corrosion-Resistant Steels in Order to Protect Parts Surfaces from Thermochemical Treatment

“…Nowadays, one of the most promising areas of AM is the manufacturing of products from metal powders by the laser beam powder bed fusion (LB-PBF) and direct metal deposition (DMD) [2][3][4][5]. The range of materials used is expanding, along with the widespread use of corrosion-resistant steels; research is underway to determine the optimal parameters for the manufacture of products such as ceramics, metal alloys and composite materials [6][7][8].…”

“…The authors of Reference [8] consider shot blasting to reduce stresses and structural defects as a post-processing of specimens made of corrosion-resistant 316L steel by laser cladding. It is shown that the surface stress of the specimen formed by the hybrid process changed from tensile to compressive stress.…”