Fracture and Embedment Behavior of Brittle Submicrometer Spherical Particles Fabricated by Pulsed Laser Melting in Liquid Using a Scanning Electron Microscope Nanoindenter

Abstract

Generally, hard ceramic carbide particles, such as B4C and TiC, are angulated, and particle size control below the micrometer scale is difficult owing to their hardness. However, submicrometer particles (SMPs) with spherical shape can be experimentally fabricated, even for hard carbides, via instantaneous pulsed laser heating of raw particles dispersed in a liquid (pulsed laser melting in liquid). The spherical shape of the particles is important for mechanical applications as it can directly transfer the mechanical force without any loss from one side to the other. To evaluate the potential of such particles for mechanical applications, SMPs were compressed on various substrates using a diamond tip in a scanning electron microscope. The mechanical behaviors of SMPs were then examined from the obtained load–displacement curves. Particles were fractured on hard substrates, such as SiC, and fracture strength was estimated to be in the GPa range, which is larger than their corresponding bulk bending strength and is 10–40% of their ideal strength, as calculated using the density-functional theory. Contrarily, particles can be embedded into soft substrates, such as Si and Al, and the local hardness of the substrate can be estimated from the load–displacement curves as a nanoscale Brinell hardness measurement.

Recent Advances in Nanomechanical Measurements and Their Application for Pharmaceutical Crystals

“…; therefore it is desirable to develop a genuine mechanical property of composites involved in formulation. To understand how individual particles compress or fracture, the indentation based microcompression tests can be utilized. − A flat punch or a large conospherical indenter has been used for such measurements. Along with indentation, having a complementary imaging technique such as optical or electron microscope facilitates proper sample–particle alignments and one can also visualize how the particles deform or fracture in real-time .…”

Advanced Boron Carbide Matrix Nanocomposites Obtained from Liquid-Charge: Focused Review

“…Spherically shaped SMPs (SubMicrometer Particles), even those of these hard carbides, can be prepared by heating raw particles dispersed in a liquid using an instantaneous pulsed laser. In [91], the porous-free SMPs were compressed on SiC hard substrates using an SEM (Scanning Electron Microscope) diamond tip. The mechanical behavior of boron carbide SMPs was examined from the load-displacement curves.…”

Advances in Micro- and Nanomechanics

“…Properties of nanoparticles and related composites were investigated in [7,8]. Fracture strength and local hardness of spherical particles made of B 4 C and TiC were estimated in [7].…”

“…Properties of nanoparticles and related composites were investigated in [7,8]. Fracture strength and local hardness of spherical particles made of B 4 C and TiC were estimated in [7]. In [8], nanoparticles of NiO/C applied for the manufacturing of nanocomposites for supercapacitors were investigated using X-ray diffraction and other techniques.…”