Mechanical properties of laser-deposited composite boride coating using nanoindentation

Abstract

Nanoindentation proves to be an effective technique to measure mechanical properties of "composite" materials, as it has high spatial resolution that enables estimation of properties even from fine grains, particles, and precipitates. The elastic modulus, E, of the composite boride coating deposited on AISI 1010 steel using the laser surface engineering (LSE) process has been computed using the nanoindentation technique. The highest E value of 477.3 GPa was achieved for coating in a sample that contained 0.69 volume fraction of TiB 2 particles in the coating after processing with the highest laser traverse speed of 33 mm/s. A comparison between the theoretical and experimental computation of the elastic modulus suggests that theoretical elastic modulus values are lower than computed elastic modulus, as the latter includes the effect of dissolution of fine TiB 2 particles in Fe matrix and metastable phase formation such as Fe a B b and Ti m B n . Dissolution of fine TiB 2 particles in the Fe matrix in the coating region has been corroborated by transmission electron microscope (TEM) micrographs and corresponding energy-dispersive spectroscope (EDS) analysis and selected area diffraction (SAD) pattern.

The Effective Elastic Modulus of Laser‐Engineered Composite Boride Coating

“…Rule of Mixture (Nano indentation) [13] Rule of Mixture (Literature value) [ Titanium and its alloys are extensively used in aeronautical, marine and chemical industries due to their intrinsic properties such as high strength, good oxidation and corrosion resistance. Nevertheless, the applications of titanium alloys under severe wear conditions are currently restricted due to their low hardness and poor tribological properties.…”

“…[14] The coating, metallurgically bonded to the steel substrate is composite in nature, with TiB 2 particles of various sizes and shapes embedded in Fe-rich matrix. [13,14] The detailed procedure of coating formation is reported elsewhere. [14] Three different TiB 2 coatings (B1, B2, B3) with different volume fraction (0.52, 0.66 and 0.69 respectively, Tab.…”

“…It is assumed that both the TiB 2 particles and the Fe-rich matrix behave linearly elastic during applying load in nanoindentation technique. [13] Benveniste et al found that if the ªtypical inclusionsº are embedded as second phase particulates in the matrix then the Mori-Tanaka stiffness tensor is symmetric. [6] Thus, Mori-Tanaka method can be applied to compute the effective elastic modulus of the composite coating where TiB 2 particle are dispersed in Fe-rich matrix.…”

Evaluation of modulus of elasticity, nano-hardness and fracture toughness of TiB2–TiC–Al2O3 composite coating developed by SHS and laser cladding

“…Very few of the reported investigations [27][28][29] on the evaluation of these properties were carried out on coatings developed by laser technology. Biswas et al [27] calculated the hardness and Young's modulus from a load-displacement graph using the method proposed by Oliver and Pharr for TiN coating on Ti-6Al-4V alloy developed through laser surface nitriding.…”

Avaliação do recobrimento biomimétrico em compósitos de alumina-zircônia texturizadas superficialmente com laser de femtossegundo

“…Engenharia de superfície a laser é um método de processamento de material que utiliza alta densidade de energia de luz focalizada para aquecer ou fundir os materiais com o intuito de gerar modificações próximas à superfície (SEMAK, et al, 1998 (AGARWAL, et al, 2000).…”