PT Journal AU Bricin, D Spirit, Z Strejciu, J Kriz, A TI Effect of Laser Shock Peening and Hot Isostatic Pressing on the Microstructure of MoNiCr Nickel Based Alloy SO Manufacturing Technology Journal PY 2025 BP 582 EP 588 VL 25 IS 5 DI 10.21062/mft.2025.074 DE LSP; HIP; MoNiCr; Laser Shock Peening; Hot Isostatic Pressing AB This study aimed to evaluate the change in the microstructure of MoNiCr nickel-based alloy because of specimen surface modification by laser shock peening (LSP) followed by heat treatment using the hot isostatic pressing technology (HIP). Specimens which were cut from casted ingot had 7 mm in thickness and 117 mm in diameter. LSP surface modification was performed in a 60x60 mm square grid on the central part of each of them. Different values of laser power density in combination with or without tape or underwater condition were used for that operation. Specimens were then cut in half. One part each of them was left in LSP surface treatment conditions, and the other was heat-treated using HIP. Heat treatment was done in an argon atmosphere using 1050 °C temperature and 120 MPa pressure. Several microscopy techniques were used to evaluate changes in specimen's microstructure caused by LSP and HIP. Optical profilometer was used to evaluate change in surface roughness. Op-tical and scanning electron microscopes were used to evaluate surface microstructural changes caused by LSP and HIP. Metallography analysis was supplemented by HV0.01 microhardness measurement. The results of the experiment showed that LSP caused plastic deformation of the surface, which in-creased with the applied laser energy density and the number of passes. Microhardness increased due to LSP to a depth of 0.7 mm from the specimen's surface. The HIP process caused decrease in surface hardness and recrystallization of the grains structure in some cases ER