Yus Erny Amirah Mohd Yusof creator author. text my 2023 2023 monographic eng xiii, 69 pages : illustrations 30 cm. + 1 CD-ROM Brazing technique via heat source has been employed in joining the pure copper. Brazing parameters and laser power are crucial factors in determining the joint quality during indirect laser brazing. This research investigated the effects of laser power on brazing temperature, temperature evolution, brazing phases, the strength of the joints, filler spreadability and surface fracture on copper alloys. The brazing process was carried out in a vacuum chamber with a constant vacuum pressure of 400 Pa over 66 seconds for each sample to ensure that the filler metals were melted completely. Cu-78.3Ni-9.9Sn-4.0P-7.9 (MBF2002) was used as a filler metal to braze the Cu/ Cu joints. When the laser power varied from 30 W to 50 W, the brazing temperature increased gradually, hence creating a temperature profile where the brazing phases were identified. With increasing the laser power, the tensile shear strength of the joint also increased. The maximum value of shear strength (159.27 MPa) was obtained at 50 W of laser power compared with another laser power. The shear strength increased by 34.02%. The fracture surfaces were examined under an optical microscope and 3D measuring laser microscope to observe the filler spreadability and surface roughness. It showed that the roughness increases as the laser power increases. The fracture surface occurred at the filler metal and characterized by brittle fracture. In addition, the EDX was carried out for the 50 W laser power sample to identify the microstructure and phase composition of joint interfacial. The microstructure consisted of Cu (Sn- rich) and a Cu-Ni-P phase formed at the brazed joint. Based on the results, the actual process that occurs behind the laser brazing are known through the brazing phases involved. specialized Yus Erny Amirah Mohd Yusof Faculty of Mechanical and Automotive Engineering Technology Thesis (Master of Science) -- Universiti Malaysia Pahang – 2023 Includes bibliographical references Faculty of Mechanical and Automotive Engineering Technology Dissertations Universities and colleges Dissertations Theses THE0009672 (Local) UMP 230720 20251125110754.0 eng