Mohd. Mustafa Al Bakri Abdullah
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Preferred name
Mohd. Mustafa Al Bakri Abdullah
Official Name
Abdulah, Mohd. Mustafa Al Bakri
Alternative Name
Abdullah, M.M.A.
M.M.A. Abdullah
Mustafa Al Bakri, A. M.
Albakri Abdullah, M. M.
Main Affiliation
CeGeoGTech UniMAP
Scopus Author ID
53164519100

Research Output
Now showing 1 - 3 of 3
  • Publication
    Effect of NaOH molar concentration on microstructure and compressive strength of Dolomite/Fly Ash-Based geopolymers
    ( 2021)
    Emy Aizat Azimi
    ;
    M.A.A. Mohd Salleh
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Ikmal Hakem A. Aziz
    ;
    Kamarudin Hussin
    ;
    Jitrin Chaiprapa
    ;
    Petrica Vizureanu
    ;
    Sorachon Yoriya
    ;
    Marcin Nabiałek
    ;
    Jerzy J. Wyslocki
    Dolomite can be used as a source of aluminosilicate to produce geopolymers; however, this approach is limited by its low reactivity. This study analyzes the viability of producing geopolymers using dolomite/fly-ash with sodium silicate and NaOH solutions (at multiple concentrations) by determining the resultant geopolymers’ compressive strengths. The dolomite/fly-ash-based geopolymers at a NaOH concentration of ~22 M resulted in an optimum compressive strength of 46.38 MPa after being cured for 28 days, and the SEM and FTIR analyses confirmed the denser surface of the geopolymer matrix. The synchrotron micro-XRF analyses confirmed that the Ca concentration exceeded that of Si and Mg, leading to the formation of calcium silicate hydrate, which strengthens the resulting geopolymers.
  • Publication
    Role of sintering temperature in production of nepheline Ceramics-Based geopolymer with addition of ultra-high molecular weight polyethylene
    ( 2021)
    Romisuhani Ahmad
    ;
    Fakhryna Hannanee Ahmad Zaidi
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Wan Mastura Wan Ibrahim
    ;
    Jitrin Chaiprapa
    ;
    Kamarudin Hussin
    ;
    Jerzy J. Wysłocki
    ;
    Katarzyna BÅ‚och
    ;
    Marcin Nabiałek
    The primary motivation of developing ceramic materials using geopolymer method is to minimize the reliance on high sintering temperatures. The ultra-high molecular weight polyethylene (UHMWPE) was added as binder and reinforces the nepheline ceramics based geopolymer. The samples were sintered at 900 °C, 1000 °C, 1100 °C, and 1200 °C to elucidate the influence of sintering on the physical and microstructural properties. The results indicated that a maximum flexural strength of 92 MPa is attainable once the samples are used to be sintered at 1200 °C. It was also determined that the density, porosity, volumetric shrinkage, and water absorption of the samples also affected by the sintering due to the change of microstructure and crystallinity. The IR spectra reveal that the band at around 1400 cm−1 becomes weak, indicating that sodium carbonate decomposed and began to react with the silica and alumina released from gels to form nepheline phases. The sintering process influence in the development of the final microstructure thus improving the properties of the ceramic materials.
      8  10
  • Publication
    Influence of 1.5 wt.% Bi on the microstructure, hardness, and shear strength of Sn-0.7Cu solder joints after isothermal annealing
    ( 2021)
    Mohd Izrul Izwan Ramli
    ;
    Mohd Arif Anuar Mohd Salleh
    ;
    Andrei Victor Sandu
    ;
    Siti Farahnabilah Muhd Amli
    ;
    Rita Mohd Said
    ;
    Norainiza Saud
    ;
    Mohd. Mustafa Al Bakri Abdullah
    ;
    Petrica Vizureanu
    ;
    Adam Rylski
    ;
    Jitrin Chaiprapa
    ;
    Marcin Nabialek
    This manuscript reports the isothermal annealing effect on the mechanical and microstructure characteristics of Sn-0.7Cu-1.5Bi solder joints. A detailed microstructure observation was carried out, including measuring the activation energy of the intermetallic compound (IMC) layer of the solder joints. Additionally, the synchrotron µX-ray fluorescence (XRF) method was adopted to precisely explore the elemental distribution in the joints. Results indicated that the Cu6Sn5 and Cu3Sn intermetallic layers thickness at the solder/Cu interface rises with annealing time at a rate of 0.042 µm/h for Sn-0.7Cu and 0.037 µm/h for Sn-0.7Cu-1.5Bi. The IMC growth’s activation energy during annealing is 48.96 kJ mol-1 for Sn-0.7Cu, while adding Bi into Sn-0.7Cu solder increased the activation energy to 55.76 kJ mol−1. The µ-XRF shows a lower Cu concentration level in Sn-0.7Cu-1.5Bi, where the Bi element was well dispersed in the β-Sn area as a result of the solid solution mechanism. The shape of the IMC layer also reconstructs from a scallop shape to a planar shape after the annealing process. The Sn-0.7Cu hardness and shear strength increased significantly with 1.5 wt.% Bi addition in reflowed and after isothermal annealing conditions.
      1  31