SEM Analysis Of Fracture In Tensile Testing Of Kenaf/PP Composite Material Produced By 3D Printing

Subaidy, Mohammad Daffa Ulhaq (2026) SEM Analysis Of Fracture In Tensile Testing Of Kenaf/PP Composite Material Produced By 3D Printing. Other thesis, Institut Teknologi Sepuluh Nopember.

Text 5007211220-Undergraduate_Thesis.pdf - Accepted Version Restricted to Repository staff only Download (5MB) | Request a copy

Abstract

Komposit polipropilena berpenguat serat kenaf (kenaf/PP) merupakan alternatif yang ringan dan berkelanjutan terhadap komposit sintetis, namun pemanfaatannya pada teknologi 3D printing masih terkendala sifat mekanik yang tidak konsisten akibat lemahnya ikatan antara serat dan matriks serta adanya void. Penelitian ini mengkarakterisasi permukaan patahan spesimen kenaf/PP hasil pengujian tarik untuk mengidentifikasi karakteristik kegagalan mikrostruktur, faktor yang berkaitan dengan ketidakkonsistenan kekuatan tarik, dan mekanisme patahan yang dominan. Permukaan patahan diamati secara kualitatif menggunakan Scanning Electron Microscopy (SEM), sedangkan fraksi void dikuantifikasi dari citra mikroskop digital melalui thresholding manual pada perangkat lunak ImageJ terhadap 59 pengukuran. Pengamatan SEM menunjukkan adanya fibre pull-out, interfacial debonding, deformasi matriks, serta daerah void yang tidak terkonsolidasi, yang mengindikasikan lemahnya antarmuka serat–matriks. Spesimen 5 wt% cenderung menunjukkan fibre pull-out yang lebih ekstensif dan serpihan kenaf yang terlepas, sedangkan spesimen 3 wt% menunjukkan serat yang tetap tertanam serta deformasi matriks yang ulet, yang mengindikasikan pembasahan serat–matriks yang lebih baik pada kandungan serat yang lebih rendah. Analisis regresi linier sederhana menunjukkan tren menurun yang signifikan secara statistik antara fraksi void dan kekuatan tarik (β₁ = −0,394), dan ketidakkonsistenan kandungan void pada parameter cetak yang sama sejalan dengan ketidakkonsistenan kekuatan tariknya. Spesimen optimal 3 wt% mencapai kekuatan tarik 23,575 MPa, sedangkan spesimen terendah 5 wt% 15,014 MPa. Mekanisme patahan yang dominan adalah fibre pull-out yang disertai interfacial debonding.
===========================================================================================================================================
Kenaf fibre-reinforced polypropylene (kenaf/PP) offers a lightweight and sustainable alternative to synthetic composites, yet its use in 3D printing is limited by inconsistent mechanical properties arising from weak fibre matrix bonding and the presence of voids. This study characterises the fracture surfaces of tensile-tested kenaf/PP specimens in order to identify the microstructural failure features, the factors associated with the inconsistency of tensile strength, and the dominant fracture mechanism. The fracture surfaces were examined qualitatively using scanning electron microscopy (SEM), while the void fraction was quantified from digital-microscope images through manual thresholding in ImageJ across 59 measurements. SEM observation revealed fibre pull-out, interfacial debonding, matrix deformation, and unconsolidated void regions, indicating a relatively weak fibre matrix interface. The 5 wt% specimens tend to exhibit more extensive fibre pull-out and loose kenaf debris, whereas the 3 wt% specimens show fibres that remain embedded together with ductile matrix deformation, indicating better fibre matrix wetting at the lower fibre loading. A simple linear regression showed a statistically significant decreasing trend between void fraction and tensile strength (β₁ = −0.394), and the inconsistency of void content among specimens produced under the same printing parameters corresponds with the inconsistency of their tensile strength. The optimal specimen 3 wt% reached a tensile strength of 23.575 MPa, whereas the lowest-performing specimen 5 wt% reached 15.014 MPa. The dominant fracture mechanism is fibre pull-out accompanied by interfacial debonding.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	3D printing, Fracture surface, Kenaf/PP composite, SEM, Void fraction, 3D printing, Fraksi void, Komposit kenaf/PP, Permukaan patahan, SEM.
Subjects:	H Social Sciences > HD Industries. Land use. Labor > HD9999.C715-.C7154 Composite materials T Technology > TP Chemical technology > TP1140 Polymers
Divisions:	Faculty of Industrial Technology > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	Mohammad Daffa Ulhaq Subaidy
Date Deposited:	29 Jul 2026 01:47
Last Modified:	29 Jul 2026 01:47
URI:	http://repository.its.ac.id/id/eprint/139481

Actions (login required)

View Item