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Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting
Mthembu, N. B. 2025. Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/6cf8b06d-ac4a-49a3-9017-efc3cc47708c
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Stellenbosch : Stellenbosch University
2025
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| _version_ | 1867613912195661824 |
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| access_status_str | Open Access |
| author | Mthembu, Noluthando Bright |
| author2 | Sacks, Natasha |
| author_browse | Mthembu, Noluthando Bright Sacks, Natasha |
| author_facet | Sacks, Natasha Mthembu, Noluthando Bright |
| author_sort | Mthembu, Noluthando Bright |
| collection | Thesis |
| dc_rights_str_mv | Stellenbosch University |
| description | Mthembu, N. B. 2025. Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/6cf8b06d-ac4a-49a3-9017-efc3cc47708c |
| format | Thesis |
| id | oai:scholar.sun.ac.za:10019.1/132257 |
| institution | Stellenbosch University (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:43:40.919Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository |
| publishDate | 2025 |
| publishDateRange | 2025 |
| publishDateSort | 2025 |
| publisher | Stellenbosch : Stellenbosch University |
| publisherStr | Stellenbosch : Stellenbosch University |
| record_format | dspace |
| source_str | SUNScholar — Stellenbosch University Repository |
| spelling | oai:scholar.sun.ac.za:10019.1/132257 Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting Mthembu, Noluthando Bright Sacks, Natasha Stellenbosch University. Faculty of Engineering. Dept. of Industrial Engineering. Titanium alloys -- Mechanical properties Metallic composites Additive manufacturing UCTD Mthembu, N. B. 2025. Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting. Unpublished masters thesis. Stellenbosch: Stellenbosch University [online]. Available: https://scholar.sun.ac.za/items/6cf8b06d-ac4a-49a3-9017-efc3cc47708c Thesis (MEng)--Stellenbosch University, 2025. ENGLISH ABRATACT: Ti6Al4V is a titanium (Ti) alloy with notable properties that has been used in a wide spectrum of industries but suffers from poor hardness and wear resistance. Various investigations have been conducted to alleviate this issue by introducing reinforcing materials into the alloy’s matrix through different conventional processing methods, and as of recent, additive manufacturing (AM) processing techniques. The aim of this study was to determine the feasibility of fabricating a titanium metal matrix composite (MMC) by reinforcing the Ti6Al4V alloy matrix with tungsten carbide (WC) particles and produce the composite through the selective laser melting (SLM) process. To accomplish this, a logical set of objectives were followed including a comprehensive review and understanding of the area of interest, the materials properties and their compatibility, the AMprocess with special focus on SLM and its critical parameters, and post-treatment processing employed for Ti6Al4V matrix composites. Additionally, a response surface methodology (RSM) was employed to systematically generate and optimize deposition parameters, followed by printing via SLM and characterization of the materials’ properties including density, micro-hardness, microstructural and phase evolution, and tensile strength properties. Material characterization was carried out through Optical Microscopy, Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), X-ray diffraction (XRD) and CT-scanning on the transverse and longitudinal view to the build direction of the printed cuboids. A 10 wt.% fraction of WC was added to Ti6Al4V, and this was the primary MMC investigated in this study. After determining the alloy’s scanning strategy that yielded the highest relative density of 99.7 %, with the machines default parameters of 95 W and 600 mm/s, optimization of the composite’s laser power and scanning speed was carried out, it was identified that the highest density of 5.01 g/cm3 (equivalent to ~90 % relative density) was attained at 200 W and 960 mm/s. With the 10 wt.% WC addition, the materials Vickers micro-hardness increased by ~28 % and ~24 % in the longitudinal and transverse sections, respectively. Post heat treatment, the alloy exhibited an ultimate tensile strength (UTS), yield strength and % elongation of 1092 ±12 MPa, 1059 ±11 MPa and 12.4 %, respectively. These properties conform to the tensile properties in the standard specification of Ti alloys via powder bed fusion (PBF). While the UTS of the composite was 1112 ±26 MPa, the % elongation was low at 4.4 %. Further investigation was conducted on the Ti6Al4V reinforced with 20 wt.% WC. The optimal deposition parameters for this new composition were determined using Simufact. Due to the cracking of the tensile samples printed through SLM, tensile testing could not be carried out. AFRIKAANSE OPSOMMING: Ti6Al4V is 'n titaanlegering met noemenswaardige eienskappe wat in 'n wye spektrum van nywerhede gebruik word, maar ly aan swak hardheid en weerstand teen slytasie. Verskeie ondersoeke is uitgevoer om hierdie probleem te adresseer deur versterkingsmateriaal in die legering se matriks in te voer deur middel van verskillende konvensionele verwerkingstegnieke, en onlangs ook deur aditatiwe vervaardigingstegnieke. Die doel van hierdie studie was om Ti6Al4Vlegeringmatriks met wolfraamkarbied (WC)-partikels te versterk en die komposiet deur middel van die selektiewe laser- smelt (SLM) proses te produseer. ‘n Logiese reeks doelwitte gevolg om die doel te bereik, insluitend 'n omvattende hersiening en begrip van die belangstellingsgebied, die materiaaleienskappe en hul verenigbaarheid, die byvoeglike vervaardigingsproses met spesiale fokus op selektiewe laser-smelting en sy kritieke parameters, en naverwerking wat gebruik word vir Ti6Al4V-metaalmatrikskomposiete. 'n responsoppervlakmetodologie (RSM) is gebruik om optimale deposisie parameters te verkry. Daar na is die monsters gedruk deur gebruik te maak van SLM. Karakterisering van die materiaaleienskappe, insluitend digtheid, mikrohardheid, mikrostruktuur- en fase-ontwikkeling, en treksterkte-eienskappe is voltooi. MAteriaalkarakterisering is uitgevoer deur optiese mikroskopie, skandeer-elektronmikroskopie en energie-verspreidings-spektroskopie, X-straal diffraksie en CTskandering op die dwars- en lengte-aansig van die gedrukte kubusse. 'n 10 wt.% fraksie wolfraamkarbied is bygevoeg tot Ti6Al4V, en dit was die primêre metaalmatrikskomposiet wat in hierdie studie ondersoek is. Na die bepaling van die legering se skanderingstrategie wat die hoogste relatiewe digtheid van 99.7 % lewer, met krag van 95 W en spoed van 600 mm/s, is optimalisering van die komposiet se laserskrag en skanderingsspoed uitgevoer. Dit is vasgestel dat die hoogste digtheid van 5.01 g/cm3 (ekwivalent aan ~90 % relatiewe digtheid) bereik is by 200 W en 960 mm/s. Met die 10 wt.% WC-byvoeging het die materiaal se mikrohardheid met ~28 % en ~24 % in die lengte- en dwarsseksies onderskeidelik toegeneem. Na naverhitting het die legering 'n maksimum treksterkte, verlenging van 1092 ±12 MPa, 1059 ±11 MPa en 12.4 % onderskeidelik getoon. Hierdie eienskappe voldoen aan die treksterkte-eienskappe in die standaardspesifikasie van titaanlegerings via poeierbedsmelting. Terwyl die maksimum treksterkte van die komposiet 1112 ±26 MPa was, was die verlenging reltief laag 4.4 %. Verdere ondersoek is uitgevoer op die Ti6Al4V versterk met 20 wt.% WC. Die optimale neerslagparameters vir hierdie nuwe samestelling is bepaal deur Simufact te gebruik. As gevolg van die kraak van die trekmonsters wat deur SLM gedruk is, kon trektoetse nie uitgevoer word nie. Masters 2025-06-02T05:44:22Z 2025-06-02T05:44:22Z 2025-03 Thesis https://scholar.sun.ac.za/handle/10019.1/132257 en Stellenbosch University xv, 109 pages : illustrations application/pdf Stellenbosch : Stellenbosch University |
| spellingShingle | Titanium alloys -- Mechanical properties Metallic composites Additive manufacturing UCTD Mthembu, Noluthando Bright Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting |
| title | Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting |
| title_full | Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting |
| title_fullStr | Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting |
| title_full_unstemmed | Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting |
| title_short | Feasibility study on the reinforcement of Ti6Al4V with tungsten carbide particles using selective laser melting |
| title_sort | feasibility study on the reinforcement of ti6al4v with tungsten carbide particles using selective laser melting |
| topic | Titanium alloys -- Mechanical properties Metallic composites Additive manufacturing UCTD |
| url | https://scholar.sun.ac.za/handle/10019.1/132257 |
| work_keys_str_mv | AT mthembunoluthandobright feasibilitystudyonthereinforcementofti6al4vwithtungstencarbideparticlesusingselectivelasermelting |