A operação de uma turbina hidráulica para hidrogeração alocada em um rio com sedimentos pode levar ao desgaste erosivo e, consequentemente, manutenção prematura do componente. Visando mitigar esse problema, em geral, aplicam-se revestimentos que aumentam a vida útil das turbinas, mas não eliminam o desgaste erosivo ocorrido, o que leva à necessidade de reparo do componente. O reparo se inicia com a remoção do revestimento remanescente e reconstituição da geometria por solda, para então, reaplicação de um novo revestimento. Nem sempre as regiões afetadas são grandes, o que possibilitaria a aplicação de um reparo por soldagem e também reparo de revestimento localizado na turbina. O reparo sobre o revestimento pode ser aplicado tanto na recuperação de componentes que sofrem desgaste erosivo, bem como, para consertar problemas ocorridos durante o processo de revestimento anterior. O presente trabalho visa compreender e verificar a possibilidade de reparo em um revestimento de WC-10Co-4Cr executado pelo processo de aspersão térmica HVOF (high velocity oxy fuel), bem como, suas limitações em desgaste erosivo. O estudo foca na preparação sobre um revestimento existente (remoção eletroquímica) e aplicação de uma nova camada. Como avaliação inicial o trabalho considerou o ensaio de desgaste erosivo, onde foi encontrado aumento de 22% na quantidade de material erodido nos corpos de prova com reparo. A observação e comparação dos corpos de prova com e sem reparo, utilizando microscopia eletrônica de varredura (MEV), mostra que a diferença em desgaste está na delaminação entre camadas devido à falha coesiva, a qual pôde ser observada através do ensaio de adesão. A falha coesiva pode ser explicada com base em análise por EDS dos corpos de prova, por intermédio da qual foi verificado um aumento na quantidade de oxigênio e, consequentemente, presença de óxido na preparação superficial por remoção eletroquímica. / The operation of a hydraulic turbine for hydropower generation located in a river with sediments can lead to erosive wear, and, as a consequence, premature maintenance of the component. In order to minimize such problem, coatings are applied to increase turbine lifetime, but they do not eliminate erosive wear, which leads to the necessity of component repair. The repair starts with the removal of the remaining coating and reconstitution of the geometry by welding, and then reapplication of a new coating. The affected regions are not necessarily large, which would allow the application of a localized repair by welding and localized repair by coating. The coating repair can be applied in two situations: recovery of components with erosive wear and to fix problems during coating manufacturing. The present work aims to understand and verify the possibility of repair in a WC-10Co-4Cr coating performed by the thermal spraying HVOF process (high velocity oxy fuel), as well as, its limitations in erosive wear. This study focuses in the preparation of an existing coating (electrochemical removal) and application of new coating layers. The start point was an evaluation using an erosion test rig, which indicated an increase of 22% in material removal for the test samples with repair. Using scanning electron microscope (SEM), the test samples with and without repair were compared and showed a wear difference related to delamination between layers due to cohesive failure, which was also observed in the adhesion test. The cohesive failure can be explained by EDS, where it was found a high content of oxygen in the repaired zones, and, as a consequence, presence of oxide in the surface preparation by electrochemical removal.

Please read the abstract in the section 00front of this document / Dissertation (MSc (Chemistry))--University of Pretoria, 2007. / Chemistry / unrestricted

Die Anzahl neurodegenerativer Erkrankungen nimmt in unserer Gesellschaft stetig zu. Obwohl inzwischen eine Reihe genetischer Ursachen identifiziert worden sind, wird auch der Einfluss von Umweltfaktoren bei der Pathogenese dieser Erkrankungen zunehmend in Betracht gezogen. Der Beitrag von ultrafeinen Partikeln aus Industrie und Umwelt auf neurodegenerative Erkrankungen steht daher zunehmend im Fokus der Forschung. Die Translokation von ultrafeinen Partikeln bzw. Nanopartikeln ins Gehirn ist bekannt. Die Charakterisierung neuro- und gliotoxischer Wirkungen von Nanopartikeln in einem in vitro System war deshalb Ziel dieser Arbeit. Untersucht wurden Wolframcarbid-Partikel mit und ohne Cobalt, die im Herstellungsprozess von Hartmetallen von Bedeutung sind. Die meisten toxikologischen Daten wurden bisher mit mikrokristallinen WC-Pulvern an Lungenzellen bzw. -gewebe erhoben. Da aber die Verarbeitung von nanoskaligen Partikeln bessere Eigenschaften der Hartmetalle bewirkt, nimmt das Interesse an toxikologischen Studien mit WC-Nanopartikeln zu. Da die Gefahr der Translokation und Akkumulation im Gehirn beim Einatmen von Stäuben am Arbeitsplatz besteht, wurde erstmalig die Toxizität von WC-NP mit und ohne Cobalt auf Zellen des Gehirns untersucht. Für die Durchführung wurden primäre Neuronen, Astrozyten und Mikroglia sowie die Oligodendrozyten-vorläuferzelllinie OLN-93 der Ratte eingesetzt. Alle untersuchten Partikel konnten mittels Elektronenmikroskopie, ICP-Massenspektrometrie und Durchflusszytometrie in den verschiedenen Zelltypen nachgewiesen werden. Untersuchungen mit Cytochalasin D (Inhibitor der Aktinpolymerisation) deuteten auf zell- und partikelspezifische Aufnahmemechanismen hin. Experimente mit Cobaltchlorid und Natriumwolframat konnten beweisen, dass nicht die gelösten Ionen für die Toxizität von WC-Co ursächlich waren, sondern die Partikelform von entscheidender Bedeutung ist. Es zeigte sich jedoch, dass einige der WC-Co verursachten Effekte vermutlich auf dem Cobaltanteil beruhen. Offensichtlich dienen WC-Co-NP als Vehikel, um Cobalt in die Zellen einzuschleusen. Zur toxischen Wirkung trägt auch das Reaktionsvermögen von WC und Cobalt an der beiderseitigen Grenzfläche bei, denn dadurch können in der Zelle vermehrt reaktive Sauerstoffspezies gebildet werden. Im Rahmen der Untersuchungen wurden die zeit- und konzentrationsabhängigen Effekte der Nanopartikelexposition auf die Vitalität, die Proliferation, das Adhäsionsverhalten, das mitochondriale Membranpotential und die Induktion apoptotischer und nekrotischer Zelluntergänge untersucht. Dabei wurden verschiedene Vitalitäts- und Proliferationstests angewendet, um die häufig beobachteten Wechselwirkungen zwischen Reagenzien und Nanopartikeln auszuschließen. Nicht alle untersuchten Nanopartikel erwiesen sich in den durchgeführten Experimenten als akut toxisch. Nur eine Exposition mit WC-Co-NP führte nach 72 h zu einer deutlich verringerten Vitalität und Proliferation bei Astrozyten und OLN-93 Zellen. Eine Exposition mit WC-Co-NP zeigte des Weiteren eine geringe Induktion von Apoptose und Nekrose bei Astrozyten, nicht aber bei OLN-93 Zellen. Neurone wiesen nach einer Exposition mit NP eine wenig verringerte Vitalität auf. Es wurde festgestellt, dass erst die primäre Schädigung von Astrozyten zu einer sekundären Neuronenschädigung führt. Bei der Bewertung der NP-Toxizität müssen daher unbedingt die Wechselwirkungen der Zellen bedacht werden. Die Exposition mit WC- und WC-Co-NP beeinflusste das mitochondriale Membranpotential und das Adhäsionsverhalten der untersuchten Zellen. Neuronen und OLN-93 Zellen zeigten nach NP-Exposition eine verminderte Adhäsion. Auch physiologische Kalziummessungen lieferten einen Hinweis für die veränderte Funktionalität glialer Zellen nach einer NP-Exposition. Des Weiteren wurde die Expression einiger Gene, bedeutend für Adhäsion und extrazelluläre Matrix, mit realtime RT-PCR bei OLN-93-Zellen und Astrozyten überprüft. Es konnte eine Regulation von Mmp9, Timp1, Lama3, Tgfbi, Col8a1 und Hmox1 gezeigt werden. Zusammenfassend lässt sich feststellen, dass die ausgewählten Nanopartikel nicht per se neuro- und gliotoxisch wirkten. Die Partikel können anhand abnehmender Toxizität wie folgt geordnet werden: WC-Co > WC 100na > WC 10n. Auch die Reaktionen der Zellen fielen unterschiedlich aus: die Astrozyten erwiesen sich als die sensitivsten Zellen. Eine Exposition des Gehirns mit WC-Co-NP in hohen Konzentrationen oder über einen längeren Zeitraum könnte also weit reichende Folgen haben, angefangen bei einer gestörten Signalweiterleitung über eine erhöhte Permeabilität der Blut-Hirn-Schranke bis hin zu neurodegenerativen Veränderungen. Diese und weitere Untersuchungen könnten bei der Erstellung von Arbeitsrichtlinien im Umgang mit Hartmetallen, deren Ausgangsmaterial nanoskalige Pulver sind, hilfreich sein und damit einen Beitrag zum Schutz der Arbeiter liefern.

No description available.

Plasma centrifugal atomization is a method widely used in the production of spherical powders of metals and alloys with relatively low melting points. A novel plasma centrifugal atomization process suitable for high melting point materials (i.e. 3500 ᵒC and above) was developed by Metasphere Technology AB, currently Höganäs Sweden AB. In this process, feedstock material in the form of crushed powder with particle sizes in the range 400-1000 µm is fed into a rotating crucible and subsequently melted by the glow discharge of a plasmatron. Due to high rotational speeds, a melt film forms at the edge of the crucible and breaks into fine droplets that are ejected into the reactor chamber and solidified in a whirl of cold inert gases. Capability of the plasmatron to reach very high temperatures, combined with extremely rapid cooling of the ejected droplets, allow for the fabrication of fine powders of refractory alloys exhibiting metastable phases that cannot be obtained otherwise.  Oil drilling, ore processing and metal shaping applications, among other, require tool materials capable of withstanding harsh working conditions under heavy loads. Owing to their physical, chemical and mechanical properties, tungsten-carbon alloys are among the most suited materials for such applications. Melting followed by rapid solidification of tungsten-carbon mixtures with 3.9 wt.% C results in a biphasic structure composed of WC lamellae inserted in a W2C matrix, known as cast tungsten carbide (CTC). Due to the metastable nature of both phases present, CTC exhibits exceptional mechanical properties. CTC is mainly used as reinforcing dispersed phase in metal matrix composite hardfacing overlays, which are deposited by plasma transferred arc (PTA) welding or laser cladding onto steel tools. High-entropy alloys (HEAs) are defined as multi-component solid solutions with equimolar or near-equimolar concentration of all principal elements. Owing to their outstanding mechanical, corrosion, erosion, oxidation and radiation resistance properties compared to conventional alloys, HEAs are among the most suited materials for aerospace and nuclear applications. Several processing routes have allowed for laboratory-scale production of HEAs. Nevertheless, size and shape of bulk components that can be thus produced are largely limited. In a quest for up-scaling the processing of high-end bulk HEA components, plasma centrifugal atomization of pre-alloyed refractory HEA spherical powders suitable for additive manufacturing was envisaged. In this work, capabilities of the novel plasma centrifugal atomization for processing of refractory alloys into fine spherical powders have been evaluated based on two different material systems, namely CTC and a refractory HEA containing Ti, V, Zr, Nb, Mo, Hf, Ta, W. Challenges of local mechanical characterization of micron-sized powders have been addressed and a robust method for testing of individual particles has been developed. Mechanical properties such as hardness and fracture toughness of plasma atomized CTC powders have been extensively investigated and related to the corresponding thermal stories. Experimental results suggest significant straining of the crystal lattice in the case of as-atomized CTC, possibly due to extremely high cooling rates experienced by the solidifying particles. This has been ruled out the main reason for the outstanding mechanical properties of plasma atomized CTC compared to both spheroidized CTC and conventional cast & crushed CTC. Effective stress relieve was possible upon heat treatment. Plasma atomization of the refractory HEA yielded similar results, where an extremely fine microstructure with no noticeable chemical segregation was obtained. Indentation hardness of this novel microstructure was found to be approximately 25% higher than that of similar alloys reported in literature. HEA powder thus produced was then consolidated into bulk HEAs with very simple geometries, proving that this powder can be further processed into components of more or less complexity for pre-defined applications.

Commercially important hydrogenation reactions make use of precious noble metal catalysts which are becoming increasingly scarce, and the search for capable alternative catalysts prevails. Transition metal carbides of group IV-VI metals show similar catalytic behavior to platinum and are $103/kg lower in price than the precious metal catalysts. Tungsten carbide, studied in this work, can form in different stoichiometries and phase compositions depending upon synthesis methods. Synthesis of high surface area tungsten carbide with control over its phase composition remains a challenge currently. In this work, the novel isothermal synthesis method of tungsten carbide (WC, W2C) in a CH4/H2 carburization atmosphere with synthesis temperature and presence or absence of a silica support in the catalyst precursor (WO3) as process variables was investigated. The amounts of CO and H2O formed during synthesis corresponded to the amount of oxygen in the WO3 precursor. The catalysts were further characterized by X-ray diffraction to determine phase composition and crystallite size, by scanning electron microscopy to determine morphology, and by CO chemisorption to determine metallic surface area. X-ray diffraction analysis indicated the carbide catalysts to contain W2C, WC, and metallic W phases. The use of a silica-supported precursor favored the formation of a nearly phase pure, high surface area W2C rich catalyst whereas high synthesis temperature and absence of silica precursor favored formation of a low surface area WC rich catalyst. Further, the catalysts were tested for steady state activity at a W/F (weight catalyst/toluene feed rate) of 0.20-0.30 h-1, addition of H2 to a total pressure of 21 bar absolute and 250 °C, and the effect of phase composition and surface area on the activity was studied. This work resulted in the successful synthesis of 4 tungsten carbide catalysts with varying phase compositions and surface areas and correlation of their compositions and surface areas with their corresponding toluene hydrogenation activities.

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: The purpose of this study is to investigate the machinability of commercially pure (CP) titanium, manufactured using the press-and-sinter PM process. To this end, CP titanium powder (-200 mesh) was compacted and sintered in vacuum (10-4 torr) for two hours at 1200°C. Small cylindrical samples were compacted at pressures varying from 350 to 600 MPa in order to determine the compressibility of the powder. Following these tests, four larger stepped-cylinder samples were compacted at pressures close to 400 MPa and sintered under similar conditions. These samples had sintered densities varying between 3.82 and 4.41 g/cm3. They were used to evaluate the machinability of the sintered titanium using face turning machining tests. The samples were machined dry, using uncoated carbide (WC-Co) cutting tool. Cutting speeds between 60-150 m/min were evaluated while keeping the feed rate and depth of cut constant at 0.15 mm/rev and 0.5 mm, respectively. The final machined surface finish and the tool wear experienced during the face turning machining tests were monitored in order to evaluate PM titanium’s machining performance. This study showed that it is possible to use the press-and-sinter PM process with CP titanium powder, with a particle size of less than 75 μm (-200 mesh), to manufacture sintered titanium. However, particle shape influences the compressibility of the powder and pressing parts of larger volume, such as the machining test sample shape, is challenging when using such small particle size powder. Processing conditions, such as compaction pressure, sintering temperature and sintering time, influence the sintered density. Results from the machinability tests show that tool wear increases with a decrease in the porosity of the sintered titanium. A more porous sintered material has both lower strength and thermal conductivity. As these factors have opposing effects on the machinability of materials, it is concluded that the strength of the sintered titanium has a stronger influence on its machinability than the thermal conductivity. The cutting tool wear was uniform but showed indications of crater wear. The machined surface of the denser parts had minimal defects compared to less dense parts. Chip shape is long for the dense parts, and spiral for the less dense parts. The chips formed were all segmented, which is typical for titanium. The machinability of the sintered CP titanium was compared to that of wrought titanium alloys. As expected, it was found that the machinability of the sintered titanium was poor in comparison. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie is om die masjineerbaarheid van kommersieel suiwer (KS) titaan, wat deur die pers-en-sinter poeiermetallurgie (PM) metode vervaardig word, te ondersoek. Om hierdie doel te bereik, is KS titaan poeier (-200 ogiesdraad) gekompakteer en gesinter in ‘n vakuum (10-4 torr) teen 1200°C vir 2 ure. Klein silindriese monsters is tussen drukke van 350en 600 MPa gekompakteer om die samedrukbaarheid van die poeier te bepaal. Na aanleiding van hierdie toetse, is vier groter trapvormige-silinder monsters by drukke naby aan 400MPa gekompakteer en onder soortgelyke omstandighede gesinter. Hierdie monsters het gesinterde digthede tussen 3.82 en 4.41 g/cm3 gehad. Hulle is gebruik om die masjineerbaarheid van die gesinterde titaan te ondersoek deur middel van vlak-draai masjineringstoetse. Die monsters is sonder smeermiddel gemasjineer met onbedekte karbied (WC-Co) snygereedskap. Snysnelhede tussen 60 – 150 m/min is geëvalueer terwyl die voertempo en diepte van die snit konstant by 0.15 mm/rev en 0.5 mm, onderskeidelik, gehou is. Die finale gemasjineerde oppervlak afwerking en gereedskapsslytasie tydens die vlak-draai masjinering toets is van die faktore wat gemonitor is sodat PM titaan se optrede tydens masjinering geëvalueer kan word. Hierdie studie wys dat diepers-en-sinter metode wel met KS titaan poeier, met ‘n partikel grootte van minder as 75 μm (-200 maas), gebruik kan word om gesinterde titaan te vervaardig. Die partikelgrootte beïnvloed wel die samedrukbaarheid van die poeier. Die samedrukking van parte met groter volume, soos bv die masjinerings toetsmonster, is uitdagend wanneer klein partikelgrootte poeier gebruik word. Proses omstandighede, soos kompaksie druk, sinteringstemperatuur en sinteringstyd, beïnvloed die gesinterde digtheid. Resultate van die masjineerbaarheidstoetse wys dat beitelslytasie toeneem met ‘n afname in porositeit van die gesinterede titaan. ‘n Meer poreus gesinterde materiaal het beide laer sterkte en termiese geleidingsvermoë. Aangesien hierdie faktore teenoorgestelde uitwerkings op masjineerbaarheid het, word dit dan afgelei dat die sterkte van gesinterde titaan ‘n groter invloed het op sy masjineerbaarheid as die termiese geleidingsvermoë. Die beitel se slytasie is hoofsaahlik, maar het tekens van kraterslytasie getoon. Die gemasjineerde oppervlak van die meer digte onderdele of toetsmonters het min gebreke gehad in vergelyking met die minder digte dele. Die vorm van die spaanders is lank vir digte parte, en spiraalvormig vir minder digte toetsmonsters. Die spaanders wat gevorm het, was almal gesegmenteerd, wat tipies is vir titaan. Die masjineerbaarheid van die gesinterde KS titaan is met dié van gesmede titaanallooie vergelyk. Soos verwag is, is gevind dat die masjineerbaarheid van die gesinterde titaan in vergelyking swak is.

Wear resistant surfaces with high toughness and impact resistant properties are to be created to improve the life cycle cost of brake discs for trains. A potential solution to this industrial problem is to use an arc cladding process. This work describes the application of gas tungsten arc welding (GTAW) for a structural ceramic Metal Matrix Composite (MMC) on steel. The structure of the two ceramics examined indicates the possibility of development of a wear resistant surface, which would extend the life of the brake disc. Silicon Carbide (SiC) and Tungsten Carbide (WC) ceramics were studied to embed them in a steel matrix by an advanced GTAW method. WC particles penetrated the liquid weld pool and also partially dissolved in the steel matrix, whereas, SiC because of the physical properties never penetrated deeper into the weld pool but segregated on the surface. Successful embedding and bonding of WC led to the decision to exercise an in-depth analysis of the bonding between the WC particles and the matrix. Chemical analysis of the matrix revealed more WC dissolution as compared to particle form within the clad. It was observed that WC reinforcement particles built a strong chemical bond with the steel matrix. This was shown by electron backscatter diffraction (EBSD) analysis. The hard clad layer composed of WC reinforced steel matrix gave an matching friction coefficient to high-strength steel in cold wear conditions through Pin-on-Disc wear and friction testing. A prototype railway brake disc was created with the established GTAW parameters to find out the difficulties of producing industrial scale components.

Na indústria hidrometalúrgica, diversos materiais são utilizados para a construção dos equipamentos, a fim de satisfazer as necessidades dos processos que estão sujeitos, tendo em conta a importância deles em condições complexas, tais como erosão e a corrosão. Neste trabalho é avaliado o comportamento de um aço inoxidável martensítico AISI 410 tratado termicamente com têmpera e revenimento, frente aos revestimentos Carbeto de Tungstênio (86WC-10Co4Cr) obtido por aspersão térmica (High Velocity Oxygen Fuel-HVOF), e um elastômero PUR comercial MetaLine 785 em condições de desgaste do tipo lama, analisando a perda de volume, a determinação da área e profundidade erodida das amostras, para os ângulos de incidência de 30∘ e 90∘ entre o eixo de simetria do fluxo do fluido e a superfície das amostras. Os ensaios foram realizados para os diferentes tipos de materiais em um equipamento para ensaios simulados de lama, desenvolvido como parte da pesquisa no LACER (Laboratório de Materiais Cerâmicos) da Universidade Federal do Rio Grande do Sul (UFRGS), sob controle de parâmetros como ângulo de impacto e sua velocidade, temperatura de ensaio e concentração de partículas erosivas na suspensão, neste caso foi usada alumina eletrofundida ALO marrom da companhia Treibacher. Realizou-se a caracterização dos materiais, na sua microestrutura Microscopia Eletrônica de Varredura (MEV), Microscopia Óptica (M.O), espessura, rugosidade, porosidade, microdureza e estruturalmente na identificação de fases Difração de Raios X (DRX), Espectroscopia por Energia Dispersiva (EDS), o analise térmico Perda ao Fogo (LOI) para o caso do elastômero PUR, e a distribuição de tamanho de partícula (LG) e morfologia para o erodente. Com a pesquisa conseguiu-se estabelecer as relações entre o desgaste erosivo por lama e as propriedades físicas relacionadas aos materiais avaliados, nas condições estabelecidas no ensaio de erosão do equipamento, e concluiu-se que o revestimento de 86WC-10Co4Cr carbeto de Tungstênio apresentou uma melhor resistência ao desgaste erosivo tipo lama, em comparação com o aço inoxidável martensítico AISI 410 e o elastômero PUR comercial MetaLine 785. / In the hydrometallurgical industry, many materials are used in the construction of the equipment in order to satisfy the needs of the processes to which they are subjected, taking into account their importance in complex conditions such as erosion and corrosion. In this work, the behavior of a quenched and tempered AISI 410 martensitic stainless steel is compared to tungsten carbide (86WC-10Co4Cr) obtained by thermal spray (High Velocity Oxygen Fuel - HVOF) and to a commercial elastomer PUR MetaLine 785 under slurry erosion conditions. Volume loss, area determination and eroded depth of the samples were analyzed at angles of incidence of 30∘ and 90∘ between the axis of symmetry of the fluid flow and the surface of the samples. The tests were carried out for the different types of materials in a slurry erosion simulation device, developed as part of the research in LACER (Laboratory of Ceramic Materials) of the Federal University of Rio Grande do Sul (UFRGS), via the control of parameters such as angle and speed of impact, test temperature and concentration of erosive particles in the suspension. In this case, electrofused brown ALO alumina (Treibacher) was used. The materials were characterized with regard to their microstructure (SEM), thickness, roughness, porosity, microhardness, structure in the phase identification (DRX) (EDS), thermal analysis (LOI) in the case of the PUR elastomer and the particle size distribution (LG) and morphology for the erodent. The research was able to establish the relationships between the slurry erosive wear and the physical properties related to the evaluated materials, under the conditions established in the erosion test of the equipment. It was concluded that the coating 86WC-10Co4Cr tungsten carbide presented better resistance to the slurry erosion wear when compared to AISI 410 martensitic stainless steel and the PUR commercial elastomer MetaLine 785.

Thesis (MScEng (Industrial Engineering))--University of Stellenbosch, 2009. / The titanium alloys have found wide application in the aerospace, biomedical and automotive industries. Soaring fuel prices and environmental concerns are the fundamental drivers that intensify the demand situation for titanium. From a machining viewpoint, one of the challenges companies face, is achieving high material removal rates while maintaining the form and function of the part. The ultimate aim for a machining business remains to make parts quickly. Conventional cutting speeds range from 30 to 100 m/min in the machining of Ti-6Al-4V. Milling this alloy faster however is challenging. Although titanium is becoming a material of choice, many of the same qualities that enhance titanium‟s appeal for most applications also contribute to its being one of the most difficult materials to machine. The author explored the potential for Polycrystalline diamond (PCD) inserts in high speed milling of Ti-6Al-4V, by trying to understand the fundamental causes of tool failure. The objective was to achieve an order of magnitude increase in tool life, while machining at high speed, simply by reducing some of the failure mechanisms through different cutting strategies. Tool wear is described as a thermo-mechanical high-cycle fatigue phenomenon. The capability of a higher material removal per tool life is achieved in the case of PCD inserts compared to Tungsten carbide (WC). The average surface roughness produced was relatively low. The collected chips were also analyzed. The work demonstrated progress over the performance reported in current literature. The work confirms that there is a region where a sufficiently high temperature in the cutting zone may contribute to extended tool life, provided that the tool material can withstand these extreme conditions.