Orientador: Adriano Wagner Ballarin / Banca: Luiz Antonio Targa / Banca: Ivaldo de Domenico Vareli / Banca: João Alberto Borges de Araujo / Banca: Nilson Franco / Resumo: A propriedade mecânica denominada dureza é largamente utilizada na especificação de materiais, nos estudos e pesquisas mecânicas e metalúrgicas e no controle de qualidade de diversos materiais. No caso particular da madeira, dentre as diversas propriedades mecânicas empregadas como ferramentas para avaliação da sua qualidade e de seu potencial tecnológico, tem destaque a dureza Janka, que avalia a relação entre uma força de penetração superficial de uma pequena esfera de aço na madeira e a endentação promovida por essa esfera. Constitui-se em ensaios simples, rápido, e com boas correlações com a resistência à compressão paralela às fibras da madeira, referência maior na classificação estrutural deste material. Mais recentemente, trabalhos internacionais reportaram o uso da dureza Brinell para avaliação de madeiras. Além das vantagens já reportadas para a dureza Janka, a dureza Brinell traria a facilidade de realização dos ensaios em condições de campo, sobretudo pela menor magnitude dos esforços envolvidos na cravação do endentador na superfície do material. Dando continuidade a estudos já desenvolvidos, este trabalho teve como objetivo estudar critérios ou práticas, aplicáveis no campo e em exemplares individuais, para a qualificação mecânica de algumas espécies de madeira com a finalidade de classificação, e aprovação ou reprovação de lotes de dormentes de madeira para uso ferroviário. Os estudos iniciais conduziram ao projeto e desenvolvimento de equipamento 2 para avaliação em campo da dureza de madeiras - Durômetro portátil para madeiras embasado, no geral, na metodologia Brinell com mensuração dos diâmetros da calota endentada no material sob análise. Os ensaios de teste funcional e de calibração do equipamento foram conduzidos utilizando-se 16 lotes de madeiras de reflorestamentos e nativas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The mechanical property called hardness is largely used in material specifications, in mechanical and metallurgical studies and research and in the quality control of several kinds of materials. Specifically for timber, among the several mechanical properties used as tools for its quality control and technological potential, Janka hardness, which evaluate the relation between a superficial penetration force of a small steel sphere in wood and the indentation produced by such sphere, are highlighted. It is constituted by simple, quick and easily performed test, with good correlations with the compression parallel to grain strength, a high reference in structural classification for this material. More recently, international studies have reported the use of Brinell hardness for timber assessment. Besides the advantages previously mentioned for Janka hardness, the Brinell one would make it easier to perform the tests in field conditions, especially for its lower magnitude in terms of the involved loads. Continuing studies already developed with such property for timber, this work had the objective of studying criteria or practices applicable on field and in individual wood elements, for the mechanical qualification of some timber species towards its classification, and approval or failing of timber sleeper lots for rail usage. The initial studies led to the project and development of an equipment for timber hardness field evaluation - portable Hardometer for timber. 4 The functional and calibration test of the equipment were carried out using 16 native and exotic timber lots, among there E.citriodora, E. tereticornis, E. saligna, E. urophylla, E. grandis, Goupia glabra (Cupiúba) and Bagassa guianenses (Tatajuba), with variation of origins beyond species. Each lot had 12 specimens. The calibration tests, performed with timber on its moisture above the FSP (fiber saturation point)... (Complete abstract click electronic access below) / Doutor

O objetivo deste trabalho foi avaliar a dureza e o módulo de elasticidade da região de adesão quando utilizados diferentes sistemas adesivos e uma resina composta imediatamente após o procedimento adesivo e após 6 meses de armazenamento, correlacionando esses valores com a resistência adesiva à dentina humana. Para isso foram medidos a dureza e o módulo de elasticidade da resina composta junto à área de união, da camada de adesivo, da camada híbrida, e da dentina adjacente utilizando testes de nanoendentação. Foram utilizados 40 molares humanos hígidos (n=10). Os dentes foram preparados de modo a obterem-se superfícies planas em dentina, sobre as quais os sistemas adesivos foram aplicados seguindo as instruções dos fabricantes. Foram utilizados quatro sistemas adesivos de diferentes formas de aplicação (Adper Scotchbond Multiuso, Adper Single Bond 2, Adper SE Plus e Clearfil SE Bond). Sobre essas superfícies foram inseridos incrementos de resina composta perfazendo 5 mm de altura. Após 24h de armazenamento em água destilada à 37ºC. Os dentes restaurados foram seccionados para obterem-se corpos-de-prova com área aderida de 1mm2. Dos corpos de prova viáveis, 2 palitos centrais de cada dente foram selecionados para análise da nanodureza e do módulo de elasticidade da interface adesiva. Os demais tiveram a resistência de união testada através do teste de microtração, sendo metade desses corpos de prova armazenados durante 6 meses em água à 37ºC. Foi aplicado o teste estatístico ANOVA para dois fatores para todas as variáveis do estudo. Para o fator tempo foi detectada diferença estatística entre os grupos para a resistência adesiva (p=0,042), para o módulo de elasticidade do adesivo (p=0,000) e nanodureza do adesivo (p=0,000), sendo os valores mais baixos observados após 6 meses de armazenamento. Para o fator adesivo, todos os grupos apresentaram diferenças estatísticas (p=0,000), exceto para a variável nanodureza da camada híbrida (p=0,255). O sistema adesivo Clearfil SE Bond apresentou os melhores valores para resistência adesiva e módulo de elasticidade da camada híbrida, juntamente com o sistema Scothbond Multiuso. Os piores desempenhos foram demonstrados pelo sistema adesivo Adper SE Plus. Para a interação, apenas a variável nanodureza do adesivo apontou diferença entre os grupos (p=0,028). O teste de correlação de Pearson detectou correlação significante para as variáveis de módulo de elasticidade, sendo negativa para o módulo de elasticidade do adesivo e positiva para o módulo de elasticidade da camada híbrida. A metodologia e os resultados apresentados permitem-nos concluir que as propriedades mecânicas estudadas (resistência adesiva, módulo de elasticidade do sistema adesivo e da camada híbrida, nanodureza do sistema adesivo e da camada híbrida) podem variar dependendo do sistema adesivo utilizado e do tempo de armazenamento após o procedimento adesivo ter sido realizado. Além disso, quanto maior o módulo de elasticidade da camada híbrida apresentado por um sistema adesivo maior será sua resistência adesiva e menor será o módulo de elasticidade apresentado pela camada de adesivo. / The aim of this study is to evaluate hardness and elasticity module of adhesive region of adhesive systems of different formulations immediately and 6 moths after the adhesive procedures. Those values will be compared to microtensile bond strength to human dentin. The hardness and elasticity module of composite resin next to adhesion region, adhesive layer, hybrid layer and dentin were evaluated. Forty sound human molars were used and prepared in order to obtain flat dentin surfaces in which the adhesive systems were applied following manufactures instructions (n=10). The groups were divided according the four adhesive systems: Adper Scotchbond Multipurpose, Adper Single Bond 2, Adper SE Plus and Clearfil SE Bond. Resin blocks of 5mm were constructed in those surfaces. After 24h of storage in distilled water at 37°C restored teeth were sectioned in order to obtain specimen with a bonded area of around 1mm2. Two specimen of each tooth were submitted to nanohardness and elasticity module test of adhesive interface. Half of the specimen were immediately submitted to the test with a crosshead speed of 0,5mm/min until fracture, the other specimen were stored for additional 6 month in 37ºC water prior to the test. The values resulting of all variables of the study were compared using ANOVA two-way. For the time factor, it was detected statiscal difference between groups in microtensile bond strength values (p=0,042), adhesive elastic modulus (p=0,000) and adhesive nanohardnes (p=0,000), the lowest values were observed in 6 months of storage. For adhesive factor, all groups presented statistical difference (p=0,000), except hybrid layer nanohardness (p=0,255). Clearfil SE bond and Scothbond systems presented the best values of bond strength and hybrid layer elastic modulus. The worse performance was demonstrated by Adper SE Plus adhesive system. For the interaction, only the adhesive nanohardness presents difference between groups (p=0,028). The Pearson correlation test detected positive correlation with microtensile bond strength tests and hybrid layer elastic modulus and negative correlation with bond strength and adhesive elastic modulus. The methodology and the results allow us to conclude that the studied mechanical properties (bond strength, modulus of elasticity of the adhesive and hybrid layer, nanohardness adhesive system and the hybrid layer) may vary depending on the adhesive system and time storage after the bonding procedures have been performed. Moreover, when an adhesive system presents a high elastic modulus of hybrid layer, it will present a high bond strength and low elastic modulus of adhesive layer.

No description available.

Thesis (M.Sc. (Chemistry)) -- University of Limpopo, 2022 / Calcium and magnesium are two dominant species that contribute to water hardness. The aim of this study was to develop a poly (vinylidene fluoride-co hexafluoropropylene) (PVDF-HFP) composite membrane for treatment of water hardness. The synthesis of PVDF-HFP composite membranes was confirmed by X ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The concentrations of the hardness causing agents in both the simulated and real hard water samples were investigated in batch studies wherein parameters such as pH, contact time, temperature, and adsorbent were optimised. The maximum adsorption efficiency of 56 and 45 mg/g (evaluated by Langmuir isotherm) for Ca(II) and Mg(II) ions were obtained. These were achieved at an optimum pH of 7 and adsorption dosage of 0.5 mg/L using the 3% PVDF-HFP/cellulose acetate (CA) and 1% nitrogen doped multiwalled carbon nanotubes (N-MWCNTs)/CA composite membranes respectively. The adsorption kinetics and isotherm models were all consistent with the pseudo-second order and Freundlich isotherm models for all the membranes suggesting that the sorption process met heterogeneous adsorption. Furthermore, the thermodynamic parameters indicated that the adsorption is physical and endothermic in nature. Reusability studies showed that all the PVDF-HFP based membranes can be recycled at least 3 times and for Ca(II) ions an adsorption loss of only 0.35 % was recorded while using a 3% PVDF-HFP/CA composite membrane. These results were further confirmed by XRD, TGA and inductively coupled plasma mass (ICP-MS) spectrometry. Thus, the findings from this study have shown that the PVDF-HFP based membranes could provide valuable material for hardness removal to acceptable level.

Indiana University-Purdue University Indianapolis (IUPUI) / Background: Interim restoration for a lost anterior tooth is often needed for temporary esthetic and functional purposes. Materials for interim restorations usually have less strength than ceramic or gold and can suffer from fracture. Several approaches have been proposed to reinforce interim restorations, among which fiber reinforcement has been regarded as one of the most effective methods. However, some studies have found that the limitation of this method is the poor polymerization between the fibers and the composite resin, which can cause debonding and failure. 64 Purpose: The purpose of this study was to investigate the effects of different polymerization methods as well as fiber types on the mechanical behavior of fiberreinforced composite resin. Material and Methods: A 0.2-mm thick fiber layer from strip fibers or mesh fibers embedded in uncured monomers w as fabricated with polymerization (two-step method) or without polymerization (one-step method), on top of which a 1.8-mm composite layer was added to make a bar-shape sample, followed by a final polymerization. Seventy-five specimens were fabricated and divided into one control group and four experimental groups (n=15), according to the type of glass fiber (strip or mesh) and polymerization methods (one-step or two-step). Specimens were tested for flexural strength, flexural modulus, and microhardness. The failure modes of specimens were observed by scanning electron microscopy (SEM). Results: The fiber types showed significant effect on the flexural strength of test specimens (F = 469.48; p < 0.05), but the polymerization methods had no significant effect (F = 0.05; p = 0.82). The interaction between these two variables was not significant (F = 1.73; p = 0.19). In addition, both fiber types and polymerization steps affected the flexural modulus of test specimens (F = 9.71; p < 0.05 for fiber type, and F = 12.17; p < 0.05 for polymerization method). However, the interaction between these two variables was not significant (F = 0.40; p = 0.53). Both fiber types and polymerization steps affected the Knoop hardness number of test specimens (F = 5.73; p < 0.05 for polymerization method. and F = 349.99; p < 0.05 for fiber type) and the interaction between these two variables was also significant (F = 5.73; p < 0.05). SEM images revealed the failure mode tended to become repairable while fiber reinforcement was 65 existed. However, different polymerization methods did not change the failure mode. Conclusion: The strip fibers showed better mechanical behavior than mesh fibers and were suggested for use in composite resin reinforcement. However, different polymerization methods did not have significant effect on the strength and the failure mode of fiber-reinforced composite

Master of Science / Department of Grain Science and Industry / Jeffrey A. Gwirtz / Variation in wheat kernel hardness is influenced by several factors including genetic expression and environmental conditions. However, these factors explain only a portion of the observed variation. Thus, there are unknown contributors to this important physical property. The following experiments investigated growing locations between farms and within the spike as a source of variation. Four commercial varieties of Hard Red Winter (HRW) wheat were chosen for evaluation; Jagger, Jagalene, Overley, and 2137. In total, 374 wheat spikes were collected from three farms participating in the Kansas State University Research and Extension- 2007 Crop Performance Tests (KSCPT). For analyses, each kernel was removed and cataloged by spikelet and floret position. A total of 10,240 kernels were uniquely identified by variety, farm, plot, spike, spikelet and floret position. Using the single kernel characterization system (SKCS), kernels were crushed to determine the hardness, diameter, weight, and moisture content. The variability of each measured attribute was greatest between spikes of a given variety. Measured attributes exist in gradients along the spike, with the top and bottom portions being most variable. This research broadens our knowledge of wheat kernel variation, and results from this experiment may contribute to improved methods for single kernel analysis.

Résumé: Le développement de l’industrie des polymères fourni de plus en plus de choix pour la formulation de matériaux pour les couvre-planchers. Les caoutchoucs, le PVC et le linoleum sont les polymères habituellement utilisés dans l’industrie des couvre-planchers. Ce projet répond à un problème de facilité de nettoyage des couvre-planchers de caoutchouc qui sont reconnus pour être mous, collants et ayant une surface rugueuse. L’INTRODUCTION couvrira l’état actuel de la recherche sur les couvre-planchers, surtout en regard au problème de la «nettoyabilité». La théorie pertinente et les informations générales sur les polymères, les composites polymériques et la science des surfaces seront introduites au CHAPITRE 1. Ensuite, le CHAPITRE 2 couvrira la méthode utilisée pour déterminer la nettoyabilité, l’évaluation des résultats ainsi que l’équipement utilise. Le CHAPITRE 3, discutera des premières expériences sur l’effet de la mouillabilité, la rugosité et la dureté sur la facilité de nettoyage des polymères purs. Plusieurs polymères ayant des surfaces plus ou moins hydrophobes seront investigués afin d’observer leur effet sur la nettoyabilité. L’effet de la rugosité sur la nettoyabilité sera investigué en imprimant une rugosité définie lors du moulage des échantillons; l’influence de la dureté sera également étudiée. Ensuite, un modèle de salissage/nettoyage sera établi à partir de nos résultats et observations afin de rationaliser les facteurs, ou « règles », qui détrminent la facilité de nettoyage des surfaces. Finalement, la réticulation au peroxyde sera étudiée comme une méthode de modification des polymères dans le but d’améliorer leur nettoyabilité; un mécanisme découlant des résultats de ces études sera présenté. Le CHAPITRE 4 étendra cette recherche aux mélanges de polymères; ces derniers servent habituellement à optimiser la performance des polymères purs. Dans ce chapitre, les mêmes tests discutés dans le CHAPITRE 3 seront utilisés pour vérifier le modèle de nettoyabilité établi ci-haut. De plus, l’influence de la non-miscibilité des mélanges de polymères sera discutée du point de vue de la thermodynamique (DSC) et de la morphologie (MEB). L’utilisation de la réticulation par peroxyde sera étudié dans les mélanges EPDM/ (E-ran-MAA(Zn)-ran-BuMA) afin d’améliorer la compatibilité de ces polymères. Les effets du dosage en agent de réticulation et du temps de cuisson seront également examinés. Finalement, un compatibilisant pré-réticulé a été développé pour les mélanges ternaires EPDM/ (E-ran-MAA(Zn)-ran-BuMA)/ HSR; son effet sur la nettoyabilité et sur la morphologie du mélange sera exposé. / Abstract: The development of industrial polymers provides more choices to the design of flooring materials. Rubbers, PVC and linoeleum are the most used polymers in the flooring industry. This project stems from the problem of cleanability (ease of cleaning) of the surface of rubber tile flooring which is known as a soft, sticky and rough surface. In the introduction, the current situation of research on the polymer flooring industry, especially the study on the cleaning problem will be introduced. The relevant theory and general information on polymers, polymer composites and surface science will be introduced in CHAPTER 1. In CHAPTER 2 different approaches, protocols and equipment to evaluate cleanability will be presented. The initial experiments and results (CHAPTER 3) will involve various fundamental concepts on surface wettability, roughness and hardness, as these properties can all influence the surface soiling and cleanability. In single-polymer systems, dozens of polymer materials with a hydrophobic or hydrophilic surface were investigated to observe their soiling and cleaning properties. The effect of roughness was also studied by surface printing method which is used to control the surface topography. Likewise, the influence of surface hardness on cleanability was also investigated with different polymer materials. From the above results and observations, a surface soiling/cleaning model is proposed in attempt to simplify the ― rules ‖ which determine the surface cleanability. Finally, peroxide crosslinking was investigated as a matrix modification method to improve the surface cleanability. The second part of the experiments and results (CHAPTER 4) extends to investigations of polymer blends, in attempt to optimize the performance of single-polymer materials. In this chapter, the surface cleaning model and its relevant rules are examined by the wettability, roughness and hardness tests discussed in CHAPTER 3. The influence of immiscibility on cleaning performance will be discussed in polymer blends from the point of view of thermodynamics (DSC) and morphology (SEM). In order to improve the compatibility in polymer blends, peroxide crosslinking was performed in EPDM/ (E-ran-MAA(Zn)-ran-BuMA) blends. The dosage of curing (cross-linking) agent and curing time were investigated to observe the influence of these experimental conditions on cleanability. Finally, a blend compatibilizer was designed to improve the compatibility of the EPDM/ (E-ran-MAA(Zn)-ran-BuMA)/HSR blends.The compatibilizer prepared by partial pre-crosslinking of EPDM (Nordel) and E-ran-MAA(Zn)-ran-BuMA (Surlyn) was incorpo rated in polymer composites and its influence on cleanability was studied and explained on the basis of changes in morphology of the blend polymer matrix.

Al 7050-T7451 alloy with good combinations of strength, stress corrosion cracking resistance and toughness, is used broadly in the aerospace/aviation industry for fatigue-critical airframe structural components. However, it is also considered as a highly anisotropic alloy as the crack growth behavior along the short transverse direction is very different from the one in the long transverse direction, due to the inhomogeneous microstructure with the elongated grains distributed in the work material used in the sheet/plate applications. Further processes on these materials are needed to improve its mechanical and material properties and broaden its applications. The material with ultra-fine or nano grains exhibits improved wear and corrosion resistance, higher hardness and better fatigue life, compared to the one with coarse grains. In recent times, the development of novel processing technologies has gained great attention in the research community to enhance the properties of the materials employed in the aerospace, biomedical, precision instrument, automotive, nuclear/power industries. These novel processing technologies modify the microstructure of this alloy and improve the properties. The aim of this dissertation is to investigate the effects of cryogenic processes, including friction stir processing (FSP), machining and burnishing, on Al 7050-T7451 alloy to solve the inhomogeneity issue and improve its surface integrity. FSP is applied to modify the microstructure of Al 7050-T7451 alloy for achieving more homogeneous structure with near ultra-fine grains (UFG) which were less than 2 µm, particularly in cryogenic FSP with liquid nitrogen as the coolant. Approximately 10% increase could be observed from the hardness measurement from the samples processed by cryogenic FSP, in contrast to dry FSP. Also, the texture change from Al (200) to Al (111) could be achieved in all the samples processed by dry and cryogenic FSP. Cryogenic machining and burnishing processes were also applied to enhance the surface integrity of the manufactured components with near-UFG structure. The highest cutting temperature was reduced by up to 44.7% due to the rapid cooling effect of liquid nitrogen in cryogenic machining, compared with dry machining. Nano grains were produced in the refined layers induced by cryogenic burnishing. And, up to 35.4% hardness increase was obtained within the layer depth of 200 µm in the cryogenically-burnished surface. A numerical finite element method (FEM) model was developed for predicting the process performance in burnishing. Less than 10% difference between the experimental and predicted burnishing forces was achieved in the simulation of cryogenic burnishing, and reasonable predictions were also achieved for temperatures, severe plastic deformation (SPD) layers.

Clad alloys feature one or more different alloys bonded to the outside of a core alloy, with non-equilibrium, interalloy interfaces. There is limited understanding of the recovery and recrystallization behaviour of cold rolled clad aluminum alloys. In order to optimize the properties of such alloys, new heat treatment processes may be required that differ from what is used for the monolithic alloys. This study examines the recovery behaviour of a cold rolled Novelis FusionTM alloy containing an AA6XXX core with an AA3003 cladding on one side. The bond between alloys appears microscopically discrete and continuous, but has a 30 m wide chemical gradient. The as-deformed structure at the interalloy region consists of pancaked sub-grains with dislocations at the misorientation boundaries and a lower density organized within the more open interiors. X-ray line broadening was used to extract the dislocation density from the interalloy region and an equivalently deformed AA6XXX following static annealing using a modified Williamson-Hall analysis. This analysis assumed that Gaussian broadening contributions in a pseudo-Voigt function corresponded only to strain from dislocations. The kinetics of the dislocation density evolution to recrystallization were studied isothermally at 2 minute intervals, and isochronally at 175 and 205°C. The data fit the Nes model, in which the interalloy region recovered faster than AA6XXX at 175°C, but was slower at 205°C. This was most likely caused by change in texture and chemistry within this region such as over-aging of AA6XXX . Simulation of a continuous annealing and self homogenization process both with and without pre-recovery indicates a detectable, though small change in the texture and grain size in the interalloy region. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2013-10-02 10:19:10.279

A thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy.‘ Johannesburg, August 2017 / Fe-B-C composites were produced, from boron carbide and iron powders, using spark plasma sintering. This provided information on the effects of rapid sintering on densification, composition and the microstructure of the materials produced. The composition range included a selection high Fe contents (69.3, 78 and 80.9 vol. % Fe-B4C) and high B4C concentrations (1, 3, 5 vol. % Fe-B4C). The properties of the materials were investigated to determine the potential for using relatively cheap Fe and B4C powders to produce hard, wear resistant materials. High Fe-B4C composites were sintered at 900, 1000 and 1100°C at 60 MPa. Densification increased with increasing temperature and at 1100° each composition achieved ≥ 97 % densification. The materials reacted during sintering with the main phases observed being Fe2B and Fe3(B,C) whilst additional phases formed were FeB, C and Fe23(B,C)6.Comparing the phases that were produced to Fe-B-C phase diagrams showed deviations from expected compositions, indicating the non-equilibrium nature of producing the composites using SPS. Although the composites were not at equilibrium, all the B4C reacted and could not be maintained, even with fast heating and cooling rates. The properties of the materials were dependent on both densification and the phases that were present after sintering. Materials containing higher amounts of the Fe2B phase showed higher hardness and fracture toughness results, up to 13.7 GPa and 3.5 MPa.m0.5 respectively for the 69.3 vol. % Fe-B4C. The materials were sensitive to grain and pore growth which negatively affected properties at 1100°C. The transverse rupture strength of 388.3 MPa for 80.9 vol. % Fe-B4C composite was the greatest, and showed evidence of both intergranular and transgranular fracture. The strength was affected by a fine dispersion of porosity at the grain boundaries, throughout the material, and free carbon in the structure was detrimental to the strength of the 69.3 % Fe-B4C. The wear rates were lower using Si3N4 wear balls compared to stainless steel balls, where 69.3 vol. % Fe-B4C showed the best wear rates, 8.9×10-6 mm3/Nm (stainless steel ball) and 1.77×10-6 mm3/Nm (Si3N4 ball), due to the higher Fe2B composition and free carbon acting as a lubricant during sliding. 1, 3 and 5 vol. % Fe-B4C composites were sintered to densities above 97 % of theoretical at 2000°C and 30 MPa. The formation of a transient FeB liquid phase assisted densification. 1 % Fe-B4C attained hardness and fracture toughness up to 33.1 GPa and 5.3 MPa.m0.5 with a strength of 370.5 MPa. Thermal mismatch between the FeB phase and B4C caused high residual stresses at the interface which led to cracking and pull-out of the FeB phase. Residual carbon at the grain boundary interface exacerbated the pull-out effect. Increasing Fe and the subsequent FeB phase had an embrittling effect. The materials suffered severe wear of up to 36.92×10-6 mm3/Nm as a result of the pull-out with the remaining porosity acting as a stress raiser. 20 vol. % of the Fe in each system was substituted with Ti to reduce the presence of residual carbon. Although in some case the properties of the respective compositions improved, residual carbon was still present in the composites. / MT2018