The effect of Mg addition on the microstructure, texture, and mechanical performance of two hypoeutectic ZnMg alloys with 0.68 and 1.89 wt% Mg content was studied and compared to pure Zn after extrusion. The SEM/ EDX, EBSD, and XRD investigations were carried out to study the effect of alloying on (1) phases' composition, morphology, and size and (2) crystallography of the grains and the dominating slip systems. Through the mentioned investigations, hypothesized strengthening mechanisms could be estimated to identify the contribution of solid solution, grain boundary, secondary phase, dislocation, and texture rations of strengthening to improve the overall calculated yield strength. Uniaxial tensile testing was performed to evaluate the ultimate tensile strength (UTS), the yield tensile strength (YTS0.2 %), and the elongation to failure (Ef) of the pure and alloyed Zn and to compare the yield tensile strength with the computed ones. The combined impacts of the bimodal grains, the solubility of Mg, favorable morphology and distribution of secondary phase, and weakened bimodal basal texture with simultaneous twin-non basal slip mode deformation mechanisms resulted in an extraordinary strength-ductility synergy of the as extruded Zn-0.68Mg alloy (--326 MPa and --16 %). The current research provides a new pathway for designing high-performance Zn-based alloys as an alternative loadbearing material for orthopedic implant applications.

The demand for innovative materials has been a significant driving force in material development in a variety of industries, including automotive, structural, and biomedical. Even though a tremendous amount of research has already been conducted on metallic, polymeric, and ceramic materials, they all have distinct drawbacks when used as mono-materials. This gave rise to the development of nature-inspired sandwich-structured composite materials. The combination of strong metallic skins with soft polymeric cores provides several advantages over mono-materials in terms of weight, damping, and mechanical property tuning. With this in mind, this review focuses on the various aspects of MPM SMs (Metal/polymer/metal Sandwich Materials). The reasons for the improved qualities of MPM SMs have been discussed, as well as the numerous approaches to producing such SMs. This review shows the various possibilities of achieving such SMs in complicated forms via different shaping techniques and intends to highlight the properties of MPM SMs’ remarkable qualities, the current trend in this field, and their potential to meet the demands of many industries.

The study examines the impact of microstructure and polymethyl methacrylate (PMMA) grafting on the degradability of Zn-Mg alloys. The mechanical properties of a Zn alloy containing 0.68 wt% Mg and extruded at 200 °C are enhanced for degradable load-bearing applications, addressing a crucial need in the field. The material exhibits a bimodal grain size distribution that is random texture, consisting of secondary phases, grains, and sub-grains. With an elongation to failure of 16 %, the yield and ultimate tensile strengths are 325.9 and 414.5 MPa, respectively, and the compressive yield strength is 450.5 MPa. The "grafting-from" method was used to coat a few micrometers thick of PMMA on both bulk and scaffold Zn alloys to mitigate the corrosion rate. The last one is a porous structure, with a porosity of 65.8 %, considered as in the first approach of an orthopedic implant. After being immersed for 720 h, the PMMA-grafted bulk alloy's corrosion rate decreased from 0.43 to 0.25 mm/y. Similarly, the scaffold alloy's corrosion rate reduced from 1.24 to 0.49 mm/y. These results indicate that the method employed could be used for future orthopedic applications.

Surface-initiated atom transfer radical polymerization created hybrid Ti sheet systems grafted with the poly(methyl methacrylate) (PMMA) family for biomedical application. This metal/polymer hybrid material exhibits strong bonding at the interface. While the first research concentrated on PMMA on millimeter-sized Ti samples, the technique was expanded to large-sized (100 × 200mm²) using methyl methacrylate (MMA) and also a blend of MMA and butyl methacrylate instead of the MMA during the polymerization step.

This paper focuses on investigating the forming behaviour of sandwich materials composed of steel sheets and glass fibre-reinforced polyamide 6 (GF-PA6), i.e., thermoplastic-based fibre metal laminates (FML). Stretching and forming limit curve (FLC) determination of FML with different cover/core layer thickness ratios at various forming temperatures, i.e., at room temperature (RT), 200 and 235 °C, are the main approaches for characterizing their formability. In addition, the formability of mono-materials and non-reinforced sandwich materials is investigated as a reference. For a successful test and reliable results, several technical issues are considered, such as the suitable lubrication configuration and digital image correlation at elevated forming temperatures. The results revealed that the formability of non-reinforced sandwich materials with different core layer thicknesses exhibited compared formability to their monolithic steel sheet and no remarkable improvement in their formability with increasing the temperature up to 200 °C. Conversely, the formability of FML shows significant improvement (approx. 300%) with increasing temperature with a forming depth of about 33 mm at 235 °C compared to only 12 mm at RT.

Biocompatible polymers such as polymethyl methacrylate (PMMA), despite fulfilling biomedical aspects, lack the mechanical strength needed for hard-tissue implant applications. This gap can be closed by using composites with metallic reinforcements, as their adaptable mechanical properties can overcome this problem. Keeping this in mind, novel Ti-mesh-reinforced PMMA composites were developed. The influence of the orientation and volume fraction of the mesh on the mechanical properties of the composites was investigated. The composites were prepared by adding Ti meshes between PMMA layers, cured by hot-pressing above the glass transition temperature of PMMA, where the interdiffusion of PMMA through the spaces in the Ti mesh provided sufficient mechanical clamping and adhesion between the layers. The increase in the volume fraction of Ti led to a tremendous improvement in the mechanical properties of the composites. A significant anisotropic behaviour was analysed depending on the direction of the mesh. Furthermore, the shaping possibilities of these composites were investigated via four-point bending tests. High shaping possibility was found for these composites when they were shaped at elevated temperature. These promising results show the potential of these materials to be used for patient-specific implant applications.

The thorough characterization of polymer chains grafted through a “grafting-from” process onto substrates based on the determination of number (Mn) and weight (Mw) average molar masses, as well as dispersity (Ɖ), is quite challenging. It requires the cleavage of grafted chains selectively at the polymer–substrate bond without polymer degradation to allow their analysis in solution with steric exclusion chromatography, in particular. The study herein describes a technique for the selective cleavage of PMMA grafted onto titanium substrate (Ti-PMMA) using an anchoring molecule that combines an atom transfer radical polymerization (ATRP) initiator and a UV-cleavable moiety. This technique allows the demonstration of the efficiency of the ATRP of PMMA on titanium substrates and verification that the chains were grown homogeneously.

Although zinc (Zn) is one of the elements with the greatest potential for biodegradable uses, pure Zn does not have the ideal mechanical or degrading properties for orthopaedic applications. The current research aims at studying the microstructure and corrosion behaviour of pure Zn (used as a reference material) and Zn alloyed with 1.89 wt.% magnesium (Mg), both in their extruded states as well as after being coated with polymethyl methacrylate (PMMA). The grafting-from approach was used to create a PMMA covering. The “grafting-from” method entails three steps: the alkali activation of the alloys, their functionalization with an initiator of polymerization through a phosphonate-attaching group, and the surface-initiated atom transfer radical polymerisation (SI-ATRP) to grow PMMA chains. Electrochemical and immersion corrosion tests were carried out in a simulated body fluid (SBF), and both confirmed the enhanced corrosion behaviour obtained after coating. The electrochemical test revealed a decrease in the degradation rate of the alloy from 0.37 ± 0.14 mm/y to 0.22 ± 0.01 mm/y. The immersion test showed the ability of complete protection for 240 h. After 720 h of immersion, the coated alloy displays minute crevice corrosion with very trivial pitting compared to the severe localized (galvanic and pitting) corrosion type that was detected in the bare alloy.

The newly-developed thermoplastic-based fibre metal laminates (T-FML) show good prospects for their application in the automotive industry because of their lightweight potential and thermal formability. This paper focuses on describing the tensile and bending properties of this hybrid material as structural components for load-bearing parts in vehicles. For this purpose, the uniaxial tensile and four-point bending behaviours of steel/glass fibre-reinforced polyamide 6 (GF-PA6)/steel-laminates are investigated. The effects of cover/core layer thickness ratio and fibre weaving style on their tensile and bending properties are considered, while the span-to-thickness ratio was kept constant. Testing of the mono-materials and laminates of Metal/PA6/Metal (MPM) is performed to be considered as a reference. Further, the analytical method is validated to predict the bending properties of the laminates. A good agreement between the analytical values and experimental results regarding the bending strength and modulus is revealed. T-FML showed better tensile and bending properties with increasing fibre content compared to the GF-PA6 mono-organosheet and MPM.

Mass flow inequality in the initial stage of tube processing can lead to eccentricity and micro- and nano-structural changes that affect residual stress and texture development. In this study, the macro- and micro-texture development of copper tubes drawn with a tilted die was investigated using three methods: synchrotron, neutron diffraction, and electron backscatter diffraction, in the positions of maximum and minimum wall thickness of the tubes. Understanding how a tilted die can affect the texture development in copper tubes is the main aim of this study. The micro-texture results of EBSD examinations showed the same behavior at the maximum and minimum sides of the as-received tube, as observed using the synchrotron diffraction method as well as macro-texture measurements. The cube texture component was found to be the predominant orientation in the as-received tube. However, it almost disappeared after drawing with −5° tilting. By contrast, the Cu texture component increased significantly. Before drawing, the cube component varied strongly across the wall thickness. After drawing, however, there was no noticeable texture gradient across the wall thickness. The analyses showed that tilting is not creating an inhomogeneous texture development over the circumference.

Cold tube drawing is a metal-forming process. It involves drawing tubes through a conical die with or without an inner tool to change the diameter and/or wall thickness. Despite the fact that the drawing process has been well studied analytically, improving productivity and product quality is still a major factor for the tube industry. Eccentricity, as an important parameter for producing high-precision tubes, can be influenced by appropriately tilting the die. This has been proven both with and without a fixed plug before. The effect of using a floating plug in combination with tilting on eccentricity was investigated, as well as the residual stresses in the tubes. In addition, the plug geometry has been investigated and optimized using finite element method to increase the possible tilting angle to 3°. Floating plugs regulate eccentricity similarly to fixed plugs. Under the given conditions, residual stresses do not exhibit a high level and dominant change, but rather are shifted towards the compressive direction. The formation of curves is caused by an uneven load distribution and material flow over the circumference of the tube caused by tilting the die. With a guiding die placed in front of the forming die, curve formation could be markedly reduced with only a small loss in the eccentricity effect.

A metal/polymer/metal sandwich can combine the benefits of individual materials with desirable properties and functionalities. They are commonly used in aviation and automotive industries. They provide the desired mechanical strength, high elasticity, and light weight, which also makes them suitable for biomedical prostheses by bridging the gap between implants and human tissues. However, epoxy resins, generally used for bonding the individual layers in industrial applications, are detrimental to biomedical applications. Therefore, it is essential to replace epoxy resins with a biocompatible interlayer to ensure both biocompatibility and faultless adhesion by a strong covalent bond. The interest in this material configuration has surged since the early work by Palkowski in this field. This study offers an encompassing view of metal/polymer/metal sandwich systems and delves into a comprehensive discussion about their diverse applications.

The craniomaxillofacial region contains several bones and serves to protect and support the area from the brain to the masticatory system. In this paper, the clinical and research aspects of craniomaxillofacial biomaterials are highlighted to serve as a guide into the wide world of their reconstructions. After a quick look into the anatomy, this review focuses on the causes of large bone defects in this region and how they influence the designing process of the implant. Since it is a large area to unfold, only the maxillary, the mandible and the temporomandibular joints are highlighted. Understanding the biomechanics of mandible and temporomandibular joints is quite important, as it strongly influences the choice of the biomaterial. Thus, the latest techniques implemented to understand the biomechanics of the mandible are also highlighted. By way of the finite-element analysis, a simulation can help identify the forces and the movements of the mandible and predict the possible outcome of the implantation influencing the choice of the biomaterial.

The modification of the surface of pure titanium (Ti) implant by grafting biomimetic polymer offers the possibility of camouflaging the synthetic origin of the implant to bone cells. In our previous studies, we have shown that with ultraviolet irradiation (UV) technology, polymers such as poly(methyl methacrylate) (PMMA) and poly(sodium styrene sulfonate) (PNaSS) can be selectively grafted onto Ti surfaces. This technology offers the possibility to photochemically modify Ti-PMMA grafted surfaces by UV light with the formation of carboxylic acid groups that will allow the grafting of PNaSS. A biological study of functionalized Ti-PMMA-PNaSS surfaces in contact with bone cells was performed along with the physicochemical characterizations of the functionalization. The Fourier-transformed infrared spectra recorded in an attenuated total reflection (FTIR-ATR) results confirmed that carboxylic acid sites (-OH, -CO, -COOH) were incorporated into the surface during UV light exposure. Moreover, the morphological images obtained with environmental scanning electron microscopy (SEM), the differentiation and mineralization results showed an improvement of osteoblast cells spreading on Ti-PMMA-PNaSS grafted surfaces.

Anisotropic behavior is a key characteristic for understanding eccentricity in tubes. In this paper, the effect of using a tilted die during tube drawing on eccentricity, texture, dislocation density, and mechanical properties is shown. Copper tubes were drawn with a ±5° tilted die for two passes. The increase or decrease in eccentricity can be controlled by controlling the angle of the tilted die. Two types of textures have been developed during tube drawing, namely plane strain and uniaxial types. Plain strain type texture is mainly characterized by the β fiber with a dominant copper component {112}<111>. The uniaxial deformation type is dominated by the <111> fiber, as commonly found by wire drawing. Texture sharpness increases with increasing drawing strain, and the texture varies significantly between the maximum and minimum wall thickness. This texture variation between maximum and minimum wall thickness has no significant influence on mechanical properties, which are more or less similar, but the increase in strength after each drawing pass is apparent. The dislocation density is low for the as-received tubes due to recovery and recrystallization. This is consistent with the as-received texture dominated by the cube component {001}<100>. During tube drawing, dislocation density increases as a function of the deformation strain. The variation of dislocation density between the maximum and minimum wall thickness in the tube deformed with −5° tilted die is higher than the variation in the tube deformed with +5° tilted die.

The world of biomaterials has been continuously evolving. Where in the past only mono-material implants were used, the growth in technology and collaboration between researchers from different sectors has led to a tremendous improvement in implant industry. Nowadays, composite materials are one of the leading research areas for biomedical applications. When we look toward hard tissue applications, metal-based composites seem to be desirable candidates. Metals provide the mechanical and physical properties needed for load-bearing applications, which when merged with beneficial properties of bioceramics/polymers can help in the creation of remarkable bioactive as well biodegradable implants. Keeping this in mind, this review will focus on various production routes of metal-based composite materials for hard tissue applications. Where possible, the pros and cons of the techniques have been provided.

Titanium (Ti) is the most commonly used material for cranial prostheses. However, this material does not exhibit the same mechanical properties as the bone. Incorporating polymers onto Ti by combining both their properties is a solution to overcome this issue. Thus, sandwich materials made of two Ti skin sheets and a poly(methyl methacrylate) (PMMA) core are promising structures to design biomedical prostheses. The "grafting to" and "grafting from" procedures to functionalize the Ti/PMMA interface are described in this article as two strategies for chemically connecting PMMA chains on Ti surfaces. The advantage of the first approach is the capacity to control the architecture of the grafted PMMA on Ti. Moreover, a method for selectively grafting a bioactive polymer such as poly(sodium styrene sulfonate) (PNaSS) on one side of the Ti and PMMA on the other side is developed. This contribution presents efficient ways of functionalizing Ti for biomedical applications.

The “stress-shielding” problem, common with metallic implants, may be solved by using biocompatible sandwiches with a polymeric core between two metallic skin sheets. To achieve such sandwiches, a process route has been developed, beginning with the grafting of poly-(methyl-methacrylate) (PMMA) on titanium (Ti) sheets via the “grafting from” technique. Grafting resulted in variable thicknesses of PMMA on the Ti sheets. Hot-pressing was used to prepare semi-finished Ti–PMMA–Ti sandwiches. The adhesion was achieved by the interpenetration between PMMA sheet and the grafted PMMA chains. Investigation was carried out to understand the influence of the grafted PMMA thickness on the adhesion strength. Similar adhesion strengths were found for the sandwiches despite variable grafted PMMA thicknesses, indicating a successful grafting of PMMA on large-scale Ti sheets. The adhesion followed the autohesion theory, where a time-dependent increase in adhesion strength was found for the sandwiches.