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Introduction: The purpose of this study was to ascertain the primary ex vivo biomechanical stability of a novel bioabsorbable magnesium alloy (ZX00: Mg–Zn–Ca) bone anchor in human cadaveric proximal humeri, indicated in the reconstruction of the rotator cuff.

Methods: Twenty human Thiel-embalmed cadaveric humeri were prepared and freed from soft tissue. One $\varnothing$5.7 × 20.5-mm ZX00 anchor and one $\varnothing$5.5 mm × 16.3 mm Arthrex Titanium FT Corkscrew (ATC) control anchor were inserted into the footprint of the supraspinatus tendon, 15 mm apart. The humeri were mounted onto a material testing machine and following a 40 N preload, cyclic loading was performed over 400 cycles. If the construct remained intact, ultimate load to failure (ULTF) was measured using an increasing axial load of 1 mm/s, ULTF and mode of failure were recorded.

Results: No difference was found in the ability to withstand cyclic loading, mode or load-to-failure strengths between ZX00 and control anchors. The maximum tractional force loaded for the ZX00 anchors had a median of 257.4 N (range 165.3–328.2). The corresponding value for the ATC anchors averaged 239.9 N (range 118.9–306.7).

Conclusion: ZX00 alloy anchors appear to provide adequate initial biomechanical stability when compared to an industry-standard control in a cadaveric rotator cuff repair model.

Modification of bioceramics by ion implantation of magnesium (Mg) is of interest as Mg is the fourth abundant cation in the human body. In this work, magnesium was ion-implanted into a ZrO₂ based bioceramic stabilized with Y₂O₃ and Al₂O₃. Both Mg-implanted and unimplanted samples were soaked in a simulated body fluid (SBF) for a period of time. The deposits on the surface of various samples were characterized with scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). We find that the Mg-implanted ZrO₂ shows better bioactivity than the plain bioceramic. These results indicate that Mg-implantation can improve the bioactivity of the ZrO₂ based bioceramic. Mechanisms governing the improvement are discussed in this paper.

AZ91D magnesium alloys with and without dispersed SiC particles were oxidized between 420 and 500°C in air. They oxidized to fine MgO oxide grains containing dissolved ions of Al. Their oxidation rates increased almost linearly, with an increase in the oxidation temperature and time. SiC particles did not oxidize during oxidation, and increased the oxidation resistance of the alloy through diminishing the exposed surface area. With the increase in the amount of the dispersed SiC particles from 5 to 10, and to 20 wt.%, the oxidation resistance progressively increased.

The need of engineered materials with high strength to weight ratio was instrumental for the development of a novel magnesium metal–metal composite with the addition of titanium (reinforcement) and aluminum (alloying element) through disintegrated melt deposition technique. The X-ray diffraction analysis and scanning electron microscopy analysis used to explore the metallurgical insights of the developed magnesium metal–metal composite. Wear tests were carried out with pin-on-disc equipment by varying the input parameters load and sliding velocity over a sliding distance of 2000m. Wear was obtained as the output from the experiments, and the same was analyzed through Pareto analysis of variance, to identify the significant parameters. Also, a fuzzy logic-based model was developed to predict the wear behavior of the metal–metal composite. The wear mechanisms involved in the dry sliding wear behavior were analyzed through worn surface analysis and wear debris analysis.

Magnesium is reinforced with three different weight percentages (5%, 10% and 15%) of SiC particles (200 mesh size) by stir casting technique to fabricate Mg/SiC_p composites. The Scanning Electron Microscope (SEM) images, micro and macro hardness of three different composites are investigated. The comparison of micro and macro hardness clearly shows that increase in the weight percentage of SiC contributed to increase in hardness. However, uniform dispersion of SiC can be achieved while adding 5% SiC in the composite. Then, the Box Behnken experimental design in response surface methodology is employed for machining 3mm diameter hole in the Mg/SiC_p samples using EDM. The second-order model for Material Removal Rate (MRR) and Tool Wear Rate (TWR) are developed with the influencing parameters of weight percentage of SiC, current, pulse on time and pulse off time. The parameter optimization yields maximum MRR and minimum TWR.

In this work, the dry sliding wear behaviors of pure monolithic magnesium and magnesium–titanium dioxide (Mg–TiO₂) composites were studied using pin-on-disc tribometer against an oil-hardened nonshrinking die steel (OHNS) counter-disc with a normal load of 0.5–2kg and a sliding velocity of 1.5–2.5$\mathrm{\text{m}}\cdot {\mathrm{\text{s}}}^{-1}$ with the sliding distance and wear track diameter of 1500m and 90mm, respectively. The pin samples were characterized for their microstructural, nanomechanical and tribological properties such as wear rate, coefficient of friction and wear fractographs. Scanning electron microscopy (SEM) was used to analyze the worn-out surfaces of each pin sample in order to identify the different types of wear and wear mechanisms and the chemical constituents of each element were quantified by energy-dispersive spectroscopy. The influence of TiO₂ reinforcements on the nanomechanical behavior was studied by nanoindentation technique. As compared with pure Mg, the nanoindentation strengths of Mg–1.5TiO₂, Mg–2.5TiO₂ and Mg–5TiO₂ composites were found to increase by 11.9%, 22.2% and 35.8%, respectively, which was due to the addition of TiO₂ particles and also due to the good bonding at the interface of TiO₂ and magnesium particles. From the wear test results, a significant change in wear rate was observed with the change in normal load than that of sliding speed, whereas a significant change in coefficient of friction was noticed with the changes in both normal load and sliding velocity. The dominant wear mechanisms involved under the testing conditions were identified through plotting the contour maps and SEM fractographs. Also, from the fractographs it was noticed that delamination and plowing effect have been the significant wear mechanisms observed during low wear rate of samples, whereas melting, delamination and oxidation wear have been observed during high wear rate of pure Mg and its composites.

The current scenario focuses on lightweight and better energy-absorbing structural materials for critical engineering applications in aerospace, automobiles, marine, electronic, and implant materials for biomedical industries. The magnesium-based syntactic foams are the preferred choice of material in the same category due to their lightweight, higher plateau strength, better damping characteristics, and excellent energy absorption behavior. Many works were reported based on the polymer and aluminum-based syntactic foams and their developments. However, the rapidly increasing interest in magnesium-based syntactic foams and the adoption of the applications are still at a nascent stage. This proposed review work comprehensively insights the magnesium-based syntactic foam; various hollow filler material usages and summarizes the influence of physical and mechanical behavior on processing routes and future research opportunities for applications.

Permanent metallic stents are frequently used in cardiovascular interventions, due to the many advantages metals possess in bulk and surface properties, design and chemistry, as well as their high modulus and ease of producing thin sections. However, the presence of foreign bodies in humans is associated with many long-term safety concerns; removal of the stent is therefore preferred through a second intervention after recovery. Based primarily on this consideration, biodegradable stents have been of significant interest in the past few years. This paper reports the manufacturing and near-physiological testing of a novel Biodegradable Metallic Coronary Stent (BMCS). To date, very limited literature is available on this aspect of research. Generally, magnesium is reactive and generally difficult to process. However, preliminary results demonstrate strong feasibility of fabricating low-profiled magnesium-based biodegradable coronary stents. Near-physiological tests based on a specially designed accelerated radial stent fatigue system were carried out. Results show that the biodegradable stents retained their arterial scaffolding functions for up to one year (simulated) before totally being resorbed into the biological fluid past its point of functionality. The results obtained so far show great promise for application.

Rapid tooling processes are now well known and largely implemented in the plastic injection industries. Harsh conditions related to metal casting or injection do not allow such rapid tooling processes to be directly applicable. This paper focuses on magnesium alloy casting in rapid prototyped mold with thin walls created by Direct Metal Laser Sintering. Such molds are anisotropic, due to special laser exposure between their skin and core. Hence, experimental results from casting are described and analyzed. The results can help companies improve their rapid prototyping means in the field of magnesium casting of precise parts in permanent molds.

The present study proposes a constitutive model for deformation twinning which takes into account the twin degrees of freedom via incompatibility tensor model based on Field Theory of Multiscale Plasticity (FTMP). The model is introduced in the hardening law in the FTMP-based crystalline plasticity framework, which is further implemented into a finite element code. Deformation analyses are made for pure single crystal magnesium with HCP structure, and the descriptive capabilities of the proposed model are confirmed based on critical comparisons with experimental data under plain–strain compression in multiple orientations, available in the literature. The simulated results are demonstrated to successfully reproduce the unique stress–strain responses induced by twinning. The evolution of the relative activities of the various slips, and twin mechanisms for each orientation are extensively examined.

The design and optimisation of the runner and gating systems is a key factor involved in the die casting of high quality products. Poor gating designs can lead to various defects such as gas porosity, shrinkage porosity, flow lines, cold shuts and poor surface finish. CAE techniques are considered as the most cost-effective way in optimisation of the runner and gating design. A thin-walled magnesium telecommunication part was selected to be hot chamber die cast. Both computer aided design and numerical simulation techniques were applied for the optimisation of the runner and gating. The runner and gating system for the thin-walled part was designed with the aid of CASTFLOW. "Cast shots" were then simulated on a computer using a commercial software "MAGMAsoft" to numerically analyse the mould filling pattern. Die inserts were fabricated based on the simulation results. A series of casting experiments were conducted. The short shot filling tests proved that the simulation results matched the actual casting results very well. The castings were sectioned for microstructural examinations. Good quality thin-walled telecommunication parts with sound microstructure were produced.

Magnesium die casting has grown rapidly because of its excellent mechanical, electromagnetic and thermal properties, but it is still a trail and error process to design the gating system. In this paper, a commercial software package was used to simulate the filling process of die casting of a test bar. Two different gating systems were examined. It is shown from the simulation results that the melt fills the far end first and fills the rest of the part. The last filled sections are near the gates. No major difference was found between the filling processes of the two different gating systems. Compared with the experiment data of porosity level, it is shown that the porosity distribution in the final casting has a good agreement with that guessed by filling process.

Hot end is a key part of hot chamber die casting machine. In order to improve shot control and predict the life span of hot end parts, it is important to understand the melt flow and thermal conditions of the hot end in the furnace. A simulation program "VStar_HotEnd" using Finite Difference Method (FDM) is developed. The system consists of three modules: pre-processor, main-solver and post-processor. The pre-processor provides an interface with other CAD software such as Pro-E and AUTOCAD to convert three-dimensional geometric files in STL format into FDM mesh format. Thermal data for some typical materials and boundary conditions are collected in a library. The process of simulation is carried out by the main-solver after parameters are defined by the user. During the simulation the software allows the user to stop and watch the real-time position of melt front and the temperature distribution in the furnace. The post-processor makes it possible to display the simulation results with various points of view and sections and export the screen image to a printer. An example of using VStar_HotEnd to simulate the hot end of a die casting machine is provided.

Aluminum alloys, such as the 6082 alloy, is now becoming established for future lightweight vehicle structures, while Magnesium alloys remain a specialist material. By developing a low-cost, massproduction route for sheet magnesium, designers can start to explore the use of pressed magnesium panels into future vehicles. In this work, it is presented the feasibility study for an application and development of a hot forming technology to the forming an automotive external body (skin) panel. The reported forming trials of the front cowl panel were conducted using AA6082 and AZ31b alloys.