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The overview describes the synergy between biological sciences and cellular structures processed by additive manufacturing to elucidate the significance of cellular structured implants in eliminating stress shielding and in meeting the bio-mechanical property requirements of elastic modulus, impact resistance, and fatigue strength in conjunction with the biological functionality. The convergence of additive manufacturing, computer-aided design, and structure-property relationships is envisaged to provide the solution to the current day challenges in the biomedical arena. The traditional methods of fabrication of biomedical devices including casting and mechanical forming have limitations because of the mismatch in micro/microstructure, mechanical, and physical properties with the host site. Additive manufacturing of cellular structured alloys via electron beam melting and laser powder bed fusion has benefits of fabricating patient-specific design that is obtained from the computed tomography scan of the defect site. The discussion in the overview consists of two aspects - the first one describes the underlying reason that motivated 3D printing of implants from the perspective of minimising stress shielding together with the mechanical property requirements, where the mechanical properties of cellular structured implants depend on the cellular architecture and percentage cellular porosity. The second aspect focuses on the biological response of cellular structured devices. [ABSTRACT FROM AUTHOR]

The abnormal precipitation of Ti2Ni arising from compositional inhomogeneity leads to the formation of α-laths in powder metallurgy Ti–Ni alloys. This exacerbates the detrimental effect of eutectoid on ductility. Herein, we have developed a uniform Ni-coated Ti powder to obtain rapid compositional homogeneity during sintering process. This rectified the abnormal eutectoid reaction pathway, enabling us to obtain fully equiaxed α-Ti grains. Consequently, the equiaxed microstructure effectively counteracted the degradation in ductility caused by brittle eutectoid. [ABSTRACT FROM AUTHOR]

The hot compression in the deformation temperature range of 523-673 K and strain rates of 0.001-1 s-1 was aimed to study the hot deformation behavior, processing map, and dynamic recrystallization (DRX) to confirm an optimum hot working condition of Mg-Zn-Zr alloy. The strain-stress results by using the Gleeble-1500 simulator indicated that the flow stress decreases with increasing temperature or decreasing of strain rates, and the Medium Gaussian Kernel (correlation coefficient (R) = 0.9806, absolute relative error (AARE) = 3.28 %) has better predicting capacity. Based on the processing map and constitutive equation, the optimum hot-working condition for Mg alloys can be determined to be at hot compression temperature and strain rates in the range of 593-623 K and 0.01-0.001 s-1 with a peak value of power dissipation efficiency (PDE) which is reaching to 37 %. [ABSTRACT FROM AUTHOR]

The microstructural characteristics and low-temperature impact toughness of simulated reheat coarse grain heat affected zone (CGHAZ) of high strength medium-Mn steel were investigated based on thermal simulation. The results indicated that the impact energy of unaltered reheated CGHAZ (UA CGHAZ), supercritical reheated CGHAZ (SCR CGHAZ), intercritical reheated CGHAZ (ICR CGHAZ) and subcritical reheated CGHAZ (SR CGHAZ) at –40 °C was 38, 65, 26 and 9 J, respectively, and the microhardness was 376, 385, 400, and 329 HV, respectively, at welding heat input of 15 kJ/cm. Fine martensite lath microstructure and the high proportion of misorientation boundaries in SCR CGHAZ induced relatively higher impact toughness and microhardness. The microstructure of ICR CGHAZ had inferior uniformity and consisted of lath martensite with high dislocation density and lamellar twin martensite. Thereinto, twin martensite with higher hardness and less toughness deteriorated the ICR CGHAZ toughness. The segregation of Mn at grain boundaries reduced the adhesion between grain boundaries and led to severe embrittlement of SR CGHAZ. [ABSTRACT FROM AUTHOR]