As a crucial branch for titanium industry, high-strength titanium alloys (HS-TAs, with UTS ≥ 1100 MPa) are indispensable structural materials for advanced engineering applications such as aerospace and marine fields. Along with the expansion of HS-TAs’ market, achieving satisfying synergies of high strength, high ductility (elongation ≥ 6%) and high toughness (KIC ≥ 50 MPa⋅m1/2) has been identified as the uppermost technical bottleneck for their research and development. To overcome the challenge, two primary strategies have been initiated by the titanium community, developing novel alloys and innovating processing technologies. For the former, a dozen of newly-developed alloys were reported to exhibit excellent strength-ductility-toughness combinations, including Ti-5553, BT22, TC21 and Ti-1300, for which the ideal mechanical performances were based on specific microstructures realized by low impurity rate (e.g. oxygen content ≤ 0.15 wt%), complicated processing and complex heat treatment. For the latter, several innovatory forging and heat treatment technologies were originated for the mature alloys to optimize their balanced property by extraordinary microstructural characteristics. In this review, we provide a comprehensive overview over the research status, processing and heat treatment technologies, phase transformation, processing-microstructure-property correlation and strengthening-toughening mechanism of HS-TAs for aerospace engineering applications manufactured via melting-forging process. Finally, the prospects and recommendations for further investigation and development are proposed based on this review. 

High-strength titanium alloys for aerospace engineering applications: A review on melting-forging process

Discoveries made by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo have ushered in the era of gravitational-wave astronomy. Upgrades in instrumentation and technology over the next ﬁve to ten years will enable these detectors to explore sources with higher ﬁdelity with the potential to make phenomenal new discoveries. To realize its full potential gravitational-wave astronomy would require the construction of new facilities that can host increasingly improved instrumentation for a period of ∼ 50 years. In this paper, we use simple performance metrics to assess the science capabilities of planned and future networks. These metrics all refer to coalescences of binary neutron stars and black holes and include: (i) network detection e ﬃ ciency and detection rate of cosmological sources and their number densities as a function of redshift, (ii) signal-to-noise ratios and the accuracy with which intrinsic and extrinsic parameters would be measured, and (iii) enabling multimessenger astronomy with gravitational waves by accurate 3D localization and early warning alerts. We will in addition discuss the science enabled by the small population of loud and rare events. While imminent upgrades will provide impressive advances in all these metrics, future observatories of Cosmic Explorer and Einstein Telescope, currently being planned, will realize the full potential of gravitational-wave astronomy over the next two to three decades—observing coalescing compact binaries from epochs before the formation of ﬁrst stars, should they exist.

Listening to the Universe with Next Generation Ground-Based Gravitational-Wave Detectors

Ti and Ti alloys have charming comprehensive properties (high specific strength, strong corrosion resistance, and excellent biocompatibility) that make them the ideal choice in orthopedic and dental applications, especially in the particular fabrication of orthopedic and dental implants. However, these alloys present some shortcomings, specifically elastic modulus, wear, corrosion, and biological performance. Beta-titanium (β-Ti) alloys have been studied as low elastic modulus and low toxic or non-toxic elements. The present work summarizes the improvements of the properties systematically (elastic modulus, hardness, wear resistance, corrosion resistance, antibacterial property, and bone regeneration) for β-Ti alloys via surface modification to address these shortcomings. Additionally, the shortcomings and prospects of the present research are put forward. β-Ti alloys have potential regarding implants in biomedical fields.

β-Ti Alloys for Orthopedic and Dental Applications: A Review of Progress on Improvement of Properties through Surface Modification

Investigation on surface roughness and hardness of β-Ti alloy by ball burnishing assisted electrical discharge cladding for bio-medical applications

Titanium alloys are promising candidates for orthopedic implants due to their mechanical resilience and biocompatibility. Current titanium alloys in orthopedic implants still suffer from low wear and corrosion resistance. Here, we present a computational method for optimizing the composition of titanium alloys for enhanced corrosion and wear resistance without compromising on other aspects such as phase stability, biocompatibility, and strength. We use the cohesive energy, oxide formation energy, surface work function, and the elastic shear modulus of pure elements as proxy descriptors to guide us towards alloys with enhanced wear and corrosion resistance. For the best-selected candidates, we then use the CALPHAD approach, as implemented in the Thermo-Calc software, to calculate the phase diagram, yield strength, hardness, Pourbaix diagram, and the Pilling-Bedworth (PB) ratio. These calculations are used to assess the thermodynamic stability, biocompatibility, corrosion resistance, and wear resistance of the selected alloys. Additionally, we provide insights about the role of silicon on improving the corrosion and wear resistance of alloys. 

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Computational design of corrosion-resistant and wear-resistant titanium alloys for orthopedic implants

Development and heat treatment of β-phase titanium alloy for orthopedic application

The pre-merger (early-warning) gravitational-wave (GW) detection and localization of a compact binary merger would enable astronomers to capture potential electromagnetic (EM) emissions around the time of the merger, thus shedding light on the complex physics of the merger. While early detection and sky localization are of primary importance to the multimessenger follow-up of the event, improved estimates of luminosity distance and orbital inclination could also provide insights on the observability of the EM emission. In this work, we demonstrate that the inclusion of higher modes of gravitational radiation, which vibrate at higher multiples of the orbital frequency than the dominant mode, would significantly improve the earlywarning estimates of the luminosity distance and orbital inclination of the binary. This will help astronomers to better determine their follow-up strategy. Focusing on future observing runs of the ground-based GW detector network [O5 run of LIGOVirgo-KAGRA, Voyager, and third-generation (3G) detectors], we show that for a range of masses spanning the neutron-star black-hole binaries that are potentially EM-bright, the inclusion of higher modes improve the luminosity distance estimates by a factor of ∼ 1 − 1.5 (1.1 − 2) [1.1 − 5] for the O5 (Voyager) [3G] observing scenario, 45 (45) [300] seconds before the merger for the sources located at 100 Mpc. There are significant improvements in orbital inclination estimates as well. We also investigate these improvements with varying sky-location and polarization angle. Combining the luminosity distance uncertainties with localization skyarea estimates, we find that the number of galaxies within localization volume is reduced by a factor of ∼ 1− 2.5 (1.2− 4) [1.2− 10] with the inclusion of higher modes at early-warning time of 45 (45) [300] seconds in O5 (Voyager) [3G].

/pdf/improved-early-warning-estimates-of-luminosity-distance-and-217ri3jo.pdf

Improved early-warning estimates of luminosity distance and orbital inclination of compact binary mergers using higher modes of gravitational radiation

Muna Kumar Singh

Papers

Development and heat treatment of β-phase titanium alloy for orthopedic application

Improved early-warning estimates of luminosity distance and orbital inclination of compact binary mergers using higher modes of gravitational radiation