レーザ積層造形法によるβ型Ti-15Mo-5Zr-3Al合金の集合組織形成

Abstract

Selective laser melting (SLM), a kind of additive manufacturing (AM) technologies, enables to fabricate highly complicated 3-dimensional structures from a powdered metallic materials. Recent investigations demonstrated the ability of SLM to form crystallographically texturized parts. Highly texturized materials exhibit anisotropic functions; therefore, control of texture via AM is becoming attractive strategy for developing functionalized materials. In the present study, we tried to find laser conditions for formation of randomly and highly texturized parts in SLM of T-15Mo-5Zr-3Al biomedical alloy. We successfully achieved randomly and highly texturized parts under the conditions of (low laser power and low scan speed) and (high laser power and high scan speed), respectively. The highly texturized part showed anisotropy in Young's modulus in which the value in <001> oriented direction was significantly lower than that in <011> oriented direction, the similar trend to those reported in single crystal of this alloy. The evolution of crystallographic texture was thought to be related with melt-pool shape, which needs further investigations.

Review — Microstructural Control and Functional Enhancement of Light Metal Materials via Metal Additive Manufacturing

“…Such a melt pool is realized by scanning the heat source at a low speed. Figure 7(a)(e) shows the IPF map of the Ti15Mo5Zr3Al alloy, demonstrating the changes in its texture when the scanning speed is varied at a fixed energy density; 15,43) the scanning speed increases from panels a to e. It is clear from the IPF map, pole figure (Fig. 7(a)(e)), and A d v a n c e V i e w degree of crystal orientation in each direction (Fig.…”

Control of Anisotropic Crystallographic Texture in Powder Bed Fusion Additive Manufacturing of Metals and Ceramics—A Review

“…Ishimoto et al previously investigated this phenomenon in a bcc-structured Ti-15Mo-5Zr-3Al (wt.%) alloy for application as an implant material. 27,[59][60][61] Herein, more precise results are presented. Five different Ti-15Mo-5Zr-3Al specimens were fabricated via L-PBF with a fixed E-value of 50 J/mm 3 while P and v were varied systematically (Table I).…”

“…To clarify the physical origin of such texture variations, microstructural observations were conducted. 59 Figure 3a and b shows SEM images of the building z-surface of samples fabricated at the lowest (condition 1) and highest scanning speed (condition 5). The difference in scanning speed affected the morphology of the melt pool.…”