Microstructural Characteristics and Mechanical Properties of Repaired Titanium Alloy Blade by Arc Additive Manufacturing Process

Abstract

To improve repair efficiency and achieve a high‐quality repair layer, wire and arc additive manufacturing process is used in this study to repair missing‐angle Ti‐6Al‐4V blade. The deposition layer with a mixed equiaxed β and columnar grain can be obtained by optimizing the deposition speed and single layer height. According to the characteristics of β grain, the typically repaired thin‐walled part is divided into four representative areas, including heat affected zone (HAZ), bottom layer, middle layer, and top layer. The bottom layer consists of coarsely near‐equiaxed β grains with martensite α′ and basket‐weave structure, and the columnar β grains grow perpendicularly from middle layer to top layer. The heat accumulation in HAZ continues to increase which resulted in a certain degree of cooling rate reduction, resulting in the martensite α′ decomposed to α dots and rods in HAZ near the layer band. The fine near‐equiaxed β grains (78 ± 28 μm), martensite α′ structure, and fine lamellar α structure are presented in HAZ, causing the fracture transition from the HAZ to bottom region. The characteristic of ductile rupture is observed in repaired thin‐wall, the maximum tensile strength is 991 MPa, and the elongation reaches about 10%.

Improved Wear and Corrosion Resistance of Microarc Oxidation Coatings on Ti–6Al–4V Alloy with Ultrasonic Assistance for Potential Biomedical Applications

“…[1][2][3][4][5][6][7][8] Among various Ti alloys, Ti-6Al-4V alloy, which belongs to α þ β dual-phase Ti alloys, possesses good fatigue resistance, strength, and corrosion resistance. [9][10][11][12][13] Therefore, Ti-6Al-4V alloys are applied in biological fields, especially for hard tissue replacements (such as orthopedic implants). [14][15][16] However, the disadvantages of Ti-6Al-4V alloys, including low hardness, strong biological inertness, and poor wear resistance, are also apparent, which restrict their further applications.…”

Microstructural characterization and mechanical integrity of stainless steel 316L clad layers deposited via wire arc additive manufacturing for nuclear applications

“…The x‐ray diffraction results confirmed the presence of strengthening compounds (Cr 7 C 3 and Cr 3 C 2 carbides) and intermetallic precipitates with W (Co 4 W 2 C) and these phases improved the hardness and wear performance of stellite 6 in the hard overlays [24]. Wire arc additive manufacturing was used to repair missing‐angle Ti‐6Al‐4V blades and attained comparable tensile properties than cast and wrought counterparts [25]. The influence of process variables was investigated systematically for depositing stainless steel 304L single‐pass beads to repair worn‐out parts [26].…”

Design of a Cost-Effective and Statistically Validated Test Specification with Selected Machine Elements to Evaluate the Influence of the Manufacturing Process with a Focus on Additive Manufacturing

“…They extracted tensile test samples from different regions of the blade-like geometry and showed that they have comparable mechanical tensile properties according to the material specification in an as-welded condition [14]. Liu et al used WA-DED to repair a Ti6Al4V blade and obtained mechanical tensile properties for the as-welded condition, which are in the range of other manufacturing processes [15]. Yan et al demonstrated the Laser Metal Deposition (LMD) process for a Ti6Al4V blade, where lower mechanical tensile properties than for WA-DED and the casting condition TC4 were achieved [16].…”