## 1 Introduction  
Ti-6 Al-4V is one of the most important and widely used titanium alloys, exhibiting specific mechanical properties, good biocompatibility, and outstanding corrosion resistance. It has been applied in the aerospace, biomechanical, and electronic industries [1]. Most Ti-6 Al-4V components are fabricated by conventional techniques involving a significant amount of machining, such as turning, end milling, drilling, reaming, tapping, sawing, and grinding, accompanied by a high loss of raw materials [2; 3]. However, high chemical reactivity, low thermal conductivity, high strength, and low elastic modulus result in the poor machinability of Ti-6 Al-4V alloy [4]. Hence, the poor machinability and high manufacturing cost for complex shaped components limit its further applications. To solve these problems, the metal injection molding (MIM) process of Ti-6 Al-4V is becoming more and more attractive in both research and industry [5; 6; 7]. MIM is a near-net-shape process that combines the merits of powder metallurgy and plastic injection molding and offers freedom in structure design [8]. The technique provides a unique opportunity for the mass production of microstructurally uniform and high-performance Ti-6 Al-4V components with complex shapes.  
In order to successfully obtain Ti-6 Al-4V components with balanced mechanical properties by MIM, sophisticated processing, including powder handling, binder system design, debinding, sintering, and post-processing technologies, is considered carefully [9; 10; 11]. Generally, prealloyedTi-6 Al-4V powder with spherical particle shape and low impurity levels is preferred because of its good moldability and low initial oxygen content. Most research works on MIM of Ti-6 Al-4V alloy have been designed starting from prealloyed powder, such as the processing optimization and improvement of mechanical properties [13; 14; 15; 16; 17]. In addition, Ti-6 Al-4V components have been successfully manufactured for industrial as well as medical applications by the MIM process from prealloyed powder [8; 18].  
Nevertheless, the high cost of fine prealloyed Ti-6 Al-4V powder limits its applications in the high-end market, becoming a barrier to wide utilization. The recycling of machine turnings by the hydrogenation-dehydrogenation (HDH) method to produce low-cost Ti-6 Al-4V powders has been tried in previous literature [19; 20]. Furthermore, some attempts have been reported using blended plasma-atomized Ti and 60 Al40V powder [21], blended TiH\({}_{2}\) and 60 Al40V powder [22], and blended gas-atomized (GA) Ti-6 Al-4V and HDH Ti-6 Al-4V powder [12] to fabricate Ti-6 Al-4V alloy by MIM to reduce the cost. However, there are almost no successful business cases reported by these reduced-cost fabrication methods. In our previous study, we demonstrated a Ti-6 Al-4V part manufactured by MIM for industrial applications at a reduced cost by using blended GA Ti and 60 Al40V powder [23]. Although the using of blended powder is a cost-effective way for mass production of MIMed Ti-6 Al-4V components, the homogeneity of the microstructure, the stability of impurity composition and mechanical properties, and the tolerance control of MIMed products remain to be further investigated, especially for the parts with complex shapes.  
In this study, Ti-6 Al-4V alloy is fabricated by MIM using blended and prealloyed powders. The effects of MIM processing details and sintering parameters on the final mechanical properties and microstructures are studied. Finally, a Ti-6 Al-4V part manufactured from blended powder is demonstrated, showing the possibility of industrial application of the cost-reducing process.