Analysis of the Influence of Laser Power on the Microstructure and Properties of a Titanium Alloy-Reinforced Boron Carbide Matrix Composite (Ti6Al4V-B4C)

Abstract

Titanium and its alloys are used for highly demanding applications, such as in the fabrication of some of the most critical and highly stressed civilian and military aircraft parts, chemical processing, automobile industries, nuclear power plants, food processing plants and oil refinery heat exchangers. This wide range of applications has been attributed to its excellent properties, such as low density, high specific strength, heat resistance, corrosion resistance, low temperature resistance, and excellent biocompatibility. Several suggestions have been made that the physical and mechanical properties of titanium can be improved through the integration of reinforcing compounds using the principle of metal matrix composites (MMCs), since they combine the properties of ceramics and metals to produce good shear strength, high temperature strength and elevated hardness composites [1]. Titanium carbide has been agglomerated with Ti6Al4V alloy to improve its wear properties [2]. Different coatings such as plasmasprayed Al-bronze have been applied to the surface of titanium to improve the operational life [3]. The microstructural behaviour of titanium alloy is an important aspect to be studied with the establishment of new phases [4].In contrast, laser metal deposition (LMD) is an additive manufacturing (AM) technique that serves as a recommended technique for processing titanium and its alloy, since it addresses most of the problems of the traditional manufacturing methods [5]. This AM technology is also a promising aerospace manufacturing technique due to its potential of reducing the buy-to-fly ratio and repairing high valued parts [6]. Among the various methods of coating the surface of materials, which includes chemical vapour deposition, physical vapour deposition, spraying, etc., the LMD process is believed to have a greater advantage over other methods of coating [7]. Some of the advantages of using the LMD process include the ability to produce parts directly from a 3-dimensional computer aided design (CAD) model of the part [8] with the required surface coating in one step [9]; and its ability to be used for repair of existing worn out parts that were not repairable in the past [10]. Despite the significant progress in this field, there are still some of technical challenges that need improvement, which includes material characterization and availability [11]. The adopted approach of layer-by- Analysis of the Influence of Laser Power on the Microstructure and Properties of a Titanium Alloy-Reinforced Boron CarbideMatrix Composite (Ti6Al4V-B 4 C)