Integrated Experimental Approach for Alloying of Surface Layer Ti6Al4V+B4C Metal Matrix Composites using Laser Treatment

Abstract

Surface engineering applications have brought the titanium and its alloys into the limelight in the manufacturing industries such as the aerospace, automobile, marine, chemical processing industry, nuclear power and biomedical. Despite the growths experienced in the use of this material, it is plagued with poor wear behaviour, especially when in contact with other materials during application. In this research work, the reinforcement of titanium alloy (Ti6Al4V) and boron carbide (B 4 C) ceramic powders was employed to form the Ti6Al4V+B 4 C composites. The effect of laser power on the micrograph, microhardness, surface roughness and wear has been investigated. The micrographic evaluation, the geometrical analyses and the effect of laser power on the width and height of deposit, aspect ratio and dilution rate were also evaluated. The highest aspect ratio of 5.31 and dilution rate of 63.81 % was observed in sample MB5 deposited with a laser power of 2400 W. The dry sliding friction and wear conducted using a 10 mm diameter tungsten carbide ball and a normal load of 25 N revealed that sample MB2 produced at a laser power of 1800 W has the lowest wear depth and wear width of 74.6 µm and 1080.77 µm. From the lowest COF attributed by sample MB5, it can be inferred that coefficient of friction does not determine the wear loss due to the sticking of some wear debris to the wear track during sliding action. Thus, other wearing factors are also considered for the wear loss evaluation.However, this composite can be used for the repair of the worm part of a rotating shaft and turbine blades.

Surfacing – Technologies and Layer Properties (A Review)

“…Laser surfacing is realized in three ways. The first one involves the introduction of powder material into the heated zone [30], [31], [32], [33], the second assumes the remelting of a precoat [35], [36], [37] [39] and the third uses a gaseous medium to introduce the necessary components [34]. Another possibility to produce the layer is electroless cladding (ELC) from a solution and subsequent thermal treating [40], [41], [42].…”

“…The microstructure is examined by optical (OM) [1], [9], [17], [21], [23], [27], [30], [31], [36] ], [42], [43] and electron microscopy (SEM) [1], [10], [11], [14], [21], [22], [23] , [33], [39], [46], [47]. The phase composition is determined by the X-ray diffractometer [18], [23], [27], [31], [33], [36], [39], [45], the transmission diffraction electron microscopy [18] and energy-dispersive X-ray spectroscopy [14], [22], [30], [33], [39]. The X-ray fluorescence method [7] and the atomic emission spectrometer [7] were used to determine the chemical composition.…”

“…In the publications reviewed, the materials used as substrates can be divided into the following main groups: carbon steels [3], [6], [7], [12], [13], [15], [16] 17, 18, 21, 25, 26, 29, 36 and 37; alloyed steels [1], [4], [8], [9], [20], [22], [24], [30], [41] and [42]; highly alloyed steels [5] and [32]; aluminium and aluminium alloys [11], [28], [39], [43], [44] and [45]; titanium and titanium alloys [23], [31], [34] and [35]; ductile cast iron [33] and [40]. The SAS, MIG / MAG, TIG, PST, EBS and LS methods were used to apply the layers to carbon steels.…”

“…The wear resistance of the layer is about 10 times higher than that of the substrate. On the same type of substrate (Ti 6 Al 4 V) using a mixture of Ti 6 Al 4 V and B 4 C is applied a layer by direct feeding of the powder material to the melting zone [31]. The hardness achieved in this case is 480 HV.…”