Single-crystal diamond is a highly costly material, generally priced at approximately four times that of PCD. Inexpensive PCD tools possess exceptional properties such as ultra-hardness (8000 HV≈78.4 GPa), high wear resistance, and excellent thermal conductivity (560·W/m·K) [245], making it an ideal tool material for machining difficult-to-cut materials. PCD is a composite material made by mixing selected micron-sized diamond crystals with a small amount of metal powder (Co), and subsequently sintering it at high temperature (1400 °C) and high pressure (6 Gpa). Owing to the limited toughness of PCD, the majority of industrial PCD tools employ cemented carbide as their substrate. PCD tool incorporate Co and other metal binders, which enhances their fracture toughness. However, Co has a detrimental effect on the hardness of PCD itself. In addition, Co accelerates the conversion of diamond to graphite at high temperatures. Hence, PCD tools are well-suited for semi-finishing machining and tool requirements with high fracture toughness.
Numerous literature proved that the machinability of Titanium and titanium alloys has been extensively investigated for the past decade [246], [247], [248], [249]. It has been found that the wear resistance and high thermal conductivity of PCD enable longer life of PCD tools during machining titanium alloys. Currently, researchers discovered that enhancing the cutting performance of the PCD tool can be achieved by creating micro-nano-textured structures on the tool surface. These alterations in surface texture lead to modifications in cutting fluid pressure, enhanced cutting fluid efficacy, and desirable frictional properties between the workpiece and the tool. As a result, an improvement in both tool life and machining quality