Joining dental biomaterials of Ti-6Al-4V alloy and cp-Ti using transient liquid phase bonding: Metallurgical and mechanical assessment

The choice of manufacturing process plays a vital role in producing a medical device with a few problems; one of the best manufacturing processes for achieving superior physical and mechanical properties is transient liquid phase (TLP) bonding. The effect of bonding time in the range of 5-45 min on the microstructural and mechanical characterizations of the joint by an ultra-thin Cu interlayer with a thickness of 10 mu m was investigated. The results revealed that the dominant phase is Ti2Cu intermetallic compound (IMCs) in the joint zone in all samples. It was shown that intensive metallurgical reactions happened at the interface of cp-Ti/Cu/Ti-6Al-4V, and the joint zone involves Ti2Cu IMCs. By increasing the holding time, Ti2Cu is decomposed, and finally, the joint consists of tiny Ti2Cu in alpha-Ti matrix. Shear tests indicated that the homogenized joint bonded at a prolonged time exhibits better mechanical properties than those at a prolonged low time. The minimum and maximum shear strength were achieved in the quantity of 175 and 384 MPa at 5 and 45 min, respectively. The hardest zone in the samples of 5 and 45 min was the reaction zone and the diffusion-affected zone (DAZ) of Ti-6Al-4V, respectively. By the increase in the holding time, the failure mode changed from cleavage to semi-cleavage, and the fracture path was altered from the reaction zone to the DAZ of Ti-6Al-4V zone, originating from the reduction of IMCs in the joint center.

Automated summary

The choice of manufacturing process is crucial for producing flawless medical devices, and transient liquid phase (TLP) bonding is one of the best processes for achieving superior physical and mechanical properties. This study investigated the effect of bonding time on the microstructural and mechanical characteristics of joints using an ultra-thin Cu interlayer. The results showed that increasing the holding time improved the mechanical properties of the joint and changed the failure mode and fracture path.