Cracked and un-cracked Brazilian disc specimens subjected to diametral compression were used for conducting fracture toughness and tensile strength experiments on a polymer concrete (PC) material. The value of mode I fracture toughness (KIc) was determined from the center- cracked Brazilian disc and the indirect tensile strength (σt) was obtained from the un-cracked Brazilian disc specimen. The...

Microstructures, tensile properties and fracture energy of a friction stir spot welded polycarbonate (FSSW) were studied at varying rotational rates and dwelling time. The problem of common FSSW welding is the remaining of characteristic keyhole. This can act as a concentration place in mechanical tests. To order solve this problem authors took advantage of innovation for designing the welding ...

An ultrafine grained dual phase (UFG DP) steel containing niobium was produced by a new route utilizing simple cold-rolling and subsequent intercritical annealing of ferrite/martensite duplex starting structures. The effects of intercritical holding time on the microstructural evolutions and mechanical properties were studied. The results showed that increasing intercritical holding time enhnac...

Friction stir processing (FSP) 2519-T87 aluminum plate results in enhanced ductility, 25% strain at fracture. However, the yield strength in the FSP zone drops to 175 MPa from �400 MPa. Actively cooling the plate during FSP increases the yield strength to 185 MPa and decreases ductility to 20% strain at fracture. Thick bending of a plate of the alloy was demonstrated after the surface was subje...

Objective: This study aimed at evaluating the design and dimensions of five different brands of orthodontic mini-implants, as well as their influence on torsional fracture strength. Methods: Fifty mini-implants were divided into five groups corresponding to different manufactures (DEN, RMO, CON, NEO, SIN). Twenty-five mini-implants were subjected to fracture test by torsion in the neck and t...

Fracture strength of monolithic and bilayered LAVA and e. max lower molar crowns after load cycling was measured and compared. The study included three groups (n = 8) from LAVA zirconia and three groups from e. max lithium disilicate to compare influences of different layers, thicknesses and manufacturing techniques. Prefabricated anatomically designed crowns were cemented to dies made from Z 1...