Influence of Heat Treatment Temperature on Microstructure, Hardness and Sensitization of UNS S32205 Duplex Stainless Steel.

Improper thermal cycles on duplex stainless steels can lead to the formation of detrimental phases or alter the proportion of ferrite and austenite phases, thus influencing the material's mechanical properties and corrosion resistance. Therefore, this study aimed to evaluate the effect of aging (at 850 and 950 °C) and solubilization (at 1000 and 1150 °C) thermal treatments on microstructure, indentation hardness, elasticity modulus, and susceptibility to intergranular corrosion of UNS S32205 duplex stainless steel. The sigma phase (σ) formation in the aged samples, with hardness values between 8 and 10 GPa, was confirmed.

The Corrosive Effects of Aftermarket Oil Additives on High-Leaded Tin Bronze Alloy.

Aftermarket additives are used to enhance the performance of internal combustion engines in specific aspects such as reducing wear, increasing power, and improving fuel economy. Despite their advantages, they can sometimes cause corrosion-related problems. This research evaluated the corrosiveness of four aftermarket additives on the corrosion of a high-leaded tin bronze alloy over 28 days at 80 °C in immersion tests.

Von Mises stresses on Mushroom-loop archwires for incisor retraction: a numerical study.

Objective: To perform a numerical simulation using FEM to study the von Mises stresses on Mushroom archwires.

Methods: Mushroom archwires made of titanium-molybdenum alloy with 0.017 x 0.

Fixation of the Anterior Ligament Graft at the Tibial Pole: Biomechanical Analysis of Three Methods.

 Comparative biomechanical analysis of tibial fixation strength for ligament reconstruction with interference screw compared with screw post and washer, and compared with the associated fixation of both methods (hybrid fixation).  A total of 54 specimens were used (porcine tibias and bovine flexor digital tendons), which were divided into three groups with fixation types similar to those used in anterior cruciate ligament (ACL) reconstruction: 1) fixation with interference screw; 2) fixation with screw post and toothed washer over knot and suture strand; and )- fixation with screw post and washer combined with interference screw (hybrid fixation). The analyses were performed through pull-out biomechanical tensile tests to determine the stiffness and load to system failure (yield load).

Biomechanical analysis on transverse tibial fixation in anterior cruciate ligament reconstructions.

Objective: To verify whether the combination of tibial cross pin fixation and femoral screw fixation presents biomechanical advantages when compared to femoral cross pin fixation and tibial screw fixation for the reconstruction of the anterior cruciate ligament (ACL).

Methods: Thirty-eight porcine knees and bovine extensor digitorum tendons were used as the graft materials. The tests were performed in three groups: (1) standard, used fourteen knees, and the grafts were fixated with the combination of femoral cross pin and a tibial screw; (2) inverted, used fourteen knees with an inverted combination of tibial cross pin and a femoral screw; (3) control, ten control tests performed with intact ACL.

BIOMECHANICAL STUDY OF TRANSCORTICAL OR TRANSTRABECULAR BONE FIXATION OF PATELLAR TENDON GRAFT WITH BIOABSORBABLE PINS IN ACL RECONSTRUCTION IN SHEEP.

Objective: To determine the initial resistance of fixation using the Rigid Fix(®) system, and compare it with traditional fixation methods using metal interference screws; and to evaluate the resistance of the fixation with the rigid fix system when the rotational position of the bone block is altered in the interior of the femoral tunnel.

Methods: forty ovine knee specimens (stifle joints) were submitted to anterior cruciate ligament reconstruction (ACL) using a bone-tendon-bone graft. In twenty specimens, the Rigid Fix method was used; this group was subdivided into two groups: ten knees the pins transfixed only the spongious area of the bone block, and ten for fixation passing through the layer of cortical bone.

[Biomechanic analysis of the sewed tendons for the reconstruction of the anterior cruciate ligament].

Objective: To evaluate the difference of the mechanical behavior of bended tied (sewed) and not tied hamstring tendons in order to evaluate if it has any effective function.

Methods: Twenty-four fresh bovine digital tendons had been used. Alginate to determine the area of the tendon transversal section was used.

Alternative methodology for flexural strength testing in natural teeth.

The use of natural teeth for performing in vivo , in situ and/or in vitro studies has been widely observed in the dental field. The mechanical behavior of teeth subjected to masticatory efforts is commonly used as a variable of response. In conditions of malocclusion, the most relevant component accounting for the integrity of the dental structure is non-axial (flexural).

Experimental force definition system for a new orthodontic retraction spring.

A new geometry of orthodontic retraction spring was experimentally studied through an electronic device (platform for measuring forces), using strain gauges that were adapted to cantilever beams. The sample consisted of 36 titanium-molybdenum springs, divided into three groups of 12 springs each. The springs were produced with different cross sections of 0.