Friction Stir Link (United States)

The broad range applications of Ultra-Fine Grained metals is substantially limited by the lack of a welding method that allows them to be joined without losing the strong refinement of structure. From this point of view, the solid state welding processes are privileged. Friction welding tests were carried out on UFG 316L stainless steel. A joining process at high temperature activates the recrystallization, therefore the friction welding parameters were selected according to the criterion of the lowest degree of weakness due to recrystallization in the heat affected zone. In order to characterize the structure of basic material and selected areas of the obtained joint, were performed SEM, TEM and metallographic examinations in terms of hardness and range of softening of the material and tensile test. Despite the short time and relatively low welding temperature, results of the test by scanning electron microscopy and transmission electron microscopy confirmed the loss of the primary ultrafine structure in the Heat Affected Zone of welded joint.

Scleral contact lens (ScCL) handling may be challenging and is the principle reason for ScCL drop out. ScCL care systems are more intricate than other lens modalities and include solutions for cleaning, disinfection, storing, rinsing and filling the lens; respecting the use of each solution recommended is fundamental. Replacement of the lenses, solutions, case and plungers are important in order to decrease the risk of adverse events associated with ScCL wear. Compliance is crucial regarding hygiene, solution use, case and plunger care, wear time, follow-up schedule, and handling techniques. Non-compliance may lead to discontinuation of ScCL due to difficulties associated with this unique lens design.
 This paper presents complications secondary to handling, care and compliance that clinicians and patients may encounter while wearing ScCL. Instructions are provided to enhance the understanding on management surrounding these issues. This manuscript includes three tables to summarize types of complications, their symptoms, clinical signs, etiology, and management for a quick find index for easy consultation during daily clinical practice.

<div class="section abstract"><div class="htmlview paragraph">Metal pickup is a phenomenon that can be observed during dynamic braking with automotive disc brakes. Hard metallic particle agglomerations embedded in the friction materials rubbing surface can lead to severe disc scoring, accelerated wear and deterioration of the friction surface of either brake disc or brake pad. Such kind of surface conditions are also suspected for generating brake squeal, even if a direct root cause effect had not been proven so far. Disc scoring effects have been reported for all kinds of applications, reaching from small passenger cars up to commercial vehicles as well as railroad brakes. Although such phenomena are known since long, they still appear causing problems in brake systems of today.</div><div class="htmlview paragraph">Some recent papers have described the effect and mentioned preferable conditions for the appearance of metal pickup. Specific procedures have been proposed for provocation of the effect to allow a better and more systematic investigation of the influencing parameters. Observations on results of such experiments were described and several working hypotheses put forward with influences going back to the brake rotors metallurgy and surface finish as well as to the friction materials ingredients.</div><div class="htmlview paragraph">This paper gives an overview to the actual situation of the research and developments about the effect of metal pickup generation. An investigation of a multitude of MPU cases from real car driving is used to cluster and structure the principal phenomena and discuss the various aspects. The discussion of the experimental results and the previous findings, lead to a new experimental set up which is proposed for further investigation and future works. This shall lead to a better way of investigating and understanding the influencing parameters within the brake system, rotor and brake lining for their effect to the phenomena.</div></div>

<div class="section abstract"/>