• Journal of Advanced Marine Engineering and Technology
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• v.30 no.1
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• pp.30-41
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• 2006

This paper shows mechanical Properties and behaviors of macrostructures for specimens welded by F.S.W according to welding conditions and tool dimensions with $6.35mm_t$ aluminum 7075-T651 alloy plate. It apparently results in defect-free weld zone in case transition speed was changed to 15mm/min 61mm/min and 124mm/min under conditions of tool rotation speed such as 800rpm. 1250rpm and 1600rpm respectively with tool's Pin diameter 40mm and 60mm. The optimum mechanical property, ultimate stress,${\sigma}_Y=470Mpa$ is obtained at the condition of 124mm/min of travel speed with 800rpm of tool rotation speed using full screw type pin. shoulder dia. $20{\phi}mm$ pin dia. $6{\phi}mm$ and pin length 6mm. The full-screw type and the half-screw type pin shows the similar behaviors of weldability. It is found that the size of nugget is depended on tool transition speed and tool dimension by macrostructures of the cross section of weld zone.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.348-358
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• 2005

This paper showed mechanical properties and behaviors of macrostructures for specimens welded by F.S.W according to welding conditions and tool with 6.35$mm_t$ aluminum 7075-T651alloy plate. It resulted in defect-free weld zone in case tool rotation speed was 800rpm, 1250rpm and 1600rpm respectively that transition speed was changed to 15mm/min, 61mm/min and 124mm/min with tool's pin diameter 4${\Phi}$mm and 6${\Phi}$mm. The optimum mechanical property, ultimate stress,${\sigma}_Y$=470Mpa was obtained at the condition of 124mm/min of travel speed with 800rpm of tool rotation speed using full screw type pin, shoulder dia. 20${\Phi}$mm, pin dia.6${\Phi}$mm and pin length 6mm. The full-screw type and the half-screw type pin showed the similar behaviors of weldability. It is found that the size of nugget was depended on tool transition speed and tool dimension by macrostructures of the cross section of weld zone.

• Journal of Korean Foot and Ankle Society
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• v.19 no.1
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• pp.11-17
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• 2015

Purpose: To report the radiographic and clinical results of 6.5 mm cancellous full threaded buttress screw or Steinmann pin fixation to maintain a reduction of calcaneal posterior facet depression fracture. Materials and Methods: From June 2009 to June 2012, 50 consecutive cases with calcaneal joint depression fracture that underwent open reduction and screw or pin fixation were enrolled in this study. A 6.5 mm cancellous full threaded screw was inserted from the posteroinferior aspect of the calcaneal tuberosity to the posterior facet (group A) or Steinman pin was inserted from the posterosuperior aspect of the calcaneal tuberosity to the calcaneocuboidal joint (group B). Both preoperative and postoperative Bohler and Gissane angles were measured radiographically, and American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot scale on the final follow-up were assessed. Results: The mean age of patients was 44.1 years, and the mean follow-up period was 27.2 months. According to the Sanders classification, 28 cases were type II and 22 cases were type III. In Sanders type II, Bohler and Gissane angles improved significantly from $10.1^{\circ}$ and $126.2^{\circ}$ preoperatively to $27.2^{\circ}$ and $117.1^{\circ}$, respectively, in the immediate postoperative radiograph, and at the final follow-up, $26.6^{\circ}$ and $118.6^{\circ}$, respectively. In Sanders type III, Bohler and Gissane angles improved significantly from $5.0^{\circ}$ and $129.8^{\circ}$ to $29.9^{\circ}$ and $119.3^{\circ}$, respectively, in the immediate postoperative radiograph, and $26.9^{\circ}$ and $120.2^{\circ}$ at the final follow-up. All cases achieved bony union, and the average period until complete union was 13.3 weeks. AOFAS ankle-hindfoot scale was 82.6 in Sanders type II and 77.3 in Sanders type III at the final follow-up. Conclusion: A 6.5 mm cancellous full threaded buttress screw or Steinman pin fixation is a noninvasive treatment method with a merit of being able to maintain the bearing capacity of the posterior facet comparable to plate fixation.

• Clinics in Shoulder and Elbow
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• v.2 no.2
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• pp.133-137
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• 1999

Purpose: There are so many different methods with the their own advantages and disadvantages for acute AC dislocation and distal unstable clavicle fracture. We evaluated the usefulness of temporary Bosworth's coracoclavicular fixations using the cannulated screw and reviewed our clinical results. Materials and Methods: We evaluated 34 cases of temporary coracoclavicular fixations with cannulated screw and washer for acute AC dislocation(25cases in the Type V, Ⅲ) and distal unstable clavicle fracture(9cases in the Type ⅡB, Ⅱ+Ⅲ). All cases were fixed by the same techniques, guided cannulated screw under C-arm after the repair of the CC ligament within 1 week. Bases on the regular check, screws were removed at the 6-12 weeks under local anesthesia. The final clinical and radiological results(average 14 months follow-up) were rated with the UCLA scale. Results : All shoulders were gained nearly full ROM passively at the 3-4 weeks. The overall satisfactory resuIts(excellent or good) were achieved 88%(22/25) in the acute AC dislocation and all in the distal unstable clavicle fracture. There were no definite complications except three initial fixations loosening. Conclusion: Temporary Bosworth's coracoclavicular fixation using the cannulated screw with guided pin was simple precedure and provided enough initial stability for acute AC dislocation and distal unstable clavicle fracture.