scholarly journals Effects of Conventional Welding and Laser Welding on the Tensile Strength, Ultimate Tensile Strength and Surface Characteristics of Two Cobalt–Chromium Alloys: A Comparative Study

2012 ◽  
Vol 12 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Seenivasan Madhan Kumar ◽  
Jayesh Raghavendra Sethumadhava ◽  
Vaidyanathan Anand Kumar ◽  
Grover Manita
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Laser Welding ◽  
Comparative Study ◽  
Surface Characteristics ◽  
Cobalt Chromium ◽  
Chromium Alloys

scholarly journals Mechanical Properties of Laser-Sintered 3D-Printed Cobalt Chromium and Soft-Milled Cobalt Chromium

Prosthesis ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 313-320
Author(s):  
Abdullah Barazanchi ◽  
Kai Chun Li ◽  
Basil Al-Amleh ◽  
Karl Lyons ◽  
J. Neil Waddell
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elastic Modulus ◽  
Ultimate Tensile Strength ◽  
High Stress ◽  
Uniform Structure ◽  
Cobalt Chromium ◽  
Proof Stress ◽  
Fracture Surfaces ◽  
3D Printed

Purpose: To compare the mechanical properties and fracture behaviour of laser-sintered/3D-printed cobalt chromium (LS CoCr) with soft-milled cobalt chromium (SM CoCr) to assess their suitability for use in high-stress areas in the oral cavity. Material and Method: Two computer-aided manufacturing methods were used to fabricate dumbbell specimens in accordance with the ASTM standard E8. Specimens were fractured using tensile testing and elastic modulus, and proof stress and ultimate tensile strength were calculated. Fracture surfaces were examined using scanning electron microscopy. Plate specimens were also fabricated for the examination of hardness and elastic modulus using nanoindentation. Unpaired t-test was used to evaluate statistical significance. Results: LS CoCr specimens were found to have significantly higher ultimate tensile strength (UTS) and proof stress (PS) (p < 0.05) but not a significantly higher elastic modulus (p > 0.05). Examination of the dumbbell fracture surfaces showed uniform structure for the LS CoCr specimens whilst the SM CoCr specimens were perforated with porosities; neither showed an obvious point of fracture. Nanoindentation also showed that LS CoCr specimens possessed higher hardness compared with SM CoCr specimens. Conclusion: LS CoCr and SM CoCr specimens were both found to exhibit uniformly dense structure; although porosities were noted in the SM CoCr specimens. LS CoCr specimens were found to have superior tensile properties, likely due to lack of porosities, however both had mean values higher than those reported in the literature for cast CoCr. Uniformity of structure and high tensile strength indicates that LS CoCr and SM CoCr fabricated alloys are suitable for long-span metallic frameworks for use in the field of prosthodontics.

scholarly journals Comparative Study of the Fit Accuracy of Full-Arch Bar Frameworks Fabricated with Different Presintered Cobalt-Chromium Alloys

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Hang-Nga Mai ◽  
Tae-Yub Kwon ◽  
Min-Ho Hong ◽  
Du-Hyeong Lee
Keyword(s):  
Comparative Study ◽  
Machining Process ◽  
Mean Square ◽  
Cobalt Chromium ◽  
Arch Bar ◽  
Chromium Alloys ◽  
Structured Light Scanner ◽  
Reference Design ◽  
Soft Metal ◽  
Geometric Discrepancy

Purpose. This study was to measure the geometric discrepancies that occur during the sintering contraction of presintered Co-Cr alloys in a full-arch bar framework and to compare the variations between alloys from different manufacturers. Materials and Methods. Eighteen implant-supported full-arch bar frameworks were fabricated through a soft-machining process using presintered Co-Cr alloy blocks: Ceramill Sintron (CS), Soft Metal (SM), and Sintermetall (SML) (n=6 for each group). The sintered frameworks were digitized using a structured light scanner, and the scan images were superimposed on the reference design. The geometric discrepancies of the sintered frameworks were three-dimensionally analyzed for horizontal, angular, and internal discrepancies. Kruskal-Wallis and Mann–Whitney U tests were used to compare the discrepancies among the groups (α=.05). Results. Significant differences were found in the geometric discrepancy measurements among the groups. The CS group showed larger horizontal and angular discrepancies, followed by the SM and SML groups (P<.001). The root mean square (RMS) values for internal discrepancy were not statistically different among the groups (P=.778). Conclusion. The geometric discrepancies of full-arch bar frameworks fabricated using the soft-machining process were affected by accuracies in sintering contraction of presintered alloys.

An appraisal of characteristic mechanical properties and microstructure of friction stir welding for Aluminium 6061 alloy – Silicon Carbide (SiCp) metal matrix composite

2019 ◽  
Vol 13 (4) ◽  
pp. 5804-5817
Author(s):  
Ibrahim Sabry
Keyword(s):  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Metal Matrix Composite ◽  
Matrix Composite ◽  
Metal Matrix ◽  
Welded Joint ◽  
Rotation Speed ◽  
Fusion Welding ◽  
Friction Stir ◽  
Al 6061

It is expected that the demand for Metal Matrix Composite (MMCs) will increase in these applications in the aerospace and automotive industries sectors, strengthened AMC has different advantages over monolithic aluminium alloy as it has characteristics between matrix metal and reinforcement particles.  However, adequate joining technique, which is important for structural materials, has not been established for (MMCs) yet. Conventional fusion welding is difficult because of the irregular redistribution or reinforcement particles.  Also, the reaction between reinforcement particles and aluminium matrix as weld defects such as porosity in the fusion zone make fusion welding more difficult. The aim of this work was to show friction stir welding (FSW) feasibility for entering Al 6061/5 to Al 6061/18 wt. % SiCp composites has been produced by using stir casting technique. SiCp is added as reinforcement in to Aluminium alloy (Al 6061) for preparing metal matrix composite. This method is less expensive and very effective. Different rotational speeds,1000 and 1800 rpm and traverse speed 10 mm \ min was examined. Specimen composite plates having thick 10 mm were FS welded successfully. A high-speed steel (HSS) cylindrical instrument with conical pin form was used for FSW. The outcome revealed that the ultimate tensile strength of the welded joint (Al 6061/18 wt. %) was 195 MPa at rotation speed 1800 rpm, the outcome revealed that the ultimate tensile strength of the welded joint (Al 6061/18 wt.%) was 165 MPa at rotation speed 1000 rpm, that was very near to the composite matrix as-cast strength. The research of microstructure showed the reason for increased joint strength and microhardness. The microstructural study showed the reason (4 %) for higher joint strength and microhardness.  due to Significant   of SiCp close to the boundary of the dynamically recrystallized and thermo mechanically affected zone (TMAZ) was observed through rotation speed 1800 rpm. The friction stir welded ultimate tensile strength Decreases as the volume fraction increases of SiCp (18 wt.%).

VASCO 9-4-20

Alloy Digest ◽  
1997 ◽  
Vol 46 (10) ◽  
Keyword(s):  
Fracture Toughness ◽  
Tensile Strength ◽  
High Temperature ◽  
Ultimate Tensile Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
High Tensile Strength ◽  
Temperature Performance

Abstract Vasco 9-4-20 (0.20 wt% C) is a premium quality aircraft steel that combines high tensile strength with good fracture toughness. It is a heat-treatable alloy capable of developing an ultimate tensile strength greater than 190 ksi. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as heat treating, machining, and joining. Filing Code: SA-489. Producer or source: Vasco, An Allegheny Teledyne Company.

Microstructure and mechanical property improvement of dissimilar metal joints for TC4 Ti alloy to Nitinol NiTi alloy by laser welding

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yan Zhang ◽  
DeShui Yu ◽  
JianPing Zhou ◽  
DaQian Sun ◽  
HongMei Li
Keyword(s):  
Tensile Strength ◽  
Laser Welding ◽  
Mechanical Performance ◽  
Niti Alloy ◽  
Welding Process ◽  
Ti Alloy ◽  
The One ◽  
Fusion Weld ◽  
Welding Processes ◽  
Cu Interlayer

Abstract To avoid the formation of Ti-Ni intermetallics in a joint, three laser welding processes for Ti alloy–NiTi alloy joints were introduced. Sample A was formed while a laser acted at the Ti alloy–NiTi alloy interface, and the joint fractured along the weld centre line immediately after welding without filler metal. Sample B was formed while the laser acted on a Cu interlayer. The average tensile strength of sample B was 216 MPa. Sample C was formed while the laser acted 1.2 mm on the Ti alloy side. The one-pass welding process involved the creation of a joint with one fusion weld and one diffusion weld separated by the remaining unmelted Ti alloy. The mechanical performance of sample C was determined by the diffusion weld formed at the Ti alloy–NiTi alloy interface with a tensile strength of 256 MPa.

Processing Development and Properties of Cobalt-Chromium Alloys Fabricated by Traditional Method

2021 ◽  
Vol 43 ◽  
pp. 2629-2634
Author(s):  
Wanwilai Vittayakorn ◽  
Phieraya Poolphol ◽  
Kantapon Aimprakod ◽  
Tosapol Maluangnont
Keyword(s):  
Traditional Method ◽  
Cobalt Chromium ◽  
Chromium Alloys
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