Maruemu Works Co.

Ōsaka, Japan

Maruemu Works Co.

Ōsaka, Japan
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Patent
Maruemu Works Co. and Tohoku Techno Arch Co. | Date: 2015-02-05

The present invention provides a dental member, which has a reduced size, and thus prevents damages to tooth roots upon implantation, has high strength and low elasticity, and is excellent in engraftment stability after implantation. The dental member is produced with an amorphous alloy having a composition represented by formula: Zr_(a)Ni_(b)Cu_(c)Al_(d )[wherein a ranges from 60 to 75 at. %, b ranges from 11 to 30 at. %, c ranges from 1 to 16 at. %, and d ranges from 5 to 20 at. %] and is used as an orthodontic anchor screw wherein the screw part has a core diameter of 0.5-1.0 mm or a length of 2-5 mm, a one-piece-type dental implant wherein the screw part has the largest diameter of 0.5-2.9 mm and a length of 2-13.4 mm, or a two-piece-type dental implant wherein the screw part has the largest diameter of 0.5-2.9 mm and a length of 2-5.9 mm.


Hashimura S.,Shibaura Institute of Technology | Torn T.,Kurume National College of Technology | Miyashita Y.,Nagaoka University of Technology | Yamanaka S.,Maruemu Works. Co. | Hibi G.,Maruemu Works. Co.
Key Engineering Materials | Year: 2014

Fatigue characteristics of bolted joint tightened with a steel bolt have been discussed extensively. However the fatigue characteristics of bolted joint tightened with a nonferrous bolt have not been sufficiently discussed. In this study, two types of fatigue tests, axial fatigue tests and transverse fatigue tests, for nonferrous bolts were conducted. The nonferrous bolts used in this study made of AZ31 and AZX912 magnesium alloy and A5056 aluminum alloy. The results of both fatigue tests showed that the fatigue limits of the A5056 bolt were the highest of all. The fatigue limits of two kinds of the magnesium alloy bolts were almost the same in both fatigue tests. However the ration of the axial fatigue limits to the transverse fatigue limits were different according to the bolt materials. © (2014) Trans Tech Publications.


Narita K.,Tohoku University | Narita K.,Maruemu Works Co. | Niinomi M.,Tohoku University | Nakai M.,Tohoku University
Materials Science and Engineering A | Year: 2015

This study investigates the effect of heterogeneous precipitation induced by the segregation of substitutional and interstitial elements in Ti-29Nb-13Ta-4.6Zr alloy (TNTZ) on its mechanical properties. For this, samples both with and without segregation of substitutional elements were prepared, with only the latter being subjected to long-term homogenization. It was found that micro-scale segregation of substitutional elements such as Nb, Ta, and Zr does not significantly affect mechanical properties such as fatigue strength, not even if heterogeneous precipitation occurs as a result of this segregation. On the other hand, segregation of interstitial elements was achieved by controlling the aging time. The segregation of interstitial elements creates precipitate-free zones (PFZs), grain boundary (GB) plates, and Widmanstätten α phases with migrating O atoms that all significantly affect the mechanical properties. Specifically, the PFZs have the potential to improve fatigue life, while the Widmanstätten α phase increases the tensile strength and reduces the fatigue ratio, the GB-plates reduce elongation, These results indicate that the formation of a Widmanstätten α phase by the migration of interstitial elements has a varying influence on the tensile and fatigue properties. © 2015 Elsevier B.V.


Yamanaka S.,Maruemu Works Co. | Yamanaka S.,Tohoku University | Amiya K.,Tohoku University | Saotome Y.,Tohoku University | Inoue A.,Tohoku University
Materials Transactions | Year: 2011

Bolts are commonly employed machine elements used for joining and fastening, and their performance and reliability influence the overall performance of machines. In this study, we have plastically worked and formed bolts using metallic glass (MG) that exhibits unique mechanical properties such as high tensile strength, low Young's modulus, and large elastic limit. The large elastic limit increases the permissible elongation range of the bolt and helps avoid bolt loosening, while the low Young's modulus effectively resists screwed-in bolt loosening by increasing the frictional forces on both bolt-nut contact area and bearing surface. We employed a zirconium-based MG Zr 55Al10Cu30Ni5 for our experimental investigations. A pre-form of a hexagon socket head cap screw (bolt) was fabricated by squeeze casting. Cold and warm thread rolling were performed to form a metric screw thread M3×0.5 (class 6g (ISO)) below the glass transition temperature (7'g) using a flat rolling machine. Despite the extremely poor ductility of MG at room temperature, thread rolling was successfully performed. Straining behavior analysis by a three-dimensional finite element method demonstrated that these remarkable results are due to the compressive stress distribution induced during the thread rolling process. In addition, thread rolling is fundamentally an incremental process, and it enhances the deformability of MG by gradually improving ductility in the deformed region. The tensile strength of the thread-rolled bolt was approximately 1600MPa, which is considerably higher than that of conventional heat-treated high strength steel bolts. MG was thus successfully employed to manufacture improved bolts. © 2011 The Japan Institute of Metals.


Yamanaka S.,Maruemu Works Co. | Amiya K.,Tohoku University | Saotome Y.,Tohoku University
Journal of Materials Processing Technology | Year: 2014

Metallic glass (MG) has unique mechanical properties, combining high strength and low Young's modulus. By using MG to fabricate fasteningbolts, high resistance against bolt loosening is expected. However, MG components are considered brittle because MG exhibits poor ductility when subjected to uniaxial loading at room temperature. We have developed hexagonal cap bolts made of zirconium-based MG by cold thread rolling. The MG bolts showed a 1.6% plastic strain with a tensile strength of more than 1550 MPa. In addition, the load-strain curve was similar to that of a strain hardening material, although MG itself is free of strain hardening. In this study, we attempted to clarify the reasons for these characteristics, which are advantageous for bolts in terms of toughness and reliability. Various experiments and numerical analysis indicated that residual stress plays an important role in the behavior. © 2014 Elsevier B.V.


Patent
Maruemu Works Co. and Tohoku University | Date: 2012-11-28

Provided is a metallic glass fastening screw that is added with the property not susceptible to loosening, and is capable of implementing fastening with high strength and reliability in lightweight members and other members in various fields. In processing a screw thread and a screw groove of a screw, amorphous bulk metallic glass is form-rolled at glass transition temperature or less of the bulk metallic glass as a process material. The bulk metallic glass has the property that plastic strain is introduced by plastic working such as form rolling, so as to improve ductility in a region including a slip band. By effectively using this property, a relationship of d > 0.022 x D is made to hold provided that a depth from a bottom of the screw groove in the region where the plastic strain is introduced by the form rolling is d and an outside diameter of the screw is D, in order to relax stress concentration of tensile stress generated in a region at the bottom of the screw groove due to tension (axial force) applied to the screw in fastening.


Patent
Tohoku University and Maruemu Works Co. | Date: 2010-06-22

A metallic glass fastening screw that is not susceptible to loosening, and is capable of implementing fastening with high strength and reliability. In processing a screw thread and a screw groove of a screw, amorphous bulk metallic glass is form-rolled at glass transition temperature or less of the bulk metallic glass serving as a member to be processed. The bulk metallic glass has a plastic strain property introduced by plastic working such as form rolling, to improve ductility. A relationship of d>0.022D is set so that a depth from a bottom of the screw groove in the region where the plastic strain is introduced is d and an outside diameter of the screw is D, to relax stress concentration of tensile stress generated in a region at the bottom of the screw groove due to tension (axial force) applied to the screw in fastening.


Patent
Rocky Mountain Morita Corporation and Maruemu Works Co. | Date: 2014-08-29

A jaw repositioning appliance has a maxillary plate fit to a maxilla, a mandibular plate fit to a mandible, and at least one connecting wire constituted with a wire rod, which has the Youngs modulus of 100 GPa or lower, which has tensile strength value of 0.01 or higher with respect to the Youngs modulus, and which can deform elastically. The connecting wire has at least one curved portion. One end (34, 44) of the connecting wire is attached to the maxillary plate and the other end of the connecting wire is attached to the mandibular plate.


Arimoto K.,Arimotech Ltd. | Ikuta F.,NETUREN Co. | Yamanaka S.,Maruemu Works Co.
International Journal of Microstructure and Materials Properties | Year: 2012

Gas nitriding is well established as a suitable process for realisinglow distortion in precision parts under optimal conditions. However, efforts for optimising the distortions by trial and error, which are not avoidable, have been repeated over many years. A software tool based on the finite element method is developed by use of the latest models of nitriding for resolving the problems, which was applied to the nitrided austenitic stainless steels specimens. In this study, distortions in nitrided steel cylinders, which were measured systematically in 1930s, were investigated using the tool for understanding their tendencies derived from different conditions. The fruits will be used for enhancing the tool by additional verifications, and applying finally to distortion problems in practical parts. Copyright © 2012 Inderscience Enterprises Ltd.


Hashimura S.,Nagaoka University | Miyashita Y.,Nagaoka University | Kurakake Y.,Kurume National College of Technology | Yamanaka S.,Maruemu Works. Co. | Hibi G.,Maruemu Works. Co.
SAE Technical Papers | Year: 2012

In this study, tightening tests for four types of commercial bolts made of nonferrous materials were conducted to investigate torque coefficients that show the tightening accuracy. These four types of bolts were made of AZ31 and AZX912 magnesium alloy, A5056 aluminum alloy and TB340 pure titanium respectively. Materials for the clamped parts corresponded to the bolts: AZ31 magnesium alloy, A5056 aluminum alloy and TB340 pure titanium. These clamped parts were tightened by bolts and nuts of the same material except when using AZX912 bolts, in which case AZ31 nuts and AZ31 clamped parts were used. Tightening tests using A5056 clamped parts with magnesium alloy bolts were also conducted to verify the usefulness of the magnesium alloy bolt in the tightening of aluminum parts. Tensile tests for all bolts were conducted to investigate the difference between their tensile strength and tightening strength. The results showed that if an A5056 clamped part was tightened with an A5056 bolt, the scatter band of its torque coefficient was the widest. However the scatter band of the torque coefficient in the experiment using an A5056 clamped part tightened with an AZ31 bolt or AZX912 bolt was reduced. The torque coefficient for the TB340 bolt was the twice as much as in other cases. The results also showed that the tightening strength of the magnesium alloy bolts was greater than that of the aluminum alloy bolts although the tensile strength was lower. These results indicate that there may be an increase in the use of magnesium alloy bolts. Copyright © 2012 SAE International.

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