Wyniki wyszukiwania - Biblioteka Nauki

1

Torsional deformation and rotary driving characteristics of SMA thin strip

100%

Tobushi H. , Pieczyska E. A. , Nowacki W. K. , Sakuragi T. , Sugimoto Y.

Archives of Mechanics

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2009

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tom Vol. 61, nr 3-4

241-257

EN

The torsional deformation properties of a TiNi shape-memory alloy thin strip were investigated. The results obtained are summarized as follows. (1) The martensitic transformation starts at the edge of the thin strip. (2) The torsional deformation properties change slightly under thermomechanical cycling. (3) The fatigue life in pulsating torsion is longer than that in alternating torsion. (4) A simple rotary driving element can be developed by using the SMA thin strip.

2

Two-way rotary shape memory alloy thin strip actuator

100%

Tobushi H. , Pieczyska E. A. , Nowacki W. K. , Date K. , Miyamoto K.

Journal of Theoretical and Applied Mechanics

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2010

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tom Vol. 48 nr 4

1043-1056

EN

In order to develop a two-way rotary shape memory alloy thin strip actuator, the torsional deformation and fatigue properties of a TiNi SMA thin strip were investigated. The results obtained are summarized as follows. (1) In the SMA thin strip subjected to torsion, the MT appears along the edge of the strip due to elongation of the edge of the strip and grows to the central part. (2) The number of cycles to failure decreases with an increase in the maximum angle of twist in torsion fatigue. The fatigue life in pulsating torsion is longer than that in alternating torsion by five times. The fatigue limit exists in a certain value of dissipated work of the strip in each cycle. (3) Based on the two-way motion of a lifting actuator model driven by two kinds of SMA thin strip, it is confirmed that the two-way rotary actuator with a small and simple mechanism can be developed by using the SMA thin strips.

PL

Wpracy zbadano termomechaniczne właściwości skręcania i zmęczenia stopu TiNi z pamięcią kształtu (SMA) w celu zbudowania skrętnego siłownika taśmowego zaprojektowanego na bazie dwukierunkowego efektu pamięci kształtu. Otrzymane wyniki podsumowano w sposób następujący. (1) W cienkich taśmach SMA poddawanych skręcaniu, przemiana martenzytyczna (MT) inicjuje się na krawędzi taśmy w związku ze składową rozciągania, a następnie rozwija w kierunku jej środka. (2) W badaniach zmęczeniowych ilość cykli do zniszczenia maleje wraz ze wzrostem maksymalnego kąta skręcania. Wytrzymałość na męczenie w przypadku skręcania pulsującego jest pięciokrotnie dłuższa niż w przypadku obciążania symetrycznego. (3) Przeprowadzone badania dwukierunkowego ruchu na zaprojektowanym modelu siłownika poruszanego przy pomocy dwóch rodzajów cienkiej taśmy SMA potwierdziły możliwość zbudowania skrętnego siłownika z małym i prostym mechanizmem na bazie dwukierunkowego efektu pamięci kształtu.

3

High speed twin roll caster for aluminum alloy thin strip

84%

Haga T. , Inui H. , Sakaguchi H. , Watari H. , Kumai S.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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tom Vol. 24, nr 1

365-371

EN

Purpose: In the present study, effectiveness of a high-speed twin roll caster for recycling aluminum alloy was investigated. Design/methodology/approach: The effects of the high-speed twin roll caster on alleviating the deterioration of mechanical properties by impurities were investigated. Properties of the cast strip were investigated by metallography, a tension test, and a bending test. Findings: A vertical type twin roll caster for strip casting of aluminum alloys was devised. The strip, which was thinner than 3 mm, could be cast at speeds higher than 60 m/min. Features of the twin roll casters are as below. Copper rolls were used and lubricant was not used in order to increase the casting speed. A casting nozzle was used to set the solidification length precisely. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Separating force was very small in order to prevent sticking of the strip to the roll. Low superheat casting was carried out in order to improve microstructure of the strip. In the present study, effectiveness of a high-speed and high-cooling rate twin roll caster of the present study for recycling aluminum alloy was investigated. Fe was added as impurity to 6063 and A356. The roll caster of the present study was useful to decrease the influence of impurity of Fe. Research limitations/implications: A high-speed twin roll caster of vertical type was designed and assembled to cast aluminum alloy thin strip. Originality/value: The results demonstrate that the high-speed twin roll caster can improve the deterioration by impurities.

4

High speed twin roll casting of 6016 aluminium alloy strip

67%

Sakaguchi H. , Haga T. , Watari H. , Kumai S.

Journal of Achievements in Materials and Manufacturing Engineering

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2007

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tom Vol. 20, nr 1-2

495-498

EN

Purpose: of this paper is to clear the possibility of high speed roll casting of aluminium alloy strip. In the body of the automobiles, a sheet of 6016 aluminium alloy is adopted for the outer panel. Therefore, casting of 6016 was tried in this study. Characteristics of roll cast 6016 were investigated. Design/methodology/approach: was a high speed twin roll caster. The high speed twin roll caster was designed to overcome the low castability of the twin roll caster. Findings: are as below. 6016 alloy could be cast into the strip continuously at the speed of 60 m/min. The thickness of the strip was 3.4 mm. The microstructure at as-cast and after T4 heat treatment was shown. The microstructure was very fine. The mechanical properties were investigated by the tensile test and 180 degrees vending test. The as-cast strip could be cold rolled without homogenization to 1 mm. Result of tensile test was tensile strength was 230MPa, 0.2% proof stress was 118MPa and elongation was 33%. 6016 strip of T4 heat treatment could be bent 180 degrees without occurrence of crack at the outer surface or breaking. Research limitations/implications: is the width of the strip was 100 mm. It is necesarry to test twin roll caster equipped wide rolls. Practical implications: are as below. The mechanical properites of the roll-cast 6016 were enough for the sheet metal for the automobile. The low productivity of the twin roller caster could be improved. Originality/value: is that 6016 strip could be cast continuously at speed 60 m/min and this strip had good mechanical properties.