Baoji Hongtech Titanium & Nickel Metal Co,. Ltd |
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Shape-memory alloys are metals that, even if they become deformed
at below a given temperature, they will return to their original
shape before deformation simply by being heated. Alloys with this
unusual characteristic are used as functional materials in
temperature sensors, actuators, and clamping fixtures.
These metals also have a quality called superelasticity; like
rubber, when it is bent or stretched, it will return to its
original shape when the deforming force is removed. This
characteristic of recovering shape despite substantial deformation
is exploited in applications in products for daily life, in
electrical and electronic appliances, and in the medical field.
There currently are several dozen types of alloys with such
shape-memory properties and superelasticity, but Ni-Ti alloys have
the best shape-recovery performance, durability, and
corrosion-resistance.
Born of our wealth of titanium and titanium alloy melting and
fabrication technology, ABC-Ti is one of the most reliable of
the Ni-Ti alloys of this type of shape-memory and superelastic
alloys.
The shape-memory effect and superelasticity are the result of thermo-elastic martensitic transformation, in which the shape-memory effect is expressed as phase transformation and reverse transformation from the parent phase (austenite) to and from the martensite phase. Superelasticity is expressed as stress-induced transformation from the parent phase to a martensite phase due to load stress in the parent phase state, and then as reverse transformation when unloaded.
Typical behaviors are explained below using a stress-strain curve:
Density | 6.4 to 6.5 [g/cm3] | |
---|---|---|
Specific heat | 0.3 [kJ/(kg·K)] | |
Electric resistance | 0.5 to 1.1 [10-6Ω·m] | |
Thermal Conductance | 21 [W/(m·K)] | |
Linear expansion coefficient | 10 [10-6/K] | |
Modulus of transverse elasticity | Martensite phase | 5 to 10 [GPa] |
Austenite phase | 15 to 25 [GPa] | |
Young’s modulus | Martensite phase | 15 to 30 [GPa] |
Austenite phase | 50 to 70 [GPa] | |
Hardness | Martensite phase | 180 to 300 [Hv] |
Austenite phase | 300 to 400 [Hv] | |
Rupture stress | Martensite phase | 700 to 1000 [MPa] |
Austenite phase | 1200 to 1500 [MPa ] | |
Elongation | Martensite phase | Up to 30 [%} |
Austenite phase | Up to 20 [%] |
We have prepared a line according to their shape-memory and superelasticity characteristics.
Effect | Metal alloys | Transformation temperature (℃) | Recoverable strain (%) | Temperature hysteresis (℃) | Temperature Cycle Properties | Application examples |
---|---|---|---|---|---|---|
Shape Memory Effect | NiTi NiTi-Co | -20 to 70 | 1 | 2 to 3 | >1,000,000 | Sensor actuator (Long life cycle) |
NiTi-Cu | 40 to 80 | 5 to 6 | 10 to 15 | <50,000 | Sensor actuator (Large stroke) | |
NiTi | -10 to 100 | 6 to 8 | 20 to 40 | <100 | connectors Couplings | |
Superelasticity | NiTi NiTi-Co,V,Cr | − | 6 to 8 | − | − | Various spring elements |
Substantial shape-memory and recoverable strain.
These alloys have superb corrosion resistance and wear resistance that is nearly equivalent to those of titanium and titanium alloys. They also have vastly superior wear resistance to wear-resistant materials such as titanium and nickel alloys.
We aspire to a total quality control system through an integrated manufacturing system from melting the parent material to the final treated shape-memory product.
We can use our accumulated database to consult with customers to meet their needs from device design through prototyping.
We can provide a variety of diverse shapes, including round wire, square wire, ultrafine wire (from φ0.02mm), ribbon, coil springs, and 3D shapes.
fields of application
Shape-memory alloys | Superelastic alloys | |
---|---|---|
Consumer electronics | Coffee makers | Mobile phone antennas |
Industrial machinery | Pipe seams, fire dampers | |
Household equipment | Mixing water faucets, gas water heaters, water regulator valves, subfloor vents, hot water shutoff valves for water purifiers | |
Transport machinery and equipment | Evaporative emission control systems | |
Personal accessories | Brassiere underwires, eyeglass frames, shoulder pad wires, petticoats, accessories | |
Medical equipment | Dental implants | Orthodontic braces wire, Guide wires |
Hobbies | Toys | Spinner lures, fishing through-wire |