SEARCH · Engineering Papers

Results for “Ni-Ti”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2

All sources NASA NTRS DOE OSTI

NASA NTRS2004

Design and Control of a Proof-of-Concept Active Jet Engine Intake Using Shape Memory Alloy Actuators

The design and control of a novel proof-of-concept active jet engine intake using Nickel-Titanium (Ni-Ti or Nitinol) shape memory alloy (SMA) wire actuators is used to demonstrate the potential of an adaptive intake to improve the fuel efficiency of a jet engine. The Nitinol SMA material is selected for this research due to the material's ability to generate large strains of up to 5 percent for repeated operations, a high power-to-weight ratio, electrical resistive actuation, and easy fabrication into a variety of shapes. The proof-of-concept engine intake employs an overlapping leaf design arranged in a concentric configuration. Each leaf is mounted on a supporting bar that rotates upon actuation by SMA wires electrical resistive heating. Feedback control is enabled through the use of a laser range sensor to detect the movement of a leaf and determine the radius of the intake area. Due to the hysteresis behavior inherent in SMAs, a nonlinear robust controller is used to direct the SMA wire actuation. The controller design utilizes the sliding-mode approach to compensate for the nonlinearities associated with the SMA actuator. Feedback control experiments conducted on a fabricated proof-of-concept model have demonstrated the capability to precisely control the intake area and achieve up to a 25 percent reduction in intake area. The experiments demonstrate the feasibility of engine intake area control using the proposed design.

Song, Gangbing↗

NASA NTRS1991

Shape-memory alloy micro-actuator

A method of producing an integral piece of thermo-sensitive material, which is responsive to a shift in temperature from below to above a phase transformation temperature range to alter the material's condition to a shape-memory condition and move from one position to another. The method is characterized by depositing a thin film of shape-memory material, such as Nickel titanium (Ni-Ti) onto a substrate by vacuum deposition process such that the alloy exhibits an amorphous non-crystalline structure. The coated substrate is then annealed in a vacuum or in the presence of an inert atmosphere at a selected temperature, time and cool down rate to produce an ordered, partially disordered or fully disordered BCC structure such that the alloy undergoes thermoelastic, martinsetic phase transformation in response to alteration in temperature to pass from a martinsetic phase when at a temperature below a phase transformation range and capable of a high level of recoverable strain to a parent austenitic phase in a memory shape when at a temperature above the phase transformation range. Also disclosed are actuator devices employing shape-memory material actuators that deform from a set shape toward an original shape when subjected to a critical temperature level after having been initially deformed from the original shape into the set shape while at a lower temperature. The actuators are mechanically coupled to one or more movable elements such that the temperature-induce deformation of the actuators exerts a force or generates a motion of the mechanical element(s).

Busch, John D.↗

NASA NTRS2012

Curved Waveguide Based Nuclear Fission for Small, Lightweight Reactors

The focus of the presented work is on the creation of a system of grazing incidence, supermirror waveguides for the capture and reuse of fission sourced neutrons. Within research reactors, neutron guides are a well known tool for directing neutrons from the confined and hazardous central core to a more accessible testing or measurement location. Typical neutron guides have rectangular, hollow cross sections, which are crafted as thin, mirrored waveguides plated with metal (commonly nickel). Under glancing angles with incoming neutrons, these waveguides can achieve nearly lossless transport of neutrons to distant instruments. Furthermore, recent developments have created supermirror surfaces which can accommodate neutron grazing angles up to four times as steep as nickel. A completed system will form an enclosing ring or spherical resonator system to a coupled neutron source for the purpose of capturing and reusing free neutrons to sustain and/or accelerate fission. While grazing incidence mirrors are a known method of directing and safely using neutrons, no method has been disclosed for capture and reuse of neutrons or sustainment of fission using a circular waveguide structure. The presented work is in the process of fabricating a functional, highly curved, neutron supermirror using known methods of Ni-Ti layering capable of achieving incident reflection angles up to four times steeper than nickel alone. Parallel work is analytically investigating future geometries, mirror compositions, and sources for enabling sustained fission with applicability to the propulsion and energy goals of NASA and other agencies. Should research into this concept prove feasible, it would lead to development of a high energy density, low mass power source potentially capable of sustaining fission with a fraction of the standard critical mass for a given material and a broadening of feasible materials due to reduced rates of release, absorption, and non-fission for neutrons. This advance could be applied to direct propulsion through guided fission products or as a secondary energy source for high impulse electric propulsion. It would help meet national needs for highly efficient energy sources with limited dependence on fossil fuels or conflict materials, and it would improve the use of low grade fissile materials which would help reduce national stockpiles and waste.

Coker, Robert↗

NASA NTRS2016

Cu-Al-Ni Shape Memory Single Crystal Wires with High Transformation Temperature

CN-250X is a new material with higher performance than Nickel-Titanium Shape Memory Alloy (SMA). For space mechanisms, the main disadvantage of Nickel-Titanium Shape Memory Alloy is the limited transformation temperature. The new CN-250X Nimesis alloy is a Cu-Al-Ni single crystal wire available in large quantity because of a new industrial process. The triggering of actuators made with this Cu-Al-Ni single crystal wire can range from ambient temperature to 200 C in cycling and even to 250 C in one-shot mode. Another advantage of CN-250X is a better shape recovery (8 to 10%) than Ni-Ti (6 to 7%). Nimesis is the first company able to produce this type of material with its new special industrial process. A characterization study is presented in this work, including the two main solicitation modes for this material: tensile and torsion. Different tests measure the shape recovery of Cu-Al-Ni single crystals wires during heating from room temperature to a temperature higher than temperature of end of martensitic transformation.

Hautcoeur, Alain↗

NASA NTRS2016

Cooling Rate Study of Nickel-Rich Material During Thermal Treatment and Quench

To investigate quench cracking that results from water quenching after heat treatment of binary and Ni-rich material, cooling rates of specimens were measured during quenching and hardness post-thermal treatment. For specific applications binary Ni-Ti is customarily thermally treated and quenched to attain desired mechanical properties and hardness. However, one problem emerging from this method is thermal cracking, either during the heat treatment process or during the specimen's application. This can result in material and equipment failure as well as financial losses. The objective of the study is to investigate the internal cooling rate of 60-NiTi during quenching and determine possible factors causing thermal cracking. Cubic (1 in.3) samples of both material were heat treated in air at 1000 deg C for 2 hrs and quenched in room temperature water using two methods: (1) dropped in the water and (2) agitated in the water. Hardness of the two fore-mentioned methods was measured post heat treatment. Results indicate that the quenching method had an effect on cooling rate during quenching but hardness was observed to be essentially the same through the thickness of the samples.

Thermal Crack↗

NASA NTRS2017

Hardness and Second Phase Percentage of Ni-Ti-Hf Compounds After Heat Treatment at 700C

The Vickers hardness and second phase precipitation of three ternary intermetallic Ni-Ti-Hf compounds containing either 1, 3 or 5 at.% Hf were compared to 60-Nitinol (55 at.% Ni - 45 at.% Ti). Heat treatment either at 700 C or with a subsequent aging step, hardened the 3 and 5 at.% Hf-containing ternaries to approximately 620 HV (56 HRC). Heat treatment increased the hardness of the 1 at.% Hf compound by more than 25 percent. Average hardness of the 3 and 5 at.% Hf ternaries, though higher than that of the binary Ni-Ti or the Ni-Ti-Hf compound containing 1 at.% Hf, appeared to be fairly insensitive to the different heat treatments. There was a drastic reduction of fatigue-enhancing second phase precipitates for the 5 at.% Hf ternaries compared to the other compounds. These results should guide materials selection for development of aerospace componentry.

intermetallics↗

NASA NTRS2017

NiTi Alloys: New Materials that enable Shockproof, Corrosion Immune Bearings

Though steel is the dominant material of choice for mechanical components (bearings and gears) it has intrinsic limitations related to corrosion and plastic deformation. In contrast, dimensionally stable nickel-rich Ni-Ti alloys, such as Nitinol 60, are intrinsically rustproof and can withstand high contact loads without damage (denting). Over the last decade, focused RD to exploit these alloys for new applications has revealed the science behind NiTi's remarkable properties. In this presentation, the state-of-the-art of nickel-rich NiTi alloys will be introduced along with a discussion of how NASA is adopting this new technology inside the space station water recycling system as a pathfinder for more down-to-earth tribological challenges.

bearings↗

DOE OSTI2020

Materials Data on TiNi3 by Materials Project

Ni3Ti is Uranium Silicide-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Ti sites. In the first Ti site, Ti is bonded to twelve Ni atoms to form TiNi12 cuboctahedra that share corners with twelve equivalent TiNi12 cuboctahedra, edges with twenty-four NiTi4Ni8 cuboctahedra, faces with six equivalent TiNi12 cuboctahedra, and faces with twelve NiTi4Ni8 cuboctahedra. All Ti–Ni bond lengths are 2.55 Å. In the second Ti site, Ti is bonded to twelve Ni atoms to form TiNi12 cuboctahedra that share corners with six equivalent TiNi12 cuboctahedra, corners with twelve NiTi4Ni8 cuboctahedra, edges with eighteen NiTi4Ni8 cuboctahedra, faces with eight TiNi12 cuboctahedra, and faces with twelve NiTi4Ni8 cuboctahedra. There are six shorter (2.55 Å) and six longer (2.57 Å) Ti–Ni bond lengths. There are six inequivalent Ni sites. In the first Ni site, Ni is bonded to four Ti and eight Ni atoms to form NiTi4Ni8 cuboctahedra that share corners with four equivalent TiNi12 cuboctahedra, corners with fourteen NiTi4Ni8 cuboctahedra, edges with six TiNi12 cuboctahedra, edges with twelve NiTi4Ni8 cuboctahedra, faces with four TiNi12 cuboctahedra, and faces with sixteen NiTi4Ni8 cuboctahedra. There are four shorter (2.53 Å) and four longer (2.55 Å) Ni–Ni bond lengths. In the second Ni site, Ni is bonded to four Ti and eight Ni atoms to form NiTi4Ni8 cuboctahedra that share corners with four equivalent TiNi12 cuboctahedra, corners with fourteen NiTi4Ni8 cuboctahedra, edges with six TiNi12 cuboctahedra, edges with twelve NiTi4Ni8 cuboctahedra, faces with four TiNi12 cuboctahedra, and faces with sixteen NiTi4Ni8 cuboctahedra. There are four shorter (2.53 Å) and two longer (2.55 Å) Ni–Ni bond lengths. In the third Ni site, Ni is bonded to four Ti and eight Ni atoms to form distorted NiTi4Ni8 cuboctahedra that share corners with twelve NiTi4Ni8 cuboctahedra, edges with eight TiNi12 cuboctahedra, edges with sixteen NiTi4Ni8 cuboctahedra, faces with four TiNi12 cuboctahedra, and faces with fourteen NiTi4Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.47–2.62 Å. In the fourth Ni site, Ni is bonded to four Ti and eight Ni atoms to form distorted NiTi4Ni8 cuboctahedra that share corners with twelve equivalent NiTi4Ni8 cuboctahedra, edges with eight TiNi12 cuboctahedra, edges with sixteen NiTi4Ni8 cuboctahedra, faces with four TiNi12 cuboctahedra, and faces with fourteen NiTi4Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.47–2.62 Å. In the fifth Ni site, Ni is bonded to four Ti and eight Ni atoms to form distorted NiTi4Ni8 cuboctahedra that share corners with twelve NiTi4Ni8 cuboctahedra, edges with eight TiNi12 cuboctahedra, edges with sixteen NiTi4Ni8 cuboctahedra, faces with four TiNi12 cuboctahedra, and faces with fourteen NiTi4Ni8 cuboctahedra. There are a spread of Ni–Ni bond distances ranging from 2.47–2.62 Å. In the sixth Ni site, Ni is bonded to four Ti and eight Ni atoms to form NiTi4Ni8 cuboctahedra that share corners with four equivalent TiNi12 cuboctahedra, corners with fourteen NiTi4Ni8 cuboctahedra, edges with six TiNi12 cuboctahedra, edges with twelve NiTi4Ni8 cuboctahedra, faces with four TiNi12 cuboctahedra, and faces with sixteen NiTi4Ni8 cuboctahedra.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ti2Ni by Materials Project

Ti2Ni crystallizes in the cubic Fd-3m space group. The structure is three-dimensional. there are two inequivalent Ti sites. In the first Ti site, Ti is bonded in a 12-coordinate geometry to six equivalent Ni atoms. All Ti–Ni bond lengths are 2.48 Å. In the second Ti site, Ti is bonded in a 2-coordinate geometry to two equivalent Ni atoms. Both Ti–Ni bond lengths are 2.59 Å. Ni is bonded in a 12-coordinate geometry to six Ti atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on TiNi by Materials Project

NiTi is alpha iridium vanadium-like structured and crystallizes in the trigonal P-3 space group. The structure is three-dimensional. there are three inequivalent Ti sites. In the first Ti site, Ti is bonded in a body-centered cubic geometry to eight Ni atoms. There are six shorter (2.50 Å) and two longer (2.66 Å) Ti–Ni bond lengths. In the second Ti site, Ti is bonded in a 8-coordinate geometry to eight Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.43–2.88 Å. In the third Ti site, Ti is bonded in a distorted body-centered cubic geometry to eight Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.51–2.73 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded in a body-centered cubic geometry to eight Ti atoms. In the second Ni site, Ni is bonded in a 8-coordinate geometry to eight Ti and three equivalent Ni atoms. All Ni–Ni bond lengths are 2.73 Å. In the third Ni site, Ni is bonded in a distorted body-centered cubic geometry to eight Ti and one Ni atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on TiNi by Materials Project

NiTi is alpha iridium vanadium-like structured and crystallizes in the trigonal P3 space group. The structure is three-dimensional. there are five inequivalent Ti sites. In the first Ti site, Ti is bonded in a distorted body-centered cubic geometry to eight Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.50–2.83 Å. In the second Ti site, Ti is bonded in a 8-coordinate geometry to eight Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.44–2.89 Å. In the third Ti site, Ti is bonded in a distorted body-centered cubic geometry to eight Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.51–2.81 Å. In the fourth Ti site, Ti is bonded in a distorted body-centered cubic geometry to eight Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.51–2.76 Å. In the fifth Ti site, Ti is bonded in a distorted body-centered cubic geometry to eight Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.50–2.71 Å. There are five inequivalent Ni sites. In the first Ni site, Ni is bonded in a 8-coordinate geometry to eight Ti atoms. In the second Ni site, Ni is bonded in a 8-coordinate geometry to eight Ti atoms. In the third Ni site, Ni is bonded in a 8-coordinate geometry to eight Ti atoms. In the fourth Ni site, Ni is bonded in a 8-coordinate geometry to eight Ti atoms. In the fifth Ni site, Ni is bonded in a distorted body-centered cubic geometry to eight Ti atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ti3Ni by Materials Project

Ti3Ni is Uranium Silicide structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Ti is bonded to eight equivalent Ti and four equivalent Ni atoms to form TiTi8Ni4 cuboctahedra that share corners with twelve equivalent TiTi8Ni4 cuboctahedra, edges with eight equivalent NiTi12 cuboctahedra, edges with sixteen equivalent TiTi8Ni4 cuboctahedra, faces with four equivalent NiTi12 cuboctahedra, and faces with fourteen equivalent TiTi8Ni4 cuboctahedra. All Ti–Ti bond lengths are 2.78 Å. All Ti–Ni bond lengths are 2.78 Å. Ni is bonded to twelve equivalent Ti atoms to form NiTi12 cuboctahedra that share corners with twelve equivalent NiTi12 cuboctahedra, edges with twenty-four equivalent TiTi8Ni4 cuboctahedra, faces with six equivalent NiTi12 cuboctahedra, and faces with twelve equivalent TiTi8Ni4 cuboctahedra.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ti3Ni4 by Materials Project

Ni4Ti3 is delta Molybdenum Boride-like structured and crystallizes in the trigonal R-3 space group. The structure is three-dimensional. Ti is bonded in a 9-coordinate geometry to nine Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.44–2.72 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded in a 6-coordinate geometry to six equivalent Ti and eight Ni atoms. There are two shorter (2.52 Å) and six longer (2.92 Å) Ni–Ni bond lengths. In the second Ni site, Ni is bonded in a 8-coordinate geometry to six equivalent Ti and two equivalent Ni atoms. In the third Ni site, Ni is bonded in a 7-coordinate geometry to seven equivalent Ti and one Ni atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on TiNi by Materials Project

NiTi is Tetraauricupride structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. Ti is bonded in a body-centered cubic geometry to eight equivalent Ni atoms. All Ti–Ni bond lengths are 2.59 Å. Ni is bonded in a body-centered cubic geometry to eight equivalent Ti atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on TiNi by Materials Project

NiTi is beta-prime cadmium gold structured and crystallizes in the orthorhombic Pmma space group. The structure is three-dimensional. Ti is bonded in a 8-coordinate geometry to eight equivalent Ni atoms. There are six shorter (2.56 Å) and two longer (2.78 Å) Ti–Ni bond lengths. Ni is bonded in a 12-coordinate geometry to eight equivalent Ti atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on TiNi by Materials Project

NiTi is beta-prime cadmium gold structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are three inequivalent Ti sites. In the first Ti site, Ti is bonded in a 12-coordinate geometry to eight Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.52–3.05 Å. In the second Ti site, Ti is bonded in a 12-coordinate geometry to seven Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.56–2.67 Å. In the third Ti site, Ti is bonded in a 12-coordinate geometry to eight Ni atoms. There are a spread of Ti–Ni bond distances ranging from 2.51–3.06 Å. There are three inequivalent Ni sites. In the first Ni site, Ni is bonded in a 12-coordinate geometry to eight Ti and four Ni atoms. There are a spread of Ni–Ni bond distances ranging from 2.68–2.74 Å. In the second Ni site, Ni is bonded in a 12-coordinate geometry to eight Ti and four Ni atoms. There are one shorter (2.62 Å) and three longer (2.74 Å) Ni–Ni bond lengths. In the third Ni site, Ni is bonded in a 12-coordinate geometry to seven Ti and two Ni atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on TiNi by Materials Project

NiTi is Tetraauricupride structured and crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. Ti is bonded to eight equivalent Ni atoms to form a mixture of distorted corner, edge, and face-sharing TiNi8 cuboctahedra. There are a spread of Ti–Ni bond distances ranging from 2.61–2.65 Å. Ni is bonded to eight equivalent Ti atoms to form a mixture of distorted corner, edge, and face-sharing NiTi8 cuboctahedra.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on TiNi by Materials Project

NiTi is Tetraauricupride structured and crystallizes in the orthorhombic Pmmn space group. The structure is three-dimensional. Ti is bonded to four equivalent Ti and eight equivalent Ni atoms to form distorted TiTi4Ni8 cuboctahedra that share corners with twelve equivalent TiTi4Ni8 cuboctahedra, edges with eight equivalent TiTi4Ni8 cuboctahedra, edges with sixteen equivalent NiTi8Ni4 cuboctahedra, faces with eight equivalent NiTi8Ni4 cuboctahedra, and faces with ten equivalent TiTi4Ni8 cuboctahedra. All Ti–Ti bond lengths are 2.71 Å. There are a spread of Ti–Ni bond distances ranging from 2.59–2.71 Å. Ni is bonded to eight equivalent Ti and four equivalent Ni atoms to form distorted NiTi8Ni4 cuboctahedra that share corners with twelve equivalent NiTi8Ni4 cuboctahedra, edges with eight equivalent NiTi8Ni4 cuboctahedra, edges with sixteen equivalent TiTi4Ni8 cuboctahedra, faces with eight equivalent TiTi4Ni8 cuboctahedra, and faces with ten equivalent NiTi8Ni4 cuboctahedra. All Ni–Ni bond lengths are 2.70 Å.

36 MATERIALS SCIENCE↗