Shenzhen Wuge Industrial Co., Ltd

Nitinol memory alloy has been widely used in medical, aerospace and other fields due to its unique shape memory effect, superelasticity and corrosion resistance. Applying it to the field of gas-liquid filtration can explore the use of its characteristics to solve the pain points of traditional filter screens, such as easy clogging, difficult cleaning, and insufficient structural stability. The following analysis will be conducted from the aspects of application advantages, design ideas, key technologies, and potential challenges:

1、 Characteristics and filtration application advantages of nickel titanium memory alloy

1. Shape memory effect

Automatic cleaning function: By triggering the shape memory effect through temperature or stress, the filter screen undergoes deformation (such as aperture expansion or contraction) after blockage, using mechanical force to shake off or discharge impurities, achieving self-cleaning and reducing manual maintenance frequency.

Adaptive filtering accuracy: dynamically adjust the aperture size according to the fluid state. For example, maintaining small aperture high-precision filtration at low temperatures and expanding aperture to prevent clogging at high temperatures (suitable for temperature sensitive fluids).

2. Superelasticity and fatigue resistance

Impact resistance and long-term stability: It is not easily deformed under fluid impact, can withstand high-frequency vibration or pressure fluctuations, extend the service life of the filter, and is suitable for high-pressure and high flow rate gas-liquid filtration scenarios (such as industrial pipelines, aviation engine fuel filtration).

3 Corrosion resistance

Adapt to complex media: It has excellent corrosion resistance to acids, bases, salts, and high-temperature fluids (such as chemical solutions and steam), avoiding the corrosion problem of traditional metal filters (such as stainless steel), and is suitable for corrosive environments.

4. Processability and structural flexibility

Complex structure customization: Porous mesh, corrugated, spiral and other complex structures can be made through laser processing, 3D printing and other technologies to increase filtration area, optimize fluid distribution, and improve filtration efficiency.

2、 Design concept of nickel titanium memory alloy gas-liquid filter screen

1. Structural design

Multi stage composite filter screen:

Inner layer: Fine pore nickel titanium mesh, used for high-precision filtration;

Outer layer: Coarse aperture support structure provides mechanical strength and prevents deformation of the inner layer.

Dynamic deformation structure:

Ripple or folding filter screen, which triggers deformation through temperature/stress to change porosity (such as in the filtration of lubricating oil for automotive engines, dense filtration at low temperatures, and loose discharge at high temperatures).

Intelligent integrated design:

Linked with temperature sensors, the shape memory effect is triggered by electric heating (utilizing the resistance characteristics of nickel titanium alloy) to achieve automatic cleaning (such as periodic self-cleaning in steam pipeline filtration).

2. Working mode

Active cleaning mode: Regularly or when blocked, the filter screen is deformed by external stimuli (such as heating or pressure) to remove attached impurities.

Passive adaptive mode: Automatically adjust filtering accuracy based on fluid parameters (temperature, pressure) without external intervention.

3、 Key Technologies and Implementation Paths

1. Alloy composition and performance control

Optimize the nickel titanium ratio: Adjust the nickel content in Ni Ti alloy (usually 50%~55% atomic ratio), regulate the phase transition temperature (such as setting the austenite phase transition temperature to the normal working temperature of the fluid to ensure stable filtration state).

Surface treatment: By coating (such as diamond-like coating) or oxidation treatment, further enhance corrosion resistance and adhesion resistance, and reduce impurity retention.

2. Manufacturing process

3D printing technology: Using laser powder bed melting (LPBF) or electron beam melting (EBM) technology, filter screens with complex pore structures are manufactured, with precise control of pore size distribution (micrometer to millimeter).

Traditional processing and heat treatment: foil or wire materials are prepared through processes such as cold rolling and annealing, and then woven, stamped and formed, combined with aging heat treatment to optimize shape memory performance.

3. Self cleaning trigger mechanism

Temperature triggered: Utilizing the temperature changes of the fluid itself (such as steam condensation heat release) or external heating elements (such as resistance wires) to activate the shape memory effect.

Stress triggering: The deformation of the filter screen is driven by fluid pressure difference (such as an increase in upstream and downstream pressure difference when blocked, triggering hyperelastic deformation to expand the aperture).

4、 Exploration of application scenarios

1. Automotive industry

Engine fuel/lubricant filtration: automatically cleans in high and low temperature cycles to avoid impurities blocking the oil circuit and improve engine reliability.

Air filter: Utilizing super elasticity to resist car vibrations, extending the lifespan of the filter screen, and triggering cleaning through temperature to adapt to complex road conditions.

2. Chemical and petroleum industries

Corrosive medium filtration: When dealing with acid, alkali solutions or sulfur-containing oil and gas, traditional filter screens should be avoided from corrosion and damage, reducing the risk of leakage.

High temperature steam filtration: In refineries and chemical reactors, it can withstand high-temperature steam erosion and remove scaling particles through deformation.

3. Aerospace

Hydraulic system filtration: In aircraft hydraulic pipelines, anti fatigue characteristics are used to cope with high-frequency vibrations and prevent filter rupture from causing system failures.

Propellant filtration: In rocket engines, it can withstand extreme temperatures (such as liquid hydrogen/liquid oxygen environments) and achieve precise filtration at low temperatures and rapid impurity removal at high temperatures through shape memory effects.

4. Environmental Protection and Water Treatment

Industrial wastewater filtration: When treating wastewater containing heavy metal ions or particulate matter, the advantage of corrosion resistance is significant, and the self-cleaning function can reduce secondary pollution caused by chemical cleaning.

5、 Potential challenges and solutions

1. High cost

Solution: Optimize the alloy preparation process (such as using low-cost melting technology), or combine it with traditional materials (such as stainless steel), and only use nickel titanium alloy in critical parts (such as self-cleaning components).

2. High temperature performance limitations

The usage temperature of nickel titanium alloy is usually below 300 ℃, and the shape memory effect decays under high temperature environment.

Solution: Develop high-temperature memory alloys (such as nickel titanium niobium alloys) or use coating technology to isolate high-temperature fluids.

3. Impurity adhesion and cleaning efficiency

Viscous impurities (such as sludge) may be difficult to remove through simple deformation.

Solution: Combining ultrasound assisted, electrochemical activation and other composite cleaning technologies, or designing surface microstructures (such as nano textures) to reduce surface energy and adhesion.

4. Large scale production and consistency

The batch manufacturing of precision structures is difficult, and it is necessary to ensure that the performance of different batches of alloys is consistent.

Solution: Introduce automated production lines and control quality through online detection (such as differential scanning calorimetry to monitor phase transition temperature).

6、 Development prospects and suggestions

The application of nickel titanium memory alloy in the field of gas-liquid filtration is innovative and practical, especially suitable for extreme environments or intelligent scenarios that traditional materials cannot handle. In the future, the following tasks can be focused on:

1. Basic research: Conduct in-depth research on the interaction mechanism between alloys and fluid media, optimize structural design to improve filtration efficiency and self-cleaning effect.

2. Interdisciplinary integration: Combining sensors and microelectromechanical systems (MEMS) to achieve intelligent monitoring and adaptive adjustment of the filtering process.

3. Standard setting: Establish performance testing standards for nickel titanium alloy filters (such as filtration accuracy, fatigue life, cleaning efficiency, etc.) to promote industrial application.

Through technological breakthroughs and cost control, nickel titanium memory alloys are expected to form differentiated competitiveness in the high-end filtration field, providing a new path for the intelligence and efficiency of gas-liquid filtration.