Ni-Mn-Ga Magnetic Shape Memory Alloy (MSM),Ni50Mn28.5Ga21.5 single crystal.，1

### **Ni-Mn-Ga Magnetic Shape Memory Alloy (MSMA) - Ni₅₀Mn₂₈.₅Ga₂₁.₅ Single Crystal** #### **Overview** **Ni-Mn-Ga Magnetic Shape Memory Alloys** represent a groundbreaking class of smart materials that exhibit large, reversible strains when exposed to magnetic fields. The **Ni₅₀Mn₂₈.₅Ga₂₁.₅ single crystal** composition is particularly notable for achieving exceptional magnetic field-induced strain (MFIS) through martensitic variant reorientation. Unlike conventional shape memory alloys activated by temperature changes, these materials respond to magnetic stimuli, enabling rapid, contactless actuation with frequencies up to several hundred hertz. --- #### **Chemical Composition (Atomic %)** | Element | Content (at.%) | Tolerance | Function | |---------|---------------|-----------|-----------| | **Nickel (Ni)** | **49.5-50.5%** | **±0.5%** | Primary matrix element, controls phase stability | | **Manganese (Mn)** | **28.0-29.0%** | **±0.5%** | Magnetic moment carrier, influences Curie temperature | | **Gallium (Ga)** | **20.5-22.5%** | **±1.0%** | Stabilizes martensitic phase, modifies transformation temperatures | *Note: Composition control is critical as ±0.1% variation can shift transformation temperatures by 10-20K.* --- #### **Physical & Functional Properties** | Property | Value / Description | |----------|---------------------| | **Density** | **8.20-8.35 g/cm³** | | **Melting Point** | **~1150-1200°C** | | **Crystal Structure** | **5M/7M modulated martensite** (at room temperature) | | **Magnetic Field-Induced Strain** | **5-10%** (depending on martensite variant) | | **Response Frequency** | **Up to 500 Hz** | | **Blocking Stress** | **3-8 MPa** | | **Young's Modulus** | **1-5 GPa** (anisotropic, variant-dependent) | | **Curie Temperature** | **370-380 K** (~97-107°C) | | **Martensitic Start (Ms)** | **300-320 K** (~27-47°C) | | **Magnetic Saturation** | **70-80 emu/g** | | **Coercivity** | **10-50 mT** | --- #### **Key Characteristics & Applications** **Key Characteristics:** - **Giant Magnetic Field-Induced Strain**: Up to 10% reversible strain under magnetic fields - **Fast Response**: Millisecond-scale actuation capability - **Contactless Actuation**: Enabled by magnetic field control - **High Work Density**: ~10⁵ J/m³, superior to piezoelectric materials - **Two-Way Shape Memory Effect**: Reversible without external stress - **Temperature-Magnetic Coupling**: Multifunctional response capabilities **Typical Applications:** - **Precision Positioning Systems**: Micro-positioners, optical beam steering - **Active Vibration Control**: Dampers for aerospace and automotive systems - **Microfluidic Systems**: Pumps and valves for lab-on-chip devices - **Robotics**: Artificial muscles and compact actuators - **Energy Harvesting**: Vibration-to-electricity conversion devices - **Medical Devices**: Miniature surgical tools and implants - **Adaptive Structures**: Morphing wings, deployable structures --- #### **Manufacturing & Single Crystal Growth** **Growth Methods:** - **Bridgman Technique**: Most common for high-quality single crystals - **Floating Zone Method**: For high-purity crystals - **Czochralski Method**: Alternative approach **Processing Challenges:** - **Composition Homogeneity**: Critical for consistent properties - **Crystal Defects**: Affects variant rearrangement and strain output - **Orientation Control**: Specific crystal directions optimize performance - **Surface Quality**: Important for practical applications --- #### **International Standards & Research Status** | Category | Status | Notes | |----------|---------|-------| | **ASTM Standards** | **Under Development** | ASTM F2004-17 covers terminology | | **ISO Standards** | **Research Phase** | No specific MSMA standards yet | | **Material Characterization** | **Well-Established** | Academic protocols widely used | | **Quality Control** | **Laboratory Level** | University and research institute methods | *Note: Standardization efforts are ongoing through research consortia and professional organizations.* --- #### **Performance Comparison** | Material | Maximum Strain | Frequency | Work Density | Activation Method | |----------|----------------|-----------|--------------|-------------------| | **Ni-Mn-Ga MSMA** | **5-10%** | **~500 Hz** | **~10⁵ J/m³** | **Magnetic Field** | | **Ni-Ti SMA** | **6-8%** | **~10 Hz** | **~10⁶ J/m³** | **Temperature** | | **Piezoelectric** | **0.1-0.2%** | **~kHz** | **~10⁴ J/m³** | **Electric Field** | | **Magnetostrictive** | **0.1-0.2%** | **~kHz** | **~10⁴ J/m³** | **Magnetic Field** | --- #### **Current Research & Development** **Focus Areas:** - **Strain Optimization**: Achieving consistent 10+% strain - **Frequency Enhancement**: Extending operational bandwidth - **Polycrystalline Development**: Overcoming single crystal limitations - **Composite Materials**: Integrating with other functional materials - **Industrial Scaling**: Moving from laboratory to commercial production --- #### **Summary** **Ni₅₀Mn₂₈.₅Ga₂₁.₅ single crystal** represents the state-of-the-art in magnetic shape memory technology, offering unprecedented magnetic field-induced strains that surpass conventional actuation materials. While currently primarily in research and specialized applications, its unique combination of large strains, fast response, and contactless activation makes it a promising candidate for next-generation smart material systems. The ongoing development of manufacturing processes, standardization efforts, and application engineering continues to bridge the gap between laboratory demonstration and practical implementation. As understanding of these complex materials deepens and production challenges are overcome, Ni-Mn-Ga MSMAs are poised to enable transformative advances across multiple engineering disciplines, particularly in areas requiring compact, high-speed, and precise actuation capabilities.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3238 gallon liquid totes Special package is available on request.