Solder & Low-Melting Alloy In97Ag3
In97Ag3 is a high-indium solder alloy with 3% silver, melting at about 143 °C and supplied as wire, foil, preform, ingot and paste.
Reference datasheet — In97Ag3 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
What is In97Ag3?
In97Ag3 is a high-indium solder alloy with 3% silver, melting at about 143 °C and supplied as wire, foil, preform, ingot and paste. It is chosen for excellent wetting on gold and glass, retained ductility at cryogenic temperatures and low-stress joints in optoelectronic and vacuum hardware; typical values are 6 MPa tensile strength, 55% elongation and 1.2 HB. Strength is very low and service is limited to about 60 °C, and indium cost is high; pure In100 is the nearest alternative when a slightly higher melt point and no silver are acceptable. In97Ag3 has a density of 7.38 g/cm³ (0.267 lb/in³), lighter than 74% of solder & low-melting alloy grades. It melts at 143°C (289 °F). In97Ag3 has a yield strength of 3 MPa (0.435 ksi) and a tensile strength of 6 MPa (0.87 ksi) — weaker than 99% of solder & low-melting alloy grades. Elongation at break is 55% and the elastic modulus is 11 GPa (1.6 Msi).
What is In97Ag3 used for?
- optoelectronic die attach
- cryogenic sealing
- vacuum feedthrough soldering
- gold-metallized component bonding
Advantages
- Conducts heat well — 73 W/m·K (42.2 BTU/hr·ft·°F), better than 99% of solder & low-melting alloy grades
- High electrical conductivity — 18 % IACS, better than 99% of solder & low-melting alloy grades
- Ductile — tolerates forming and impact — 55%, better than 96% of solder & low-melting alloy grades
Limitations
- Difficult to machine — 8/100, worse than 100% of solder & low-melting alloy grades
- Low strength — 3 MPa (0.435 ksi), worse than 99% of solder & low-melting alloy grades
- Hard to polish — 15/100, worse than 99% of solder & low-melting alloy grades
- High embodied carbon — 110 kg CO₂/kg, worse than 99% of solder & low-melting alloy grades
- Low stiffness — 11 GPa (1.6 Msi), worse than 96% of solder & low-melting alloy grades
In97Ag3 properties
Typical room-temperature values; bars are the position among solder & low-melting alloy grades.
Physical3
In97Ag3 has a density of 7.38 g/cm³ (0.267 lb/in³), lighter than 74% of solder & low-melting alloy grades. It melts at 143°C (289 °F).
Mechanical9
In97Ag3 has a yield strength of 3 MPa (0.435 ksi) and a tensile strength of 6 MPa (0.87 ksi) — weaker than 99% of solder & low-melting alloy grades. Elongation at break is 55% and the elastic modulus is 11 GPa (1.6 Msi).
Thermal6
In97Ag3 is rated for continuous service to 60°C (140 °F). It conducts heat at 73 W/m·K (42.2 BTU/hr·ft·°F), better than 99% of solder & low-melting alloy grades. Thermal expansion is 30 µm/m·K (16.7 µin/in·°F).
Electrical3
In97Ag3 conducts electricity at 18 % IACS, better than 99% of solder & low-melting alloy grades.
Chemical & Environmental2
Corrosion resistance is fair (45/100), worse than 52% of solder & low-melting alloy grades.
Sustainability3
Producing a kilogram of In97Ag3 takes about 1,800 MJ of energy and emits 110 kg of CO₂ — more than 99% of solder & low-melting alloy grades. Typical recycled content is 35%.
Manufacturability6
In97Ag3's machinability is not recommended (8/100, worse than 100% of solder & low-melting alloy grades); weldability poor (25/100); formability excellent (98/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the solder & low-melting alloy family
Yield strength against density for every solder & low-melting alloy grade FabDigit runs. In97Ag3 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with In97Ag3
Is In97Ag3 easy to machine?
Essentially unmachinable by conventional cutting — the alloy smears, welds to tools and self-anneals; shear, stamp, roll or die-cut instead, ideally chilled.
Can In97Ag3 be welded?
Not fusion welded; joined by reflow or hand soldering at 165–200 °C with mildly activated or no-clean flux, keeping time above liquidus short to limit Au dissolution.
Can In97Ag3 be formed, bent or molded?
Cold rolls and extrudes to foil, ribbon and wire with almost unlimited ductility; it recrystallizes at room temperature so work hardening does not accumulate.
In97Ag3 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Ageutectic composition with In | 2.5 – 3.5 | 3 |
| Pbimpurity limit, RoHS-compliant grades | ≤ 0.02 | |
| Cdimpurity limit | ≤ 0 | |
| Cuimpurity limit | ≤ 0.02 | |
| Feimpurity limit | ≤ 0.02 | |
| Znimpurity limit | ≤ 0.01 | |
| Intypically 99.99% grade indium base | balance |
What surface finishes work on In97Ag3?
No plating or anodizing is applied; store in dry, sulfur-free packaging, degrease before use and avoid contact with mercury or bare aluminium.
How much does In97Ag3 cost?
In97Ag3 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
In97Ag3 — frequently asked
What is In97Ag3 used for?
In97Ag3 is typically used for optoelectronic die attach, cryogenic sealing, vacuum feedthrough soldering and gold-metallized component bonding. In short: wets gold and glass; ductile at cryogenic temperature; low-stress die-attach solder.
What is the yield strength of In97Ag3?
In97Ag3 has a typical yield strength of 3 MPa (0.435 ksi) and a tensile strength of 6 MPa (0.87 ksi) — weaker than 99% of solder & low-melting alloy grades.
Is In97Ag3 easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 100% of solder & low-melting alloy grades). Essentially unmachinable by conventional cutting — the alloy smears, welds to tools and self-anneals; shear, stamp, roll or die-cut instead, ideally chilled.
Can In97Ag3 be welded?
Not readily — weldability is rated poor (25/100). Not fusion welded; joined by reflow or hand soldering at 165–200 °C with mildly activated or no-clean flux, keeping time above liquidus short to limit Au dissolution.
What surface finishes work on In97Ag3?
No plating or anodizing is applied; store in dry, sulfur-free packaging, degrease before use and avoid contact with mercury or bare aluminium.
Can In97Ag3 be formed, bent or molded?
Cold rolls and extrudes to foil, ribbon and wire with almost unlimited ductility; it recrystallizes at room temperature so work hardening does not accumulate.
What is the maximum service temperature of In97Ag3?
In97Ag3 is rated for continuous use to about 60°C (140 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does In97Ag3 cost?
In97Ag3 is a high-cost solder & low-melting alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- Indium Alloy Data Sheet — 97In/3Ag — Indium Corporation (2023)
- J-STD-006 Requirements for Electronic Grade Solder Alloys — IPC/JEDEC (2013)
- ASM Handbook Vol.3: Alloy Phase Diagrams (Ag-In system) — ASM International (2016)
- CRC Handbook of Chemistry and Physics — properties of indium — CRC Press (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.