WHAT IS

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Disclaimer: This Guide to Liquidmetal® is subject to change and update at any time without notice and any errors are subject to correction without liability.

Copyright: Liquidmetal Technologies, Inc. January 31, 2018

A GUIDE TO AMM TABLE OF CONTENTS

Chapter 1: INTRODUCTION TO AMORPHOUS METALS

Chapter 2: THE TECHNOLOGY & PROCESS TODAY• Company Introduction• The Beginning: From Crystal to BMGS

Chapter 3: HOW & WHY TO CHOOSE AMORPHOUS METALS

Chapter 4: DIMENSIONAL ACCURACY & REPEATABILITY• Recent Studies

Chapter 5: MATERIAL PROPERTIES

Chapter 6: CORROSION RESISTANCE & BIOCOMPATIBILITY• Salt Fog• Galvanic• Result Summary

Chapter 7: TECHNOLOGY COMPARISON

Chapter 8: NEXT STEPS

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THE COMPANYLiquidmetal Technologies provides advanced molding solutions for complex and high-performance metal parts. The company began on the foundation of amorphous metal technology, and has now expanded process capabilities to metal injection molding (MIM). Matching every customer application with the best process available is a focus at Liquidmetal. Because of this, customers benefit from a solid technical and economic solution.

INTRODUCTION

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INTRODUCTION TO AMORPHOUS METALSTHE BEGINNING: FROM CRYSTALS TO BMGSCenturies of technological advancement has led to hundreds of metal alloys, and until recently, each of them shared a common thread of a crystalline microstructure. Every crystalline alloy’s atoms arrange in naturally occurring patterns that represent the most stable form of the material.

These materials exhibit broad trends that limit what can be done with them. For example, a metal’s melting temperature is usually proportional to its hardness, and a material’s strength is usually inversely proportional to its ductility. This means that alloys with low melting points (which can be cast readily) are often soft and low-strength while alloys with high melting points (which cannot be cast easily) are often hard, brittle, and high-strength.

The fundamental innovations leading up to Liquidmetal’s amorphous metal technology date back to the early 1960s with the development of gold-silicon alloys that could be formed into a non-crystalline (also known as “amorphous”) microstructure at extremely high cooling rates. By designing alloy compositions around deep melting points (also called “eutectics”), the alloy could be cooled from the liquid state (where no crystal structure exists) to room temperature without forming a crystalline structure. By rapidly

cooling, one could trap the “liquid-like” microstructure into the non-crystalline (or “amorphous”) solid, creating a new class of metal alloys, which can be called amorphous.

Several decades of R&D proved it difficult to form amorphous metal parts thicker than a ribbon without crystal grain boundaries (the “weak regions” in crystalline materials). In 1990, with support from NASA, Caltech formulated Vitreloy, the first bulk metallic glass (BMG) with a thickness greater than 1mm.ter than 1mm.

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Alloy in Molten State

Amorphous Atomic

Structure

Ordinary Alloys Naturally Crystallize

CRYSTALLINE ATOMIC

STRUCTURE

AMORPHOUS ATOMIC

STRUCTURE

WEAK REGION

Chill Crystals Equiaxed GrainsColumnar Grains

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Figure 1.

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THE TECHNOLOGY &PROCESS TODAY Amorphous alloys as a scientific breakthrough now impact hundreds of applications and components across a wide range of markets. To engineers, metallurgists, scientists, and business professionals alike, interest comes from material properties that are nearly impossible to form in crystalline metals, with CNC-like complex precision molding. Now, as a production-ready, high volume manufacturing solution, amorphous metals represent a host of powerful material and manufacturing capabilities.

Two molding technologies exist for manufacturing amorphous alloy parts. The first is a cold-crucible process that produces very high purity alloys suitable for the medical and dental device, and implant markets. The second molding technology is a hot-crucible process that makes much larger parts with thinner walls in lower-cost alloys. The hot-crucible platform lends itself well to applications from a broad range of markets including automotive, consumer, electronics, industrial, and sporting equipment.

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COLD-CRUCIBLE HOT-CRUCIBLE

Platform Modified plastic injection molding Modified die cast

Heating Injection unit in to vacuum >1000ºC Crucible in vacuum to >1000ºC

Automation Fully automated continuous production Fully automated continuous production

Shot Size 100g shot size 300g shot size

Max Part Weight 80g shot size 180g shot size

Maximum dimension 100mm 200mm

Wall thickness 0.6mm-4.0mm 0.3mm-3.0mm

Table 1. A comparison of Liquidmetal's two AMM processing platforms.

THE TECHNOLOGY & PROCESS TODAY

INGOT Amorphous alloys begin as a crystalline ingot, and currently a maximum mass of 300 grams. The alloys are mainly composed of titanium and zirconium.

MELTING Using an induction coil, melting concludes when the material is molten at roughly 1000°C.

MOLDING Due to the nature of metal molding, and the materials minimal shrinkage, mold wear and durability is a primary focus.

REMOVAL Parts removed from the mold are in their final geometry, aside from gate and runner removal.

DEGATING Several cutting tools can be used to remove the gate and runner, depending on the precision required. Most often CNC-machining or waterjetting is required.

RECYCLINGThe Liquidmetal team takes steps to recycle material that is not used in material features, mainly gate and runner vestiages.

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The Liquidmetal molding process begins with crystalline material, which is automatically loaded into the machine for melting. Liquidmetal alloy ingots weighing up to 300 grams (depending on the process) are heated under vacuum to protect the alloys from unwanted contamination, such as exposure to oxygen. When the alloy is fully molten, the metal is injected under pressure into permanent steel molds similar to conventional plastic injection molds. Mold temperatures are controlled to cool and solidify the Liquidmetal alloy into final part geometries until the part is ready for ejection. By the time the part is ejected from the mold, it has achieved full material properties in this single-step molding process. Parts can be designed to include the same level of three-dimensional complexity as plastic injection molded parts.

Figure 2.

(Above) Liquidmetal headquarters in Lake Forest, CA.

(Left) ENGEL e-motion cold-crucible molding machine for processing amorphous alloys.

(Right) EONTEC hot-crucible machine for processing amorphous alloys.

HOW & WHY TO CHOOSE AMORPHOUS METALS

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HOW & WHY TO CHOOSE AMORPHOUS METALS When developing a new product design, designers of metal components must always consider the manufacturing methods available to them. At the same time, they must consider the geometric possibilities and material characteristic needs for the particular functional and performance requirements of the application for which they are designing. This is not always a simple task, as different manufacturing processes yield different results and costs. The Liquidmetal process is a combination of an unusual metal alloy with highly useful properties, and a shape forming process common to plastic components. This provides a new set of possibilities for metal parts fabrication and component designs not previously possible with other metal forming technologies.

The key capabilities of the Liquidmetal process are listed below:

• Exceptional dimensional control and repeatability

• Excellent corrosion resistance

• Brilliant surface finish

• High strength

• High elastic limit

• High hardness, scratch & wear resistance

• Non-magnetic

• Complex shapes that can be molded

If you need three or more of these characteristics, you likely have a Liquidmetal application.

MARKET APPLICATIONS

AutomotiveEngine timing systems, fuel injection, fuel rail components, small precision gears, passenger safety devices, pumps, pressure sensors, ABS system components, decorative interior and exterior components, severe duty connectors, ignition systems, variable valve components

Dental Tools, equipment, orthodontia brackets

Medical Devices

Broad range of device applications for actuation components, clamping, cutting, piercing, sealing, stapling, suturing

Medical Implants

ISO 10993 Biocompatibility testing has been completed successfully, including long-term animal implant studies.

IndustrialPressure sensors, compressor components, power tools, hand tools, small precision gears, severe duty connectors, mechanical assemblies, poppets, valves, pumps

Sporting Equipment

Archery, bicycling, firearms, fishing reels, knives, recreational tools, scuba equipment

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Table 2.

DIMENSIONAL ACCURACY & REPEATABILITYThe Liquidmetal® amorphous metal process can achieve dimensional accuracy and repeatability results that are usually only common to production CNC (Computer Numerical Control) machining processes, but at a much lower cost. Today, designers can expect dimensional accuracy and repeatability of ±0.08% of a given part dimension.

Liquidmetal alloy solidifies during the molding process nearly isotropically, so design sensitivities to the 0.4% solidification shrinkage of the material and dimensional tolerances of part features are insignificant.

Freezing incompressible molten metal during the molding process without changes to the atomic structure of the material plays a significant role in the resulting dimensional accuracy and repeatability of the process. This highly unique aspect of dimensional control is not inherent to any other metalworking technology. Furthermore, high-performance material properties are achieved without any post-molding heat-treating or annealing requirements that are common with other crystalline metal alloys. This benefit avoids further loss of dimensional control from residual stress, part warpage, distortion, or growth with many heat treating processes used by conventional crystalline metal alloys.

DIMENSION METRIC ENGLISH

±0.0203mm for dimensions up to 25.4mm ±0.0008” for dimensions up to 1.0”

±0.0203mm for each additional 25.4mm ±0.0008” for each additional 1.0”

±0.05mm for dimensions up to 25.4mm ±0.002” for dimensions up to 1.0”

±0.025mm for each additional 25.4mm ±0.001” for each additional 1.0”

Flatness 0.05mm 0.002”

Straightness 0.05mm 0.002”

Angularity 0.001mm/mm 0.0004” in/in

Concentricity 0.05mm (// to parting line) 0.002” (// to parting line)

Circularity 0.05mm (// to parting line) 0.002” (// to parting line)

Table 3. This chart displays typical tolerances for as-molded Liquidmetal parts. Please note the two categories of linear features.

Critical to FunctionLinear Features

Non-Critical/StandardLinear Features

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DIMENSIONAL ACCURACY & REPEATABILITY

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RECENT STUDIESIn a recent study, a total of 128 parts (32 per cavity), which can be seen on the back cover of this paper, from a four cavity sales sample mold were inspected. The four measurements are plotted below.

Each cavity plot includes the calculated six-sigma capability of that cavity. Additionally, the combined six sigma capability across all four cavities (128 parts) was calculated and plotted. The colored lines in each of the following four charts represents the individual cavities and the solid black line represents the combined six sigma plot for all four cavities.

Along with the tables cavity(s) displayed, note the summary capability data from this study as well. As you can see from the data, the Liquidmetal process provides significantly high levels of precision and repeatability, far better than many other metal forming technologies. The specifications for this component are very narrow and are even more challenging when asked to comply with them within a Six Sigma capability.

More information, including flatness data from this study is displayed in our Design Guide available for download at Liquidmetal.com.

Figure 3.

HOT CRUCIBLE

INJ-LM105

COLD CRUCIBLE

CO

MPR

ESSI

VE

GEN

ERA

LTE

NSI

LE

COMPOSITION Zirconium based alloy Zirconium based alloy

DENSITY, ρ

g/cm 3 6.68 6.72

(lb/in 3) 0.241 0.243

HARDNESS

Vickers 563 530

Rockwell C 53 51

CHARPY IMPACT

J/m 2 3.5

FATIGUE STRENGTH

MPa @ 10 7 cycles 304 206

(ksi @ 10 7 cycles) 44.1 29.8

SPECIFIC STRENGTH, s/r

MPa•cm 3/g 228 184

(ksi•in 3/lb) 917 897

POISSON’S RATIO, ν

0.38

ELASTICITY, e

(% of Original Shape) 1.80% 1.6%

ULTIMATE TENSILE STRENGTH

MPa 1524 1236

(ksi) 221 179

YOUNG’S MODULUS, E

GPa 92.7 75

ULTIMATE STRENGTH

MPa 1890

(ksi) 274

ELASTIC STRAIN

(% of Original Shape) 2.3%

MODULUS

GPa 86.5

DC-106c

MATERIAL PROPERTIES Liquidmetal® alloy has a distinctive combination of mechanical, thermal, environmental, and other physical properties due to its amorphous atomic microstructure. These properties should underpin the decision by designers and engineers to successfully apply Liquidmetal alloys to particular applications.

It is important to note that amorphous alloy properties are set after molding. Amorphous components cannot be treated, processed or changed due to their reliance on the random atomic structure.

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Table 4.

MATERIAL PROPERTIES

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ELEC

TRIC

AL

& S

URF

AC

E

HOT CRUCIBLE

INJ-LM105

COLDCRUCIBLE

DC-106c

FLEX

UR

AL

THER

MA

LBI

O &

EN

VIR

ON

MEN

TAL

ULTIMATE STRENGTH

MPa 2096 ~2000

(ksi) 304 ~290

ELASTIC STRAIN

(% of Original Shape) 1.73%

TANGENT MODULUS OF ELASTICITY

GPa 101.7 80.0

GLASS TRANSITION TEMPERATURE, Tg

°C 399 407

°F 750 765

CRYSTALLIZATION TEMPERATURE, Tx

°C 468 489

°F 874 912

SOLIDUS TEMPERATURE

°C 785 820

°F 1445 1508

LIQUIDUS TEMPERATURE

°C 858 841

°F 1576 1546

THERMAL CONDUCTIVITY

W/m•K ~5 ~5

STD. OPERATING TEMPERATURE

°C <250 <250

°F <482 <482

SALT SPRAY (ASTM B117)

After 336 hoursNo detectable degradation at

330 hoursTBA

SEAWATER IMMERSION

After 30 days No detectable degradation

RESISTANCE TO ACIDITY Yes Yes

RESISTANCE TO ALKALINITY Yes Yes

BIOCOMPATIBILITY

Toxicity, Irritation, Sensitization, Systemic Toxicity, Hemocompatibility

Pass TBD

Mutagenicity, Pyrogenicity Pass TBD

SURFACE FINISH Functional and Cosmetic Functional and Cosmetic

Type As-cast, Blasted, Polished As-cast, Blasted, Polished

ROUGHNESS, Ra

μm 0.05 0.05

μin 2 2

ELECTRICAL RESISTIVITY, r

μΩ.cm 160

μΩ.in 63

Table 4. Cont.

Amorphous metal parts colored with multiple surface treatment processes: PVD, conversion coating, anodization, e-coating, oxidization and more.

(Right) Two amorphous metal parts demonstrating the material's nearly-optical surface finish.

(Below) Amorphous Metalsparts cooling on a conveyor belt.

CORROSION RESISTANCE & BIOCOMPATIBILITY

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CORROSION RESISTANCE &BIOCOMPATIBILITYLiquidmetal® amorphous alloys are highly corrosion resistant. Even when exposed to harsh conditions, they perform very well compared to other traditional alloys normally selected for corrosion resistant applications. In addition to several biocompatibility studies that have been completed, salt fog and galvanic corrosion tests have been conducted.

SALT FOG• ASTM B117 standard ranks LM105 as good as the best crystalline alloys.

• Liquidmetal amorphous alloys can be repassivated after bead blasting for medical applications.

• Bead blasted and passivated surfaces of INJ-LM105 in salt fog environments after 336 hours, show no signs of staining.

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SS-316

TOTAL DISSOLUTION CONCENTRATION (PPM)

1N HCl

250500

1N H2 SO4 NaOH pH13 Seawater

0 0

3600

100 0 0

Figure 4.

RESULT SUMMARYLiquidmetal’s® amorphous alloy LM105 has recently undergone several ISO-10993 biocompatibility tests, including long term implant studies to ensure the material is suitable for use in medical devices. These successful test results are important to LM105’s success in offering solutions to a broad range of potential applications.

The following chart and information summarize LM105’s compatibility with devices used in the body or in contact with the body. The results show that this amorphous alloy is a potential candidate for three types of biomedical devices:

• Surface devices on the skin, mucosal membranes, etc.

• External communicating devices with blood, tissue, bone, dentin.

• Short and long term implantable devices.

TEST RESULT

ISO 10993

Cytotoxicity

Sensitization

Irritation or Intracutaneous Reactivity

Systemic Toxicity (acute)

Hemocompatibility

Pass (Non-cytotoxic)

Pass (Non-sensitizing)

Pass (Non-irritating)

Pass (Non-systemic-toxic)

Pass (Non-hemolytic)

Implantation Tests

Genotoxicity

Implantation

Systemic Toxicity

• Materials Mediated Pyrogenicity • Subchronic Toxicity Test

Pass (Non-mutagenic)

Pass (Non-irritating)

Pass (Non-pyrogenetic)Pass (Within Normal Limits)

Nickel Release

• As-molded• Blasted and Passivated

PassPass

Anti-Microbial Study Testing Underway

GALVANICGalvanic corrosion occurs when dissimilar metals preferentially corrode when in contact with each other. In general, amorphous alloys perform well in galvanic testing.

• These favorable results are significant because they show limited risk of galvanic corrosion in medical device assemblies which incorporate Liquidmetal components in contact with other metals.

• The graphic below displays as-molded 75x25x1mm LM105 plates that were paired with different medical grade alloys (top column) in a [30 days, 65C] saline galvanic test.

LEAST RESISTANT MOST RESISTANT

Al 7075 SS 17-4PH SS 304 SS 301 SS 316 Ti (grade 2) Ti (grade 5) LM105

LM105 LM105 LM105 LM105 LM105 LM105 LM105 LM105

Figure 5.

Table 5.

(Right) A three-point bend test demonstrates the high elastic limit of Liquidmetal alloys. The 0.85mm thick plate is under approximately 1.5% strain and returns to its exact original as-molded size and shape when the load is released. Since the entire elastic region is within the proportional limit, all stress-strain responses are linear and the original geometry is fully recoverable up to 1.8% strain. 17

(Right) Amorphous metal molding yields precise, complex shapes, including gears manufactured to AGMA quality standard no. 11.

(Left) AMM's one-step molding process yields complex geometries that may not be possible to form in an economically sensitive way with traditional processes.

TECHNOLOGY COMPARISONThere is no single perfect technology solution for all applications. As new products continually evolve and develop, both proven and leading-edge technologies should be considered and evaluated for performance, quality, and cost objectives. The Liquidmetal amorphous metal process provides a unique set of application characteristics that differentiate it from other manufacturing technologies. Table 6 compares the core strengths of the Liquidmetal process against other popular metalworking technologies.

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Table 6. Comparison of the Liquidmetal process and various other metalworking technologies.

See table 3. for more detail on dimensional tolerance of Liquidmetal parts.

LIQUIDMETAL DIE CASTING MIM INVESTMENT

CASTING MACHINING

Low Cost/High Part Complexity

YES Yes Yes No No

Fine Surface Finish <2.0 Ra (Micro Inches) Without Secondary Operations

YES No No No Yes

High Elastic Limit YES No No No No

Single Process Step YES No No No No

No Heat Treating Required to Achieve High Hardness

YES No No No No

No Heat Treating Required to Achieve High Strength

YES No No No No

Low Process Scrap YES Yes Yes No No

Tolerance Control (% of feature size)

+/- 0.08 +/- 0.4 +/- 0.3 +/- 0.5 +/- 0.08

NEXT STEPS

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NEXT STEPS The Liquidmetal team focuses on your success. Identifying a solid technical and economical solution for your application is our goal. Providing Design for Manufacturing (DFM) and in-house analytical and inspection services ensure the best part designs and processes are used.

To help you make a confident decision regarding your application, transparency and education is our goal. Liquidmetal offers a range of materials covering detailed and general subjects surrounding our technology:

• Design Guide

• Case studies

• Webinars

• Videos

Each item is free for attendance or download at liquidmetal.com. In Design Guide 4.2 you will find more details on topics covered in this guide, including dimensional precision and control, and material properties like reflectivity, magnetism, and surface finish. Part design guidelines are also featured: draft requirements, wall thickness, radii & fillets, holes & slots, threads, surface features & texturing, molding behavior & part aesthetics, ejection, undercuts, overmolding, and post processing alternatives.

I encourage you to reach out with information on your part for quoting, any questions you may have, or a request for more information. An Application Specialist will follow up with you within a day to help you make your project a success.

Sincerely,

Kris Kent

Vice President, Sales and Marketing

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Liquidmetal® Technologies – Corporate20321 Valencia Circle, Lake Forest, CA 92630

949.635.2100 • www.liquidmetal.com