Asif akbari bem711 transparent aluminium

About Transparent Aluminum (An Emerging Material)

1. TRANSPARENT ALUMINIUM Aluminium Oxynitride ( An Advanced Polycrystalline Transparent Ceramic) Commercially available as ALON® MD ASIF AKBARI, B.Tech (Civil) Ex-Engineer, RITES LTD ( A GOI Undertaking, Ministry of Railways) An Aligarh Muslim University Alumnus [phone] https://www.linkedin.com/in/akbariasif12

2. Advantages Transparent : High optical transmission (>85%) near-UV to mid-IR wavelengths (0.25to4.0μm). Crystal Clear : Excellent clarity and no inherent birefringence. Very high refractive index homogeneity over large areas. Durable : Outstanding hardness, scratch resistance, chemical resistance and high strength. Commercially Available : Large 18x35-in windows as well as shapes including hyper-hemispherical, ogive and hemispherical domes are available. Robust Process : Enables manufacturer to reliably manufacture and supply components of consistently high quality. MD ASIF AKBARI SPA/BEM/711

3. What is this? It is crystal-clear and ultra-hard advanced transparent ceramic material that is manufactured via powder processing. It has been fielded in many defense systems and is available commercially in large sizes and quantities. is the best transparent ceramic armor there is and the material of choice for ultra high resolution reconnaissance windows. Transparent aluminum, also known as aluminum oxynitride, is a transparent polycrystalline ceramic with a cubic spinel crystal structure made of nitrogen, oxygen and aluminum. Domes, tubes, transparent windows, rods and plates can be produced from this material using conventional ceramic powder processing methods. Methods for manufacturing transparent aluminum remain refined. The cost of this material is similar to that of synthetic sapphire. MD ASIF AKBARI SPA/BEM/711

4. Material Composition It is basically made up of MgAl 2 O 4 Linear Formula:  (AlN) x  • (Al 2 O 3 ) 1-x Aluminium oxynitride ( AlON ) is a transparent ceramic composed of aluminium , oxygen and nitrogen. (such as varying the aluminium content from about 30% to 36%, which hasbeen reported to affect the bulk and shear moduli by only 1–2%.) Synonyms - aluminum oxynitride, ALON, Al23O27N5,  aluminum oxynitride, transparent alumina,  aluminum oxynitride powder, ALON powder, spinel, CAS# 12633-97-5 Typical chemistries available (99.0%, 99.9%, 99.99% and 99.999%) Chemical Specification 99% Aluminum Oxynitride 99.9% Aluminum Oxynitride 99.99% Aluminum Oxynitride 99.999% Aluminum Oxynitride MD ASIF AKBARI SPA/BEM/711

5. Manufacturing Process MD ASIF AKBARI SPA/BEM/711

6. Manufacturing Process Transparent aluminum starts out as a pile of white aluminum oxynitride powder. That powder gets packed into a rubber mold in the rough shape of the desired part, and subjected to a procedure called  isostatic pressing , in which the mold is compressed in a tank of hydraulic fluid to 15,000 psi, which mashes the AlON into a grainy “green body.” The grainy structure is then fused together by heating at 2000 °C for several days. The surface of the resulting part is cloudy, and has to be mechanically polished to make it optically clear. MD ASIF AKBARI SPA/BEM/711

7. Physical Properties It is optically transparent in the near ultraviolet, visible and infrared regions. It is four times harder than fused silica glass, 85% harder than sapphire and 15% harder than magnesium aluminate spinel. The material remains solid up to 1200°C (2190°F). It has good corrosion resistance and resistance to damage from radiation and oxidation. It is about three times harder than steel of the same thickness. PROPERTIES VALUES Compressive strength 2.68 GPa Flexural strength 0.380.7 Gpa Fracture toughness 2 MPa.m Knoop hardness 1800 kg/mm Poisson ratio 0.24 Shear modulus 135 GPa Young modulus 334 GPa MD ASIF AKBARI SPA/BEM/711

8. Chemical Properties Typical chemistries available (99.0%, 99.9%, 99.99% and 99.999%) Chemical Formulae Al23-1/3XO27+XN5-X (0.429 < X < 2) Crystal Structure Cubic, Spinel   Form Polycrystalline   Chemical Resistant(Yes/No) HFAcid Yes Fluorine Plasma Yes Extreme Weather Yes Sea/SaltWater Yes Cryogenic Temperatures Yes MD ASIF AKBARI SPA/BEM/711

9. Optical Properties Transmission range (>80%) ~0.22 – 4.5 micron Refractive index Index of Refraction l(m m)                       n 0.48 1.803 0.50 1.801 0.64 1.790 0.68 1.788 0.70 1.787 1.00 1.779 2.00 1.761 3.00 1.737 4.00 1.702 5.00 1.653       Typical Haze <3% Typical Clarity >95% Typical RI inhomogeneity 5ppm over 11-inch dia aperture MD ASIF AKBARI SPA/BEM/711

10. Optical Properties (Continued) MD ASIF AKBARI SPA/BEM/711

11. Electrical Properties Volume resistivity$ (ohm-cm) >1014 Dielectric Constant f (GHz)        k 35-45 9.19 55-60 9.18 90-110 9.17 Loss Tangent ( tan d , x10-5) f (GHz)   tan d 35-45 31 55-60 67 90-110 96 Dielectric Strength (kV/mm) ~23 MD ASIF AKBARI SPA/BEM/711

12. Thermal Properties Melting Point (0C) 2,150 Thermal Conductivity (W/mK) ~13 Coefficient of Thermal Expansion (x10-6) 7.50 (30-900oC) Specific Heat (cal/g-oC) 0.22 Max. Usable Temperature (inert atm.) 1,900oC MD ASIF AKBARI SPA/BEM/711

13. Thermal Properties (Continued) PROPERTY Γ- ALON UNIT Refractive index (at wavelength 0.5 μm )6 1.8   dn /dT (in 3–5 μm wavelength range)6 3 10–6 K–1 Absorption coefficient (at 3.39 μm wavelength)6 0.1 cm–1 Total integrated optical scatter (at 0.64 μm ; ~5 mm thick sample)6 2.1 % Transmission wavelength range* 0.22–6 μ m Optical homogeneity achieved in 15 in. 3 25 in. part with ~5 ppm 3.4 in. aperture     Typical transmittance without AR coatings (in the visible range)* >84 % Typical haze (in the visible range)* <2 % Typical clarity (in the visible range)* >98 % MD ASIF AKBARI SPA/BEM/711

14. Ballistic resistant & Biological P roperties STANAG 4569 Level, 3-shots 1 2 3 50calAP 1 shot Areal density, kg/sq.m. 57 69 130 83 Thickness, mm 31 37 59 41 Non-toxic and Biocompatible - (Based on in vitro cell biology test results and in vivo test results in a rat distal femur model) Better Wear Resistance than Alumina in DMEMcell media (Wear rate: 1.845 ±0.428 (x10-6mm3 N-1 m−1) –1000m with 10N load) STANAG LEVEL-3 as per NATO MD ASIF AKBARI SPA/BEM/711

15. Durability Glass-based systems tend to degrade due to non-ballistic phenomena such as strikes, sand erosion and prolonged UV exposure. These conditions can quickly impair the clarity and function of glass-based transparent system. ALON® transparent aluminium , however, has proven to be exceptionally resistant to such conditions. Rock-Proof : Kicked up rocks and large debris can cause significant damage to glass-based transparent armor windows; however, at the same size and thickness, Surmet's ALON® ceramic can withstand granite rock strikes at over 4x the impact force required to shatter glass. Scratch-Proof: The optical transmission of glass-based transparent armor tends to degrade over time, due to thousands of tiny scratched made by wind-swept sand and dust. In controlled sand erosion testing, the optical transmission of glass-based armor reduced by 23% while the optical transmission of ALON® transparent armor remained the same. MD ASIF AKBARI SPA/BEM/711

16. Durability (continued) Delamination Resistant: ALON® transparent armor has low interlaminar residual stresses due to the compatible coefficient of thermal expansion (CTE) with both glass and polycarbonate. Under thermal cycling, ALON® transparent armor has a much lower propensity for delamination than glass-based armor. Tolerant of Extreme Conditions: ALON® transparent armor is an exceptionally high-performing material in extreme environmental conditions. ALON® transparent armor has proven to withstand both mechanical stresses (vibration, mechanical shock, g-loading and sudden pressure release) and environmental stresses (solar radiation, humidity, temperature ranges from +185°F to -67°F and thermal cycling). MD ASIF AKBARI SPA/BEM/711

17. Perfor mance Requirement Direct Fire and Blast Protection ALON is three times harder than glass, and therefore breaks up and erodes the projectile much more efficiently. The projectile debris is captured by the polycarbonate backing. Superior Ballistic Performance: Ballistic testing conducted at the Army Research Labs in Aberdeen, MD compared current glass based transparent armor to armor based on three transparent ceramic materials: ALON, Spinel and Sapphire. Surmet's ALON® ceramic performed 10% better than Spinel armor and 20% better than Sapphire armor — and 250% better than conventional glass based armor . Increased Window Size: To provide protection over extra large apertures, Surmet has developed tiled ALON® transparent armor. The tiled armor employs specially engineered seams that are virtually invisible to the viewer. Excellent Multi-Hit Performance: Tiled ALON® armor has successfully defended against a variety of multi-hit threats including 30calAPM2 rounds and 50calAPM2 rounds. In each test, ALON® transparent armor easily defeated the given threat. MD ASIF AKBARI SPA/BEM/711

18. Inspection and testing procedures Weibull modulus and characteristic strength Weibull modulus and characteristic strength were determined by fitting the measured data to a standard two parameter Weibull distribution given by Equation 1, ASTM C 1239-94a. Test fixture used for the biaxial flexure strength Grafoil ™ discs having a thickness of 0.005” thick were placed between the sample disc and the load and support rings to reduce the contact stresses that are thought to cause some samples to fail under the loading ring or support ring. The loading rate used was 0.02”/min for all measurements; Humidity 50%; Temperature 21° C and 500 °C MD ASIF AKBARI SPA/BEM/711

19. Inspection and testing procedures Sample Size and Test Fixture Dimensions Test Period Sample Diameter Sample Thickness Load Ring Diameter Support Diameter (Historical ) Raytheon 2002 0.998” 0.051” 0.4500” 0.9000” (Surmet) May 2004 0.994” 0.055” 0.4166” 0.8330” (Surmet) October 2004 1.244” 0.055” 0.4166” 0.8330” MD ASIF AKBARI SPA/BEM/711

20. Inspection and testing procedures Elastic Properties Measurements The elastic properties of Transparent Aluminium were measured according to ASTM C1259-01 using the same disc specimens (1.25” diameter x 0.055” thick) used for biaxial flexure testing. Test specimens in all three set of measurements were 100% dense transparent Aluminium Oxynitride. The difference may be in the due to the greater accuracy of the flexural resonance method used in the current measurements. Value UDRI (2004) Historical*(ref 4,5,6 ) SORI (1988) Historical*(ref 7) Raytheon (1984) Young’s Modulus , E (GPa) 321.05 321.3 323.8 Shear Modulus, G (GPa) 127.35 124.55 130.24 Poisson’s Ration , υ 0.26 0.24 0.24 * Historical (1988 and 1984) Data Measured in four point flexure using strain gages. Room Temperature Elastic Properties (E, G and υ) of ALON MD ASIF AKBARI SPA/BEM/711

21. Inspection and testing procedures Biaxial Flexure Strength Measurements The testing program initially set out to compare three different grades of ALON and two test temperatures (RT and 500°C). Since the material is transparent it is relatively easy to inspect for the presence of strength limiting flaws. Having not found anything of significance the next step was to examine other possible reasons for the wide variation in strengths. There were some concerns that there was damage introduced into the samples by the fixed abrasive grinding process. MD ASIF AKBARI SPA/BEM/711

22. Inspection and testing procedures Sample Set Descriptions Sample Set TEMP (°C) RH Number of Samples UDRI TEST ID Grain Size (µm) Fixed No Etch RT 21 54% 14 SMG-04-2-46 233±29 Loose No Etch RT 21 48% 15 SMG-04-2-47 252±34 Combined No Etch 21 N/A 29 N/A   Fixed/Loose No Etch 500 500 AIR 8 SMG-04-2-59 233±29             Fixed Etched RT 21 50% 16 SMG-04-2-48 233±29 Loose Etched RT 21 50% 14 SMG-04-2-49 252±34             CG ALON RT 21 75% 30 SMG-04-1-84   HP ALON RT 21 49% 29 SMG-04-1-58 309±60 LS ALON RT 21 64% 30 SMG-04-1-72 254±43 HP ALON 500C 500 AIR 30 SMG-04-1-43 309±60             2002-RT 21   28 N/A 250 2002-500C 500 AIR 31 N/A 250 MD ASIF AKBARI SPA/BEM/711

23. Inspection and testing procedures Test Matrix for ALON Biaxial Flexure Strength Measurements   Number of Samples Tested at Each Condition Material Classification Loose Abrasive Grind Fixed Abrasive Grind Mild Etch Deep Etch Test Temperatures 21°C 500°C 21°C 500°C 21°C 500°C 21°C 500°C   Surmet CG Grade (May 2004) 30 Surmet HP Grade (May 2004) 30 30 Surmet LS Grade (May (2004) 30 LS Grade (September 2004) 15 3 14 5 15 15 Raytheon Historical (2002) 28 31 MD ASIF AKBARI SPA/BEM/711

24. Inspection and testing procedures Strength and Weibull Analysis for ALON Sample Sets Sample Set AVG σ ( MPa) STDEV (MPa) Weibull Characteristic Strength σθ (MPa) Weibull Modulus Biased m Weibull * Modulus Unbiased mu R2 Surmet September (2004)             Fixed No Etch RT 700 169 750 8.5 7.7 0.982 Loose No Etch RT 753 179 811.9 5.6 5.1 0.968 Combined No Etch 727 173 777.7 7.0 6.6 0.979 Fixed/Loose No Etch 500°C 622 93 635.5 8.4 6.9 0.91 Fixed Etched RT (light etch) 422 59 451 10.1 9.2 0.951 Loose Etched RT (deep etch) 281 18 287.8 26.3 23.7 0.977 Surmet May (2004)             CG ALON RT 308 126 325.1 2.9 2.8 0.952 HP ALON RT 344 146 361.6 3.0 2.8 0.953 LS ALON RT 389 135 425.2 3.2 3.1 0.988 HP ALON 500° C 364 123 410.4 3.0 2.8 0.990 Raytheon (2002)             2002-RT 374.7 85.8 409.2 4.6 4.4 0.995 2002-500C 367.9 47.7 384.4 7.8 7.4 0.964 * The Unbiased Weibull Modulus is determined using Table 1 in ASTM C1239-94a. An unbiasing factor is used to best estimate the Weibull Modulus for small data sets. The factor approaches 1 as the # samples > 40. MD ASIF AKBARI SPA/BEM/711

25. Inspection and testing procedures Weibull Failure Probability Distribution for HP-ALON (May 2004) Tested at Room Temperature MD ASIF AKBARI SPA/BEM/711

26. Inspection and testing procedures Sample Test Specimen Photo of fracture test disc #119 (LS-Grade, May 2004 group) and an optical micrograph of the etched sample near the fracture origin. Strength: σ f = 197 MPa and Average Grain Size = 277 μm . Scratches on the sample near the fracture origin are revealed by etching. MD ASIF AKBARI SPA/BEM/711

27. Inspection and testing procedures Surface roughness Surface roughness measurement is done using a ZYGO NewView 100 optical profilometer. These were measured for samples from the two etch groups and an un-etched sample from the high strength group. The most deeply etch surface sample has a roughness PV roughness of 5.0 μm and an Ra of 0.657 μm compared to a PV roughness of 2.44 μm and an Ra of 0.215 μm for the lightly etched sample. The Ra of the “super” polished samples is 10 Å and the PV roughness is 30 nm. The lower surface roughness “super” polished sample group has the highest strength and the increased roughness caused by etching lowers the strength accordingly. The greater etch depth smoothes out the distribution of larger subsurface flaws introduced by machining and creates a new controlled distribution of larger flaws that lowers the average strength but increases the Weibull modulus. MD ASIF AKBARI SPA/BEM/711

28. Inspection and testing procedures Surface roughness of polished and etched ALON biaxial flexure test samples. MD ASIF AKBARI SPA/BEM/711

29. Inspection and testing procedures Surface roughness of polished and etched ALON biaxial flexure test samples. Sample Set Measured Average Strength ( MPa ) Weibull Modulus Calculated Flaw Size ( µm) Measured PV Surface Roughness (µm) Measured Grain Size (µm) Polished Fixed Abrasive 9/2004 700 ±169 7.7 12 0.030 233±29 Mild Etch Fixed Abrasive 9/2004 422 ±59 9.2 32 2.44 233±29 Deep Etch Loose Abrasive 9/2004 281 ±18 23.7 73 5.04 233±29 Sample #119 from LS-Group 197( individual)   148 scratched 277±48 LS-Group May 2004 testing 389 ±135 3.1     254±43 Predicted Flaw Size for ALON Fracture Test Samples Compared to the Surface Roughness MD ASIF AKBARI SPA/BEM/711

30. Construction specifications and working details It comes in 1 ft x 1.5 ft panels. Large ALON® window with invisible engineered seams. MD ASIF AKBARI SPA/BEM/711

31. Codes and standards Codes Governing to different properties of Transparent Aluminium Properties Codes elastic properties ASTM C1259-01 Young’s Modulus ASTM C1499-03 Poisson’s Ratio ASTM C1259-01 Weibull distribution ASTM C 1239-94a Weibull Modulus ASTM C1239-94a Laser Flash Diffusivity ASTM E1461 MD ASIF AKBARI SPA/BEM/711

32. Material and execution cost Glass costs about $3.25 per square inch, while ALON runs between $10 and $15 per square inch, he said. But in the long run, the new transparent armor could save money. Because it is lighter than glass, it would significantly reduce the dead weight and hence the overall construction cost of frame if produced on a large scale in future. MD ASIF AKBARI SPA/BEM/711

33. Material Cost (Continued) MD ASIF AKBARI SPA/BEM/711

34. Conclusion (Transparent Aluminium ) use in large windows will require significant investments in manufacturing technology and test and evaluation to demonstrate the required protection factors, especially against a multi-hit threat. Note that “large size” is a relative term. If in future it can be produced commercially on a large scale with cheaper cost, then this will define building construction specially for tall buildings, at present the cost of ALON is 5 times that of Glass-ceramic per square unit area. The cost and dead weight reduction will create new possibilities for tall structures at the same time the structural strength will increase significantly. As the density of ALON is 3.7 g/cc as compared to glass 2.7g/cc but strength wise glass is no where comparable to ALON, so the façade can itself work as load resisting and stiffening membrane. This will be the future scope of work for researchers. MD ASIF AKBARI SPA/BEM/711

35. THANK YOU MD ASIF AKBARI SPA/BEM/711