Full Transcript:

What’s up guys? This is Michael with Michael Talks Metals back for more metal madness. If you find these videos useful and want to help support the channel, please subscribe, or drop a like on the video. Thank you for the support. Today we are going to continue our videos about  the Iron-Nickel  alloys that exhibit  low thermal expansion characteristics.  Specifically alloys used for making seals to glasses and ceramics.  We have discussed expansion and CTE in some detail in a prior video.  Click here if you have not seen it, video on alloys 42, 45, and 49.

These low expansion alloys are used in applications where it is critical that they  expand at a rate comparable to the other material over a range of temperature.

Glass Sealing   42, 46, and 52 alloys have a nominal Nickel content of 40.5 %, 46 % and  50.5 % respectively.

Lets compare the typical CTE from 75 deg F to 750 deg F

Glass Sealing 42                       3.4 micro inch / inch / deg F

Glass Sealing 46                       4.3 micro inch / inch / deg F

Glass Sealing 52                       5.5 micro inch / inch / deg F

CTE increases with increasing Nickel content as we have seen in the earlier videos. (Click here for invar video)

Like the Low Expansion 42,45, and 49 alloys; the Glass Sealing alloys also have an almost constant CTE over a wide temperature range . These alloys are selected by design engineers for their specific expansion characteristics and / or range of expected temperature during fabrication or in use.

Nominal Chemical Composition

42                         46                               52

Carbon ……………..      0.02 %                  0.05 %                      0.01 %

Silicon  …………….       0.25 %                  0.25 %                      0.25 %

Manganese ……..        0.50 %                  0.50 %                      0.50 %

Nickel ……………..        40.5 %                  46.0 %                      50.5 %

Iron  ……………………………………………… Balance

Is alloy 42 Magnetic? Is alloy 46 Magnetic? and Is Alloy 52 Magnetic? Yes alloy 42, alloy 46 and alloy 52 are Magnetic up to Curie Temperature

Curie Temperature:

Glass Sealing 42     716 deg F

Glass Sealing 46     860 deg F

Glass Sealing 52    986 deg F


Glass Sealing 42        .294 lbs per cubic inch

Glass Sealing 46        .295 lbs per cubic inch

Glass Sealing 52        .299 lbs per cubic inch


Typical Mechanical Properties in the annealed condition:

Tensile Strength:     75,000 psi

Yield Strength:        40,000 psi

Elongation:                30 %

Hardness:    80   Rockwell B


ASTM  F 30

As we have told our viewers many times before, specifications, prints, and part requirements can add to or alter the information we have presented to you today so for lucky # 65, never, EVER forget to CHECK THE SPECS!!!! Michlin metals is a distributor and supplier of Alloy 42, Alloy 46 and Alloy 52. If you need more info on metals, check michlinmetals.com. Thanks for watching and if you made it this far and haven’t subscribed, please consider doing so now, here. If you missed last weeks video on Low Expansion Alloys, click here. This is Michael with Michael Talks Metal. I will see you next Thursday 10am, I’m out!