#phaseposting

[mantaphase]

i have to wonder whether the gop propaganda machine knew they were walking on eggshells. it was their propaganda that ruined his biden's image, which made people lose faith in him, which, when combined with the effects of his declining health, finally made him realize he couldn't do it. the gop's job was to a) fuck him over enough to split the vote and b) make sure he made it to november. and they went so hard on the incompetency angle that they tipped the balance and now they have to deal with harris. like. how do you fuck up that bad. i hope all the red hats on Truth Social™ calling for biden to drop out are satisfied with this outcome

[mantaphase]

"oh, hush," i say to the alarm system going LIVING ROOM GLASS BREAK when i drop a knife

“really?” I say to inanimate objects that are not working like they usually do

[mantaphase]

OH SHIT I HAVE POLLS

[materialsscienceandengineering]

The Neodymium-Iron-Boron Ternary System

Phase Poll #10 wrapped up yesterday with the final result as 42.5% Fe, 30% Nd, and 27.5% B. This ternary system is most well known for neodymium-iron-boron magnets, so we’re going to spend a little bit of time discussing those before we narrow in on the chosen composition.

Nd-Fe-B magnets are permanent magnets with the composition of Nd2Fe14B, considered to be an intermetallic, and a tetragonal crystal structure. (Permanent magnets are those materials which are magnetized and create their own magnetic field, such as refrigerator magnets.) These neodymium magnets are the most widely used rare earth magnets and have numerous applications, including in computers, speakers, door locks, electric generators, among countless others. These magnets are typically produced either through powder metallurgy and sintering, or through melt spinning.

The chosen composition results in another stoichiometric, intermetallic phase, NdB4. Its space group is P4/bmb, meaning it crystalizes with a tetragonal crystal structure as well. On their own, there is little interest in neodymium boron compounds in the literature.

Sources/Further Reading: ( 1 ) ( 2 - image 2 ) ( 3 - image 3 ) ( 4 - images 4 and 5 )

More phase diagrams: ( image 1 ) ( 500K ) ( 1000K ) ( 1500K ) ( 2000K )

[phasepandemonium]

really liked how much spiderverse leans into cringe. being a teen is akward and weird and you say dumb things and you cant talk about your feelings right and your relationship with your parents is fucked up. cringe is the battering ram it uses to open you up

[mantaphase]

you know sometimes im a little disappointed that there's only so many "this would happen on seinfeld" posts out there and i can't make my own since i havent watched the show but. i just realized. i can watch the show. just imagine how many seinfeld-like situations there are in seinfeld. untapped potential

[materialsscienceandengineering]

The Iron-Nickel-Chromium Ternary System

Despite the labeling of the phase diagram from Phase Poll #8, the Fe-Ni-Cr diagram isn’t strictly a diagram of stainless steel compositions. True, stainless steels are iron based alloys containing both nickel and chromium in varying amounts, but if we move to the nickel side of the phase diagram, for example, we start moving toward nickel-based superalloys, not steels, which by definition are predominantly iron. Which isn’t even taking into account the numerous other elements present in steels and the other alloys touched upon by this system, including manganese, molybdenum, titanium, aluminum, etc.

Alloys within this space include the following (all compositions are approximate averages of the many alloys within each category):

Austenitic stainless steels usually have around 18% Cr and 10% Ni, sometimes with some Mo or Ti. Ferritic stainless steels and martensitic stainless steels usually have around 16% Cr, but they don’t always even contain nickel. Duplex stainless steels have around 25% Cr and lower Ni at around 5%, in addition to some Mo. Precipitation hardening steels again have around 16% Cr, but can vary widely in their Ni content, from 5-25%. Moving away from steels, Ni-based superalloys such as Inconels can have 15-30% Cr and 5-10% Fe, with the balance as nickel. High chromium alloys, however, aren’t common. While chromium is added for it’s corrosion resistance, Cr is has a BCC crystal structure, which, while strong, isn’t as ductile as the FCC structure favored by Ni*.

That means the composition chosen by the poll, 42% Cr, 36% Fe, and 22% Ni, isn’t really going to be found in any commercial alloys. However, we can discuss the microstructure at that composition, which just barely stays in the Cr + γFeNi region of the phase diagram at that temperature. γFeNi, or the gamma phase, is a disordered solid solution FCC structure that forms the matrix of most Fe-Ni superalloys, though you typically need slightly more Ni than we have to stabilize the phase. The Cr phase here is also sometimes labeled as α’, and it is a Cr-rich BCC phase (where α would be the Fe-rich BCC phase).

Sources/Further reading: ( 1 ) ( 2 - image 2 ) ( 3 ) ( 4 )

Image sources: ( image 3 ) ( image 4 )

More phase diagrams: ( image 1 ) ( Cr-Fe-Ni, 500K ) ( Cr-Fe-Ni, 1000K ) ( Cr-Fe-Ni, 1073K ) ( Cr-Fe-Ni, 1473K ) ( Cr-Fe-Ni, 1500K ) ( Cr-Fe-Ni, 2000K ) ( Cr-Fe-Ni, liquidus projection ) ( Cr-Fe ) ( Cr-Ni ) ( Fe-Ni )

* A note on the BCC vs FCC structure comparison. Astute readers will note that Fe also has a BCC structure at room temperature, lending strength but not ductility. However, at high temperatures, Fe transitions to the FCC structure, and this FCC structure can be maintained in the final product if the alloy is cooled fast enough. Take a look at the Fe-Ni phase diagram as compared to the Cr-Fe phase diagram linked above. Ni, as an FCC metal itself, helps stabilize Fe in the FCC structure at high temperatures. Cr, on the other hand, does not. So a high Cr alloy would lend itself to a BCC structure, with low ductility, which is why they are not prevalent.

Additional reading.

[mantaphase]

TO DO

mansplain

manipulate

manwhore

[materialsscienceandengineering]

The Magnesium-Zinc Binary System

Phase Poll #5 has concluded - and nobody pointed out the glaring error I made! The phase diagram is for the magnesium (Mg)-zinc system, even though I typed out manganese (Mn) for some reason. So, I’m just going to pretend that you all would have voted as much for magnesium as you did for manganese! The final result was the composition above (41 mol% Zinc; 59 mol% Mg), with no specific votes for temperature.

The numerous intermetallics formed in this binary system are not well studied, but we’ll discuss what is known! Along that compositional line, we encounter the following phases as we decrease in temperature: liquid, C14 Laves (MgZn2), Mg2Zn3, Mg12Zn13, Mg51Zn20 and an HCP solid solution of the two elements. Of the above listed intermetallics, the crystal structures of MgZn2 and Mg51Zn20 are known (space groups numbers 164 and 71, respectively). Data about other phases, such as entropy and enthalpy of formation has been calculated, however I couldn’t find any structural information.

If we approach the alloy space from the perspective of magnesium with zinc added, magnesium is a common material used for its light weight and its biodegradability in the form of metallic implants. (Magnesium can be dissolved after implantation, eliminating a need for a second surgery to remove an implant.) As zinc is also biocompatible, the combination of these two elements in medical technology is an area of interest. The addition of zinc to magnesium, generally speaking, increases strength but induces brittleness. Alloys near the middle of the phase diagram also form significant intermetallics, adding to this effect.

Sources/Further Reading: ( 1 ) ( 2 - image 2 ) ( 3 ) ( 4 )

More phase diagrams: ( image 1 ) ( in atomic/weight percent )

[mantaphase]

so at launch we had a canon bi man, a canon gay man, and a canon nb person. in a mainstream battle royale that people play at international tournaments. three queer player characters. and then they just KEPT ADDING MORE?????

catalyst explicitly mentions being trans in one of her quips. she says the word "trans". if god hates the queers why do we keep winning

[materialsscienceandengineering]

Intermediate Compounds and the Nickel-Uranium Binary System

Phase Poll #11 concluded yesterday with a fairly even split between nickel (53%) and uranium (47%). We also got one vote for a temperature of 1000K, thanks to @grimmtaupe. The Ni-U diagram is really only considered in the space of nuclear alloys, and isn’t very popular even then, so we’re going to spend some time on this post talking about intermediate compounds.

I’ve already briefly discussed congruently melting compounds vs. incongruently melting compounds, after the conclusion of phase poll #7. These definitions focus on phase transitions, while defining intermediate compounds starts to delve into the realm of solid solubility. Uranium and nickel have very low solid solubility below ~600°C (or ~873K). This can be seen from the numerous vertical lines on the phase diagram, each of which represents a specific intermediate compound, defined as simply phases with compositions that fall between two neighboring phases. Intermediate compounds almost always have a different crystal structure than the neighboring phases as well.

Solid solutions, on the other hand, can be continuous (like in the Ni-Cu phase diagram), primary/terminal (the fcc Ni phase and the bcc U phase at either side of the Ni-U phase diagram), or intermediate (like the hcp phase in the Ag-Al phase diagram). The primarily vertical lines on a phase diagram can thus give a visual indication of the solid-solubility of two elements across their compositional space.

Back to the chosen composition, our alloy would be primarily Ni9U7. Not much is known about this compound, but the thing about phase diagrams is that they’re difficult to create, even if computational tools have accelerated the process in modern times. Some research (ref. 3 below) into nickel-uranium alloys suggests that the phase is actually U10Ni13, and crystalizes in a monoclinic crystal structure. If we consider the temperature as well, we can see from our previous definitions that Ni9U7 is an incongruently melting compound. For the nickel uranium system in general, small additions of nickel have been shown to promote sintering of uranium carbides.

Sources/Further reading: ( Ni-U: 1/image 2 ) ( Ni-U: 2 ) ( Ni-U: 3 ) ( Phase diagrams: 1 ) ( Phase diagrams: 2 ) ( Phase diagrams: 3 )

More phase diagrams: ( image 1 ) ( weight and atomic percent nickel, 1 ) ( weight and atomic percent nickel, 2 ) ( weight and atomic percent uranium )

[mantaphase]

majora's mask (moonfall again)

List Of Media Where Something Fucked Up Happens To The Moon

despicable me (moon theft)

miraculous ladybug (moon split in half)

hermitcraft (moon big)

feel free to add

[mantaphase]

actually i cant imagine anything right now im sleepy dehydrated

[materialsscienceandengineering]

The Nickel-Zinc Binary System

Phase Poll #13 concluded yesterday with a pretty even split between the two elements. Nickel got slightly more votes with 51.5%, and zinc slightly less with 48.5%. Before we move into the properties and applications of nickel-zinc alloys, let’s talk a little about what we’ve already learned about phase diagrams.

From the left and right sides, we can see that zinc is fairly soluble in nickel, but that nickel is not soluble in zinc. We can also tell, without knowing anything about the periodic table, that zinc and nickel are close to each other, given that the atomic and weight percents are fairly similar. Despite their proximity on the periodic table though, we can see from the phase diagram they have vastly different melting temperatures, with zinc melting at over 1000°C less than nickel.

The primary application of this binary system is in corrosion-resistant coatings. While pure zinc coatings were once more common, small amounts of nickel help to increase the corrosion resistance. These coatings usually contain around 85% zinc or 15% nickel, resulting in the γ phase shown in the above diagram. Not only does this phase provide better corrosion resistance, but it is more ductile as well, allowing for easier coating. However, nickel remains much more expensive than zinc, limiting applications of such coatings.

The middle of the phase diagram is less well studied, and alloys with equal parts nickel and zinc are uncommon. It is known that the β1 phase crystalizes with a CuAu type structure.

Sources/Further reading: ( 1 - image 1 ) ( 2 - image 2 ) ( 3 - images 3 and 4 ) ( 4 ) ( 5 )

More phase diagrams: ( mole fraction ) ( mole fraction and mass fraction )

[mantaphase]

NO MATTER HOW THE REST OF THE YEAR GOES WE CAN REST KNOWING WE KILLED THE BEAST

[mantaphase]

bee pictured is not californian.

news is good sometimes.