[Sennetti]

Hiya all, writing a "research paper" on metallurgy for school. Need some (a lot) of help understanding how transition metals bond, specifically from an electron configuration level.
I understand the basics of the electron sea model and SPDF sublevels (Somewhat of a hobbyist/grade 11 chem class)

My question: how do two different transition metals bond and how are these bonds reflected in the electron configuration?

Based on what I've been able to find online, my understanding is that the S-shells lose their electrons to the electron sea and the D-shells form covalent bonds. Is this correct?
^> So in practice, two chromium atoms ([Ar] 3d⁵ 4s¹) would bond by losing both 4s-shells to the electron sea and forming covalent bonds between the 5 d-shell electrons, filling and stabilizing the d-shells.
^>> Further, why I think/know this is wrong, one chromium atom ([Ar] 3d⁵ 4s¹) and one titanium atom ([Ar] 3d² 4s²) bonding like I said would cause the two atoms to form complete 3d-shells but contribute no electrons to the electron sea. I think my misunderstanding could be in how transition metals stabilize, but I'm not sure.

Likely an embarrassing question to ask if I'm as far off as I think, but there's no harm in asking. If my knowledge is fundamentally wrong and too much to explain in the comments section, links to any good resources to help me understand this would also be extremely appreciated.

[Hunter2]

Normaly metals dont make bonds each other. Metals can only make mixtures, what is called alloys.   Bonds only formed if a metal and a nonmetal react each other. In that case s-electrons of outer shell and the d- electrons of the shell below of the transition metal make bonds.

[Borek]

In most cases there is no covalent bonding in metals, just the metallic bond.

[Borek]

Normaly metals dont make bonds each other.

Metallic bond is - as a name suggests - a bond between metal atoms, so this statement is not correct.

You probably mean they don't bond by ionic nor covalent bonds.

[Sennetti]

In most cases there is no covalent bonding in metals, just the metallic bond.

One source I found, Britannica (https://www.britannica.com/science/crystal/Types-of-bonds#ref506390) states:
"A different type of metallic bonding is found in transition metals, which are metals whose atoms are characterized by unfilled d-shells. The d-orbitals are more tightly bound to an ion than the sp-orbitals. Electrons in d-shells do not wander away from the ion. The d-orbitals form a covalent bond with the d-orbitals on the neighbouring atoms."
So is Britannica wrong?

[Borek]

Electrons from the d-orbitals in the transition metals are quite close in energy to the s electrons, so I would expect the d electrons to become delocalized, and not involved in covalent bonding.

Covalent bonding can be probably involved in intermetallic compounds. They have different properties from the metal alloys - they are brittle, not ductile, which perfectly combines with the idea of the presence of covalent bonding instead of metallic bonding (there can be always some combination of both). But this is not a universal thing that happens in every transition metal alloy, it is present only in some - so Britannica is not wrong, you just treat what it says as if it was much more general than it is.

[Corribus]

Two metal atoms can form a covalent bond. There are plenty of examples, e.g. this one.

The OP may research quadruple bonds (δ bonds).

[Borek]

Two metal atoms can form a covalent bond. There are plenty of examples, e.g. this one.

Yes, but this is not the case of a bulk metal, rather a more complex molecule containing also other elements. My understanding is that the OP asks from the metallurgy POV, so about alloys and metals, not any compounds.