If you reuse an Aluminium pan does it then require a Tevilah as it is no longer a one time use disposable pan and now is a Keli which requires Tevilah?
Not according to R' Moshe. The pans that I have used do not last long. If you don't cut a hole in them, the heat will eventually thin it out.
According to R' Moshe Shternbuch, T'Shuvot V'Hanhagot 3:259 (mis-attributed in footnote 30 of this document to 4:192), one is only exempt from immersing the vessel if he throws it out immediately after the first use. If one decides to use it more than once, or if the local custom is to use it more than once, it requires tevilah.
In 4:192, he says that when using a disposable aluminum pan in a place where many people reuse them, before you use it the first time you should decide to use it twice and immerse it. See there for reasoning and details.
In general, there is an interesting discussion amongst the various commentaries about the halachic status of aluminum with regards to immersion. Since it is not mentioned in the torah as one of the 6 metals that require immersion, different Rabbis have different opinions about whether or not aluminum Biblically requires immersion, etc. See here for a nice breakdown (but please look up the sources yourself since he seems to have gotten R' Moshe Shternbuch position wrong in 1:451).
Aluminum pans which are thrown out after use do not require tevilla.(Horav Yisroel Belsky Shlita, see L'Torah V'horah 2:page 41, Igros Moshe Y.D. 3:23, Kinyan Torah 1:51:1, Oz Nedberu 7:71, Minchas Yitzchok 5:32, Yeishiv Moshe 1:111, Teshuvos V'hanhugos 3:259, Shraga Hameir 2:83, Minchas Osher Y.D. 2:5, Divrei Chachumim page 189:37, Shalmei Moed page 515, Pischei Halacha Kashrus (Hebrew) page 60:20, Tevilas Keilim 1:7:footnote 10, 11:148, Chelkes Binyomin Y.D. 120:69)
One who wants to use an aluminum pan more than once does not need to tovel it because the Yid is the one who is making the pan into a permanent utensil.(Horav Yisroel Belsky Shlita, see Chelkes Binyomin ibid.)
The Star-K holds an aluminum pan used more than once requires tevila with a beracha.
A jews decision to use something as a vessel does not create a requirement of tevillah. Assuming that the pan didn't originally need tevillah the later decision adds no requirement.