Commercially pure titanium can take up to six months to successfully manufacture a six-inch in diameter ingot in which can be shipped to be melted and shaped into other useful components. The applications to the corrosion-resistant, light weight, strong metal are endless, yet so is the manufacturing processing time. At a cost of around $80 per pound of certain grades of titanium powder, the everyday consumer cannot afford to use titanium in the many ways it is beneficial simply because the number of processing steps it takes to manufacture consumes too much time, energy, and labor. In this research, the steps it takes from the raw powder form to the final part are proposed to be reduced from 4-8 steps to only 2 steps utilizing a new technology that may even improve upon the titanium properties at the same time as it is reducing the number of steps of manufacture. The two-step procedure involves selecting a cylindrical or rectangular die and punch to compress a small amount of commercially pure titanium to a strong-enough compact for transportation to the friction stir welder to be consolidated. Friction stir welding invented in 1991 in the United Kingdom uses a tool, similar to a drill bit, to approach a sample and gradually plunge into the material at a certain rotation rate of between 100 to 2,100 RPM. In the second step, the friction stir welder is used to process the titanium powder held in a tight holder to consolidate into a harder titanium form. The resulting samples are cut to expose the cross section and then grinded, polished, and cleaned to be observed and tested using scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS), and a Vickers microhardness tester. The results were that the thicker the sample, the harder the resulting consolidated sample peaking at 2 to 3 times harder than that of the original commercially pure titanium in solid form at a peak value of 435.9 hardness and overall average of 251.13 hardness. The combined results of the SEM and EDS have shown that the mixing of the sample holder material, titanium, and tool material were not of a large amount and therefore proves the feasibility of this study. This study should be continued to lessen the labor, energy, and cost of the production of titanium to therefore allow titanium to be improved upon and be more efficient for many applications across many industries.

Abstract When producing ferrochrome, a submerged arc furnace (SAF) is used. The charge of an SAF consists of chromite pellets, coke, lumpy ore and quartzite as a slag modifier. The charge is pre-heated before it descends into the SAF where the charge eventually reduces and melts. The electrical conductivity of the charge is important because, among other things, it affects the productivity of the furnace. The electrical conductivity of the charge should ideally be low on the higher parts of the furnace and high near the electrode tip. This is to ensure that the electric current path travels through the metal bath via arcing, which provides the most effective heat transfer. Another option for the current path would be through the solid feed material via ohmic conduction, but since this zone is less reactive, the heat energy would be mostly wasted. This work brings forth new information about the electrical behaviour of coke and chromite pellet is produced. The electrical conductivity was measured at room temperature for different simulated process conditions (different coke textures, different reduction degrees of chromite pellets, sulphur in atmosphere and replacing the coke used in chromite pellet production with charcoal). It was found out that unlike gasification with a CO/CO2 mixture, heat treatment at 950°C increased the degree of graphitization and changed the electrical behaviour of coke. Furthermore, it was observed that increasing the chromite pellets’ reduction degree reduced the electrical conductivity measured at room temperature. In the case of chromite pellets and sulphur in the atmosphere it was found that sulphur has an effect on the pellets’ electrical behavior and structure during reduction, which - in turn - has an effect on the SAF performance when raw materials with varying sulphur contents are used. Lastly, it was found that substituting coke with charcoal when producing chromite pellets affects the sintering behaviour, cold compression strength, and electrical conductivity of the chromite pellets. / Tiivistelmä Uppokaariuuni on osa ferrokromin valmistusprosessia. Uppokaariuuniin panostetaan kromiittipellejä, koksia, palarikastetta ja kvartsiittia. Etukuumennusuunista panos laskeutuu uppokaariuuniin, jossa se pelkistyy ja lopulta sulaa. Uppokaariuunin panoksen sähkönjohtavuus on tärkeää uunin toiminnan kannalta, koska se vaikuttaa suoraan esimerkiksi tuottavuuteen. Jotta virran kulku tapahtuisi optimaalisesti sulan metallin kautta, panoksen sähkönjohtavuuden tulee olla pieni uunin yläosissa ja suuri alaosassa lähellä elektrodien päitä. Mikäli virran kulku tapahtuu uunin yläosassa, hukataan lämpöenergiaa ja uunin toiminta hankaloituu. Tässä työssä on selvitetty koksin ja kromiittipellettien sähköisiä ominaisuuksia. Sähkönjohtavuutta on tutkittu useilla simuloiduilla prosessiolosuhteilla (koksin eri tekstuurit, kromiittipellettien eri pelkistysasteet, rikin pitoisuus atmosfäärissä ja kromiittipellettien valmistuksessa on korvattu koksi puuhiilellä). Nämä mittaukset on tehty huonelämpötilassa. Huomattiin, että toisin kuin koksin kaasutus, koksin lämpökäsittely (950°C) nosti grafitoitumisastetta ja vaikutti sähköisiin ominaisuuksiin. Kromiittipelletin pelkistymisasteen noustessa huonelämpötilassa mitattu sähkönjohtavuus laski. Kun kromiittipelletit altistetaan atmosfäärille, jossa on rikkiä, pellettien sähköiset ominaisuudet muuttuvat samoin kuin rakenne pelkistyksen aikana. Tämä vaikuttaa uppokaariuunin toimintaan, kun käytetään raaka-aineita, joissa rikkipitoisuus vaihtelee. Kun kromiittipellettien valmistuksessa käytettävä koksi korvataan puuhiilellä, tämä vaikuttaa sintrausprosessiin, kylmälujuuteen ja sähköisiin ominaisuuksiin.

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