Lubricants Based on Vegetable Oils as Effective Lubricating Agents in Sheet-Titanium Forming

Abstract

Sheet metal forming processes allow for production of lightweight and durable goods. For this reason, drawing operations have been widely used across the automotive, aviation and construction industries and for production of various components of machines. Despite the popularity of deep-drawing steel sheet metal, non-ferrous materials, such as aluminium, magnesium and titanium are also used for such purposes. Titanium materials seem to be particularly attractive due to a beneficial ratio of strength to density and excellent corrosion resistance in the most of technological environments. However, titanium and its alloys belong to a group of materials with low tribological properties and tendencies for galling and build-up of layers of the deformed material on the tool surface. Therefore, this study will discuss the results of the investigations concerning selection of technological lubricants based on vegetable oils used for the operation of forming of sheet metal made of commercially pure titanium (Grade 2). The focus of the experiment is on lubricants based on vegetable oils i.e. rapeseed oil, sunflower oil and olive oil. The main lubricating additive was boric acid and stearic acid. The study presents the results of the determination of friction coefficient during a strip drawing test.