Investigating Optimum Parameters Required for Coiling Green Titanium Strips

Abstract

Titanium parts production using conventional processes is unarguably a costly process. Direct powder rolling process has shown its ability to produce titanium metal strips of various thicknesses and lengths. The present investigation aims to study the influence of process parameters such as roll gap, roll speed and roll set width and the green strip properties on the coil-ability of the strips. The study was conducted for roll gaps of 0.1 mm, 0.3 mm and 0.5 mm for varying roll speeds of 5 rpm, 10 rpm and 15 rpm. The roll set width was varied between 16 mm and 50 mm. Powders of Ti sponge 18 mesh (-1000 µm), TiHDH 100 mesh (-149 μm) and TiH2 CHI 100 mesh (-149µm) were roll compacted. Ti sponge green strips were coil-able after roll compaction at a roll gap of 0.3 mm, roll speed of 5 rpm and set widths of 16 mm and 50 mm. TiHDH green strips could not be coiled due to the brittle nature of the strips. TiH2 powder displayed poor rollability and could not be coiled. It was concluded that coil-ability is dependent on sufficient strength and ductility that the material has and strength and ductility depends on the rolling parameters used and the starting powder morphology and composition.