Spin-forming Project Report

Switzner, Nathan ; Henry, Dick

关键词: ALLOYS;    ALUMINIUM;    CONCENTRATORS;    COOLANTS;    COPPER;    DEFECTS;    LASERS;    SHAPE;    STAINLESS STEELS;    TITANIUM;    TUNGSTEN;    VANADIUM;   

DOI  :  10.2172/952564
RP-ID  :  KCP-613-8550
PID  :  OSTI ID: 952564
Others  :  TRN: US200915%%102

学科分类：材料科学（综合）

美国|英语

来源: SciTech Connect

【 摘 要 】

In a second development order, spin-forming equipment was again evaluated using the test shape, a hemispherical shell. In this second development order, pure vanadium and alloy titanium (Ti-6Al-4V) were spin-formed, as well as additional copper and 21-6-9 stainless. In the first development order the following materials had been spin-formed: copper (alloy C11000 ETP), 6061 aluminum, 304L stainless steel, 21-6-9 stainless steel, and tantalum-2.5% tungsten. Significant challenges included properly adjusting the rotations-per-minute (RPM), cracking at un-beveled edges and laser marks, redressing of notches, surface cracking, non-uniform temperature evolution in the titanium, and cracking of the tailstock. Lessons learned were that 300 RPM worked better than 600 RPM for most materials (at the feed rate of 800 mm/min); beveling the edges to lower the stress reduces edge cracking; notches, laser marks, or edge defects in the preform doom the process to cracking and failure; coolant is required for vanadium spin-forming; increasing the number of passes to nine or more eliminates surface cracking for vanadium; titanium develops a hot zone in front of the rollers; and the tailstock should be redesigned to eliminate the cylindrical stress concentrator in the center.