Analysis of differential speed roll compaction of metal powder by upper bound method: Analysis of differential speed roll compaction of metal powder (2nd)

摘要

An analysis of the differential speed roll compaction of metal powder is carried out using the upper bound method to clarify process characteristics. An electrolytic copper powder is used for which the material constants in the constitutiveequation are well determined. The total energy dissipation rate obtained for differential speed roll compaction of metal powder in the 1st report is utilized. A minimization technique of the total dissipation energy rate involving arbitrary variables ispresented under given rolling conditions. The effects of influential factors such as roll speed ratio, initial roll gap and powder feed rates on rolling load, strip thickness and relative density are discussed. By combining with mill spring, we canpredict rolling load, thickness and relative density of the compacted strips. The predicted results agree well with experimental results obtained under carefully controlled powder feed rate. The availability of the proposed admissible velocity field isthus confirmed.