Development for manufacturing of functionally gradient material by friction-assisted extrusion

点击翻译按钮获取中文摘要

Various powder forming and sintering processes for producing a Ti-Al composite material have been investigated by a powder compacting process, a sintering process and a friction-assisted extrusion process of thin strip developed by the authors.When a compacted green part of Ti-10at%Al composite powder was heated at 600 C during 10 h, the Vickers hardness of the sintered material was incresed upto HV=165, because an inetermetalic compound phase between Ti and Al was formed in Ti matrix. When a green part of Ti-10at%Al was heated at 800 C during 1 h and then the sintered part was tested by a compression test, the maximum compressive true stress was about 900 MPa and the critical compressive true strain was about 0.4.When a compacted green part of Ti-90at%Al was deformed by the friction-assisted extrusion of thin strip, the thin strip had a high tensile strength of about 200-250 MPa. When a thin strip of Ti-50at%Al deformed by friction-assisted extrusion was heated at 600 C during 10 h, the Vickers hardness of the sintered thin strip was HV=200 because of formation of intermetallic compound phase between Ti and Al.It has been confirmed that functionally graident materials are possible to be manufactured by the powder forming and sintering processes in which a laminate green part is compacted from various powder mixtures and sintered, or the laminate green part is extruded by the friction-assisted extrusion and sintered.