2005 Fiscal Year Final Research Report Summary
Microchanneling Process Using Local Reactive Infiltration
| Project/Area Number |
16560644
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Metal making engineering
|
|---|
| Research Institution | HOKKAIDO UNIVERSITY |
|---|
Principal Investigator |
OHMI Tatsuya Hokkaido Univ., Grad.School of Eng., Asso.Prof., 大学院・工学研究科, 助教授 (90169061)
|
|---|
| Project Period (FY) |
2004 – 2005
|
| Keywords | microchannel / reactive infiltration / intermetallic compound / liquid phase sintering / micro space / microreactor / microchannel heatsink / powder metallurgy |
|---|
| Research Abstract |
Powder-metallurgical microchanneling process using microscopic reactive infiltration was investigated. Titanium, nickel, iron, SUS304 stainless steel, Chromium, Niobium, molybdenum and Cobalt were used as body metals. Aluminum wires and Tin wires of diameter between 50 to 500 μm were used as sacrificial cores. In the experiments, a body metal powder compact including sacrificial core was sintered at a temperature between the melting points of the body metal (BM) and sacrificial-core metal (SM). Effects of the BM/SM combination and the sintering condition on the microchanneling behavior and the lining structure were examined. As a result, it was found that the microchanneling mechanism varies depending on the BM/SM combination.
Quenching experiments revealed that the main microchanneling mechanism is reactive infiltration for Ti/Al specimens compacted with low compressive pressure. On the other hand, a temporary blockage by a local swelling of the infiltrated region and the subsequent microchanneling by solid phase diffusion were observed in the highly compacted Ti/Al specimens. The latter microchanneling behavior was an unexpected phenomenon. The Ti-Al alloy liner was composed of titanium aluminides when the sintering time was relatively short. In contrast, the primary phase of the liner changed from titanium aluminides to titanium solid solutions when the sintering time was longer because of the progression of the aluminum diffusion.
For Ni-Al specimens, the main mechanism is diffusion through the intermetallic lining layer. The mechanism does not depend on the compressive condition of the green compacts. Microchannels were formed in the course of heating from 1273K to 1473K. Lining layers were clearly recognized at temperatures above 1073K.
The microchanneling mechanisms for various BM-SM systems were systemized with the infiltration rate of molten sacrificial-core metal and the diffusion rate of sacrificial-core metal into the base metal.
|
Research Products
(6 results)
