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NiAl介金屬化合物具有高熔點、高楊氏係數、低密度及高抗氧化的特
性，使其在航太工業之高溫應用上，足以取代傳統的鎳基及鈦基超合金而
成為深具發展潛力的材料。但是，NiAl亦有室溫脆性及高溫強度不足的缺
點。為改善NiAl的性能，以往的研究中有以預先氧化法將Al2O3添加於
NiAl中，而提升了NiAl的室溫機械性質。甚至藉由控制NiAl基材的晶粒尺
寸，更進一步提升此NiAl/Al2O3複材的機械性質。為進一步瞭解此NiAl/
Al2O3複合材之高溫機械性質，本實驗吾人繼續採用預先氧化法，先調製
出NiAl/Al2O3粉末再將之熱壓燒結緻密後，分別以壓縮測試法及單邊缺口
誶法(SENB)檢討了NiAl/Al2O3複合燒結體的高溫壓縮強度與韌性。 實
驗結果顯示：含有16.5 vol%Al2O3之NiAl/Al2O3複合燒結體在600,
800及1000 K的0.2%應變量之壓縮應力值分別為867, 678及366 MPa，而僅
含微量3.4vol%Al2O3的試樣其相同測試條件下之壓縮應力值分別為621,
629, 304 MPa。即Al2O3含量愈多，其高溫壓縮強度愈強。由壓縮應力與
溫度關係圖可知：藉由夾頭速率的提升(由0.01 mm/min提升10倍至0.1mm/
min)或Al2O3含量的增加(由3.4vol%增至16.5vol%)，NiAl/Al2O3複合材的
脆韌轉換溫度(BDTT)提升了50~100 K。 利用SENB法以三點抗折方式量
測高溫破斷韌性的結果顯示：各試樣的破壞韌性值皆隨測試溫度之升高而
增加。NiAl /3.4 vol%Al2O3試樣在1000 K時具有本研究中最高的破壞韌
性值26.4 MPa.m1/2，而NiAl/16.5 vol%Al2O3試樣會因較多的Al2O3抑制
了NiAl的延展性，使其在1000 K時的破壞韌性值減為18.8 MPa.m1/2。
Nickel aluminide intermetallic compound (NiAl) has high
melting point, high strength , low density and excellent
oxidation properties. It is possible to substitute for
traditional Ni-based and Ti-based superalloys and is considered
as the most potential high temperature material for applications
in aerospace industry. However, the major drawback of NiAl is a
lack of room temperature ductility and low creep resistance.
NiAl/Al2O3powders can be prepared by preoxidizing the NiAl
powder. The mechanical properties of hot pressed NiAl/Al2O3
composites at room temperature is better than NiAl compound. By
controlling the grain size of NiAl matrix, the mechanical
properties of NiAl/Al2O3 composites were also enhanced. In this
study the high temperature strength and toughness were
investigated by compressive testing and SENB method. The
results show the compressive strength of hot pressed NiAl/Al2O3
composites containing 16.5 vol% Al2O3 is 867, 678, 366 MPa at
0.2% compressive strain at 600, 800, 1000 K individually. The
compressive strengthof samples without preoxidation is 621, 629,
304 MPa. The high temperature compressive strength increased
with incressing the content of Al2O3. The brittle to ductile
transition temperature of NiAl increased by increasing thecross
head rate from 0.01 to 0.1 mm/min or the content of Al2O3 from
3.4 to 16.5 vol% Al2O3. All fracture toughness measurement
were done in four point bending with SENB method from 600 ~1100
K. The results show that KIC values of all samplesincreased with
testing temperature increased. The NiAl/3.4vol%Al2O3
compositesshow the maximum fracture toughness of 26.4 MPa．m1/2
at 1000 K in this study. However, the KIC value of NiAl/16.5vol%
Al2O3 composites is only 18.8 MPa．m1/2.
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