·450· 北京科技大学学报 1997年第5期 (3)设置预真空室可使凝固室压力在最短时间内降至预定值，既可提高测试精度，又可选 用较小的真空泵， 参考文献 I Chen X G,Engler S.Bestimmung Wasserstoffgehates und der Porositt in Aluminumlegierungen. Giesserei,1989,76(22):767~774 2 Ransley C F,Talbot D E J.The Routine Determination of the Hydrogen Content of Aluminum and Aluminum Alloys by the Hot-Extraction Method.J Inst Metals,1955-56,84:445~452 3 Rogers JA.Two New Techniques for Monitoring the Quality of Metals in Aluminum-Alloy Metals. Foundry TJ,1981(7):43~45 4 Thiagarajan M,Mallya U D.Evaluation of the Gas Content of Molten Aluminum Alloys.Trans AFS,1981,98:495~500 5《铸造有色合金手册》编写组.铸造有色合金手册.北京：机械工业出版社，1978.55~58 6 Traenkner F O.Practical Techniques in Casting Aluminum-PartII.Foundry M T,1982,110(4): 179~184 7 Semersky L P.Detecting Hydrogen Gas in Aluminum.Modern Casting,1983,73(8):38~39 Applying the Reduced Pressure Sample Density to Predict the Hydrogen Blow Hole Degree of Aluminium Alloy Casting Mao Weimin Zhong Taoxing? 1)Material Science and Engineering School.UST Beijing.Beijing 100083.China 2)Beijing Polytechnic University,Beijing,China ABSTRACT The RPS (sample solidified under reduced pressure)was made of a sand sample cup with which the conventional preheated metallic sample cup was substituted. As a result,the hydrogen blow hole degree of aluminium alloy casting can be predicted by the RPS'density and the quality of the melt can be controlled.Moreover a prevacuumized chamber is designed in the test apparatus,and the solidification chamber may reach the reduced pressure value in the shortest time so that the more exact test can be done.The properly reduced pressure of solidification with sand cup is about 11.3 kPa. KEY WORDS density,reduced pressure solidification,hydrogen blow hole,aluminium alloy.. 4 50 · 北 京 科 技 大 学 学 报 1 9 9 7年 第 5期 (3 ) 设置 预真 空室 可使凝 固室 压力在 最 短时 间 内降至 预定值 , 既可 提高 测试 精度 , 又 可选 用较小 的真 空泵 . 参 考 文 献 1 C h e n X G , E n g l e r S . B e s t i m m u n g W a s s e sr t o fs e h a et s u n d d e r P o or s i t i n lA um i n u m l e g i e unr g e n . G e s s e er i , 1 98 9 , 7 6 ( 2 2 ) : 7 6 7 一 7 7 4 2 aR n s l e y C F , T a l b o t D E J . hT e OR u it n e eD te rm i n a it o n o f hte yH dor g e n oC n te n t o f A l itm i n urn an d A lum i n um A l l o y s b y th e H o t 一 E x t’Ia c it o n M e ht od . J I n s t M e atl s , 19 5 5 一 5 6 , 84 : 4 4 5一 4 5 2 3 OR g e rs J A . T w o Ne w eT e hn iq ue s of r M o in t o ir n g ht e Qaul ity o f M e atl s i n lA tun i n um 一 lA l o y M e atl s . oF l l n d ry TJ , 19 8 1 ( 7 ) : 4 3~ 4 5 4 们五ag a r砚l an M , M a ll y a U D . E v a lua it o n o f het G a s oC n et n t o f M o let n AI ~ n u l n lA l o y s . T 仟nL s A FS , 19 8 1 , 9 8 : 4 9 5 ~ 5 0 0 5 《铸 造有 色合 金手册》 编写组 . 铸造有色合金手册 . 北京 : 机械工业出版社 , 1 9 7 8 . 5 一 58 6 T are n k l l e r F O . P m c it e al eT e 俪q ue s i n G 巧it n g lA um i n um 一 P’aIt l . oF u n dry M & T , 1 9 82 , 1 1 0 ( 4 ) : 1 7 9 一 18 4 7 S e m e sr 助 L P . 氏et e it n g yH d or g e n G a s i n lA u I1 11 n um . M ed e nr C as it n g , 19 8 3 , 7 3 ( 8 ) : 3 8 一 3 9 A P P l y i n g t h e R e d u e e d P r e s s u r e S am P l e D e n s i yt t o P r e d i e t ht e H y dr o g e n B l o w H o l e D e g r e e o f A l u m i n i u m A ll o y C a s ti n g 肠 。 琳 im i n l ) 及 o n g aT o 朋g l ) M a t e ir a l S e l e n c e a n d E n g i ne e ir n g S c h o o l , U S T B e ij i n g , B e ij i n g 10 0 0 8 3 , C hj n a 2 ) B e ij i n g P o ly te c h in e U in v e rs i ty , B e ij ing , C ih n a A B S T R A C T hT e RP S ( s a m P l e s o l i d i fl e d u n d e r re d cu e d P re s s u re ) w as m ad e o f a s an d s am Pl e c u P w i t h w 瓦e h t h e e o n v e n ti o n a l Pre h e a te d m e at lli e s am Pl e e u P w as s u b s it tu te d . A s a re s u l t , ht e h y d r o g e n b l o w h o l e d e g er e o f a l u m i n i u m a l l o y c a s it n g e a n be P er d i e et d by ht e RP S , d e n s i yt a n d t h e q u a li yt o f ht e m e l t c a n be e o n otr ll e d · M o er o v e r a p er v ac u u m i Z e d c h am be r i s d e s i g n e d i n th e et s t a p p a ar ut s , a n d th e 、 s o li d iif c a it o n c h a m be r m a y er ac h ht e er d cu e d P er s s u er v a l u e i n th e s h o ert s t t im e 5 0 t h a t ht e m o er e x a c t et s t e a n be d o n e . hT e Por pe ir y er d u c e d P er s s u er o f s o lid iif e a it o n w i ht s a n d e u P 1 5 a b o u t 1 1 . 3 k P a . K EY W O R D S d e n s i yt , er d u e e d P er s s u er s o li d l if e a it o n , h y d r o g e n b l o w h o l e , a l u m iin um al l o y