(上海交通大學(xué) 材料科學(xué)與工程學(xué)院，上海 200030)
摘 要: 設(shè)計了一種新的合金熱裂行為測試系統(tǒng)。該系統(tǒng)通過數(shù)/模轉(zhuǎn)換，用微機(jī)對凝固過程中的溫度、 應(yīng)力和收縮信號數(shù)據(jù)進(jìn)行采集和進(jìn)一步的處理，并描繪其曲線。實驗結(jié)果表明，在正常凝固條件下，AZ91合金并不按平衡相圖凝固，而是有共晶相析出；在合金凝固后期，存在一“沖擊”收縮，是“沖擊”收縮導(dǎo)致了合金凝固過程熱裂的產(chǎn)生。
關(guān)鍵字: 微機(jī)測試； 熱裂； 收縮； 凝固
hot-cracking testing of alloys
（School of Materials Science and Engineering,
Shanghai Jiaotong University， Shanghai 200030, P.R.China）
Abstract:A new method to test hot-cracking in metallic alloys was proposed. Through A/D conversion, the information of temperature, stress and shrinkage are collected and further treated, and their curves are drawn with microcomputer. The results indicate that AZ91 alloy does not solidify following the phase diagram under the experimental conditions, but precipitate eutectic; at the end of the alloys solidification, a “shock shrinkage” occurs, whcih leads to the hot cracking.
Key words: microcomputer testing; hot cracking; shrinkage; solidification
