顯微硬度的影響
(廣東工業(yè)大學(xué) 材料與能源學(xué)院，廣州 510006)
摘 要: 采用銅模吸鑄法制備直徑為3 mm的Cu46Zr42Al7Gd5塊體非晶合金；研究Cu坯料純度對該合金非晶形成能力、熱穩(wěn)定性和顯微硬度的影響。結(jié)果表明：采用純度較低的Cu坯料，分別以25%和50%的比例替代純度較高的Cu坯料后，仍可制備直徑為3 mm的非晶態(tài)合金；當(dāng)替代比例提高到75%或更高時，合金呈現(xiàn)完全晶態(tài)相；當(dāng)替代比例為25%時，合金的玻璃化轉(zhuǎn)變溫度為669 K，晶化溫度為749 K，過冷液相區(qū)為80 K；當(dāng)替代比例為50%時，合金的玻璃轉(zhuǎn)化溫度為684 K，晶化溫度為751 K，過冷液相區(qū)為67 K；兩種替代比例(25%和50%)的合金經(jīng)573 K保溫1 h熱處理后，仍然保持非晶態(tài)結(jié)構(gòu)；當(dāng)替代比例為25%時，合金經(jīng)673和773 K熱處理后，合金由基體及彌散分布于其上的第二相組成，顯微硬度明顯提高；當(dāng)替代比例為50%時，經(jīng)673 K處理后，合金由基體及不均勻彌散分布于其上的第二相組成，顯微硬度有所提高，而經(jīng)773 K處理后，由第二相彌散分布于白色基體的白色區(qū)域和由細(xì)小白、灰兩相混合組成的灰色區(qū)域組成，顯微硬度大幅度提高。
關(guān)鍵字: Cu46Zr42Al7Gd5合金；塊體非晶；晶化熱處理；顯微組織；顯微硬度；純度效應(yīng)
（Faculty of Material and Energy, Guangdong University of Technology, Guangzhou 510006, China）
Abstract:A bulk amorphous Cu46Zr42Al7Gd5 alloy with a diameter of 3 mm was prepared by copper mould sucking cast. The effect of copper billet purity on the glass forming ability, thermal stability and microhardness of the alloy was studied. The bulk amorphous Cu46Zr42Al7Gd5 alloy with a diameter of 3 mm can be prepared using copper billet with lower purity to replace copper billet with higher purity in the proportion of 25% and 50%, while the alloy shows the characteristic of crystalline in the proportion of 75% or above. When the copper billet with higher purity is replaced with lower purity billet in the proportion of 25%, the glass transition temperature is about 669 K, the crystallization temperature is about 749 K and the supercooled region is about 80 K. When the copper billet with higher purity is replaced with lower purity billet in the proportion of 50%, the glass transition temperature is 684 K, crystallization temperature is 751 K and supercooled region is 67 K. The alloys all keep amorphous structure after heat treatment at 573 K for 1 h. The alloys in 25% proportion crystallize after heat treatment at 673 and 773 K for 1 h, which consist of substrate and second fine phase and have higher microhardness. The alloys in 50% proportion also consist of substrate and second fine phase, and have higher microhardness after heat treatment at 673 K for 1 h. There are two kinds of microstructures after heat treatment at 773 K for 1 h, white area consists of substrate and second fine phase, and grey area consists of white phase and grey phase. The microhardness increases sharply.
Key words: Cu46Zr42Al7Gd5 alloy; bulk amorphous alloy; crystallize heat treatment; microstructure; microhardness; purity effect
