利用機械合金法製備播散TiC強化304不銹鋼複合合金之研究

Processing of TiC dispersion strengthened 304 stainless steel composite alloy by mechanical alloying

黃奎育(kuiyu.huang)

指導教授 ： 徐開鴻

國立臺北科技大學/工程學院/材料及資源工程系研究所/碩士(2010年)

摘要

304不銹鋼為沃斯田鐵系不銹鋼，會受熱和應力的影響而產生相轉換。在室溫下受力變形過程中會造成麻田散鐵的相變化，然後做適當的熱處理會將麻田鐵轉變回沃斯田鐵組織。
本研究試著用機械合金的方式，觀察304不鏽鋼粉的相轉換，並添加TiC強化相，探討其機械性質之差異。
本實驗以行星式球磨方式球磨304不銹鋼鋼粉，使用不銹鋼之球磨罐(250 ml)與磨球(5 mm)以BPR 15：1，球磨轉速400 rpm，在不同的球磨時間:0、2、4、6、8、10小時，並用XRD、SEM及雷射粒度分析儀觀察304不銹鋼粉的變化。
另外，以行星式球磨機將鋼粉與TiC粉末混合，使用不銹鋼之球磨罐(250 ml)與磨球(5 mm)經由400 rpm，球磨時間0、6、10小時，其TiC粉末比例分別為0 %、10 %重量百分比(相當約15 %體積百分比)，。並用XRD、SEM、密度及硬度分析觀察其機械性質之差異。
結果顯示，球磨時間2、4、6小時之304不銹鋼粉，隨著塑性應變的增加，使其顯微組織由沃斯田鐵變態為麻田散鐵。球磨時間8、10小時之304不銹鋼粉，隨著溫度升高，使其組織變回沃斯田鐵。
發現球磨時間6、10小時的304+10wt.％TiC複合合金在1335℃的燒結溫度並持溫2小時下真空燒結的相對密度為98%，達到高緻密度。複合材料的硬度值44 HRC以上，說明經過球磨製程的強化相TiC有效散布強化在304不銹鋼基地相，有效阻礙差排的滑移，明顯地提升其機械性質。

關鍵字

TiC ； 機械合金法 ； 不銹鋼 ； 金屬基複合材料 ； 真空燒結

並列摘要

304 stainless steel Austenitic stainless steel stress due to heat and stress effects phase transformation. Deformation at room temperature will cause the process of martensite phase change, then, and then make the appropriate changes in return to heat treatment will change back to austenite.
In this study, the alloy by mechanical means to try to observe the phase change of 304 stainless steel powder, and add the TiC strengthening phase, the mechanical properties of the difference.
In this experiment, planetary ball milling 304 stainless steel powder form, using stainless steel milling tank(250 ml) and balls (5 mm) with BPR 15:1, milling speed of 400 rpm, at different milling time: 0,2,4,6,8,10 hours, and with XRD, SEM and laser particle size analyzer of observed the changes in 304 stainless steel powder.
In addition to planetary ball mill to steel powder and TiC powder mixture, using stainless steel milling tank(250 ml) and balls (5 mm) by 400 rpm, milling time：0, 6,10 hours, the ratio of TiC powder were 0 %, 10% weight percentage (equivalent to about 15% volume percentage). With XRD, SEM, density and hardness of the differences between the mechanical properties observed.
The results showed that the milling time 2,4,6 小時 of 304 stainless steel powder, with the increase of plastic strain, so that by the austenitic microstructure to martensite. Milling time 8,10 小時 of 304 stainless steel powder, with increasing temperature, to bring the organization back into austenite.
Found that the milling time 6,10 hours of 304 +10 wt% TiC composite alloy sintered at 1335℃ temperature and holding temperature 2 hours under vacuum sintering relative density of 98% to high density. Shows that, after the ball milling process of the strengthening phase TiC effective dispersion strengthening phase in 304 stainless steel base, effectively hinder dislocation slip, significantly improve their mechanical properties.

並列關鍵字

TiC ； mechanical alloying ； stainless steel ； metal matrix composite ； vacuum sintering

參考文獻

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