真空熱壓燒結壓力對Co-30 wt% Cr合金顯微組織與材料特性之研究

An Investigation of Vacuum Hot-Press Sintering Pressure Effect on the Microstructures and Material Characteristics of Co- 30 wt% Cr Alloys

張世賢(S.H. Chang) ； 林頌軒(S.S. Lin) ； 蕭翊展(Y.C. Hsiao) ； 張智堯(C.Y. Chang)

《鑛冶：中國鑛冶工程學會會刊》 61卷4期 (2017/12) Pp. 89-95

https://doi.org/10.30069/MM.201712_61(4).0008

摘要

鈷鉻(Co-Cr)合金廣泛地使用於生醫植入材料，像是人工髖關節和金屬基牙床等，因其具有優異之生物相容性、機械性質與耐磨耗性，以及特殊的麻田散體轉變及良好的加工性。此外，真空熱壓燒結是一種結合傳統燒結與加壓成形的複合式粉末冶金技術，在熱壓過程中，透過石墨模具直接將壓力傳遞至粉末，同時進行材料的壓製與燒結，此方法有助於在相對較低的燒結溫度下，形成較緻密的材料。本研究是在1150℃之燒結溫度下，進行熱壓壓力之改變(20、35與50 MPa)，針對Co-30 wt% Cr合金進行真空熱壓燒結，並對其進行一連串的分析討論。實驗結果顯示最佳的熱壓燒結參數為燒結溫度1150℃、壓力35 MPa及持壓時間1小時，此製程所生產之Co-30 wt% Cr合金具有適當之機械性質與最佳的電導率，其燒結密度增加至7.92 g．cm^(-3)，硬度和橫向破裂強度分別為77.2 HRA 和997.1MPa，而電導率為1.76×10^4 S．cm^(-1)。

關鍵字

鈷鉻合金 ； 麻田散體轉變 ； 熱壓燒結 ； 橫向破裂強度 ； 電導率

並列摘要

Co-Cr alloys have been widely used as implant materials such as hip prostheses and metal base dentures for their excellent biocompatibility, mechanical properties, wear resistance, special martensite transformation, and fabricability. Vacuum hot-press sintering is a complex method which combines the conventional sintering and pressing processes, thereby the material is directly pressed and sintered through a graphite mold to transmit the pressure onto the powder. This process produced a densified material at a relatively low sintering temperature. We conducted experiments under various hot-press pressures (20, 30, and 50 MPa) and at a hot-press sintering temperatures 1,150℃. We investigated the microstructures and characteristics of these Co-30 wt% Cr alloys. Results showed that the optimal parameters were 1,150℃ at 35 MPa for 1 h. The Co-30 wt% Cr alloys have the appropriate mechanical properties and the best electrical conductivity: sintering density enhanced to 7.92 g．cm^(-3), hardness 77.2 HRA, TRS 997.1 MPa, and electrical conductivity 1.76×10^4 S．Cm^(-1).

並列關鍵字

Co-Cr Alloy ； Martensite Transformation ； Hot-Press Sintering ； TRS ； Electric Conductivity