硬质合金中碳含量对晶粒生长抑制剂抑制效果的影响

发布时间：2018-11-27 14:46

【摘要】：配制两批不同总碳为5.66%和5.70%的混合料,在不同烧结温度下制备WC-9Co(含0.8%的Cr_3C_2/VC)超细晶硬质合金,检测了混合料中氧含量及WC晶粒大小、应变随球磨时间的变化情况,研究了不同烧结温度下WC-9Co硬质合金的磁学性能随球磨时间的变化。结果表明,滚动球磨不能破坏晶粒尺寸达到纳米级的WC原料微观晶粒;不同总碳混合料随球磨时间延长其氧含量均呈上升趋势,符合线性规律,但高总碳的混合料中氧含量上升速度较慢;超细晶硬质合金的Com值(即碳含量)是影响H_c值的主要因素,随Com值增加H_c先升高后降低并呈抛物线规律,在特定的Com值达到最大值,据此可以推测其主要原因是硬质合金碳含量影响Cr、V元素在WC/Co界面析出形成抑制WC晶粒长大的(W,Cr)C_x和(W,V)C_x界面相,进而影响抑制效果。
[Abstract]:Two batches of mixture with different total carbon of 5.66% and 5.70% were prepared to prepare WC-9Co (containing 0.8% Cr_3C_2/VC) ultrafine cemented carbide at different sintering temperature. The oxygen content and the size of WC grain in the mixture were measured. The variation of magnetic properties of WC-9Co cemented carbides with ball milling time at different sintering temperatures was studied. The results show that rolling ball milling can not destroy the grain size of WC raw material. The oxygen content of different total carbon mixtures increased with the prolongation of ball milling time, which was in line with the linear rule, but the oxygen content in the mixture with high total carbon increased slowly. The Com value (carbon content) of ultrafine cemented carbides is the main factor that affects the value of HSCs. With the increase of Com value, HC increases first, then decreases and presents parabola law, and reaches the maximum value at specific Com value. It can be inferred that the main reason is that the carbon content of cemented carbides affects the precipitation of Cr,V elements at the WC/Co interface to form (WnCr) C _ (x) and (WV) C _ x interfacial phases which inhibit the growth of WC grains, and thus affect the inhibition effect.
【作者单位】：中南大学粉末冶金研究院;湖南博云东方粉末冶金有限公司;
【分类号】：TG135.5

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