干球磨处理返回料生产硬质合金的工艺研究

The Technical Study on Producing Cemented Carbide with Recycling Materials by the Dry Grinding

本文以硬质合金返回料(废压坯破碎后的产物)为原料,采用干球磨工艺对返回料进行处理,研究了干球磨参数对粉末料(干球磨处理返回料的最终产物)的压制压力和粉末料合金的微观组织结构、物理力学性能的影响,并探索采用干球磨工艺处理返回料时,合金钴磁调控的工艺。研究结果表明:干球磨能降低粉末料的压制压力,随着干球磨时间的增加,粉末料的压制压力逐渐降低,干球磨10 h,压制压力约为25.0 kN,相对于干球磨1 h的压制压力,下降21.1%,相对于喷雾料的压制压力,下降28.6%;干球磨处理的主要目的是对返回料中的团粒进行充分破碎,宜采用高球料质量比和较短的干球磨时间,采用球料质量比12∶1,干球磨时间2 h,粉末料合金的微观组织结构和物理力学性能可与原生喷雾料合金的微观组织结构和物理力学性能相近;干球磨处理返回料时,可以采用补C操作,实现对合金Com的调控,合金的钴磁与补C量符合“合金碳量变化0.01%,钴磁相应变化0.1%”的规律。

In this paper,the cemented carbide recycling materials(the product of crushed green compact)are used as the raw materials and processed by dry grinding.The influence of dry grinding parameters on the compaction pressure of the powder materials(the final product of recycling materials by dry grinding),the microstructure,physical and mechanical properties of the alloy prepared with the powder are studied,Moreover,the process of cobalt magnetic control of the alloy are also investigated.The results show that the pressing pressure of the powder materials reduces after dry grinding.As the dry grinding time increases,the pressing pressure of the powder materials gradually decreases.The pressing pressure of dry grinding for 10 h is about 25.0 kN,which is 21.1%lower than that of dry grinding for 1 h,and 28.6%lower than that of spray materials.The main purpose of dry grinding is to fully crush the agglomerates of the recycling materials,and high ball-to-powder ratio and shorter dry grinding time are the best choices.With ball-to-powder ratio of 12∶1 and dry grinding time of 2 h,the microstructure,physical and mechanical properties of the alloy prepared with the powder can be equivalent to those of the alloy produced with original spray material.When the recycling materials are processed by dry grinding,the adjustment of the cobalt magnetic can be carried out by adding carbon.The cobalt magnetic of the alloy accords with the amount of carbon supplement:the alloy carbon content changes by 0.01%,the cobalt magnetic changes correspondingly by 0.1%.