Micromachining process with ductile tooling

这项研究旨在开发一种新的自动化制造工艺，旨在取代批量生产注塑模具制造过程中繁琐的手工抛光操作。注塑模具是一种昂贵的设备，需要以合理的价格生产，包括汽车、计算机、手机、电动工具、玩具等各种消费品中包含的任何类型的聚合物部件。注塑模具的主腔是用一台功能强大的数控铣床从工具钢材料块中雕刻出来的，然后进行二次手动加工以获得所需的表面光洁度。高达30%的模具生产成本与后一种二次精加工工艺有关，因为这些操作大多涉及手工。在拟议的研究中，我们的目的是设计一种自动化制造工艺，基于EDµM电火花微细加工和UA微米超声磨料微细加工原理。在EDµM中，在刀具和待抛光的工件之间产生放电。每一次放电都会攻击表面，并蒸发少量的物质。对于UAµM，超声波激活的刀具产生强大而微小的位移，将磨粒推进到工件表面，从而去除或移动少量材料。这种方法的新颖性在于有可能在同一台数控机床中结合这两种工艺的优点。这种特性是通过开发一种延展性、导电性和耐磨性的聚合物工具来实现的，这种工具一旦模压成型，就可以用作在最硬的金属中执行任一材料去除技术的工具。整个过程是环保的，因为它是在空气中或与磨粒(如沙子)进行的，不会产生有毒副产品。在加拿大，模具制造代表着一项价值30亿至40亿美元的业务，来自新兴国家的竞争非常激烈，因为工资较低。因此，拟议的研究努力使我们的模具制造业重新获得全球竞争优势。

The proposed research is about the development of a novel automated manufacturing process designed to replace tedious hand-polishing operations involved in the fabrication procedures of mass production injection molds. Injection molds are expensive pieces of equipment required to produce at reasonable price, any kind of polymer parts contained in a large variety of consumer products such as cars, computers, cell phones, electric tools, toys and others. The main cavity of an injection mold is carved out of a block of tool steel material with a powerful CNC milling machine, followed by secondary manual processes to obtain the desired surface finish. Up to 30% of the mold production cost is related to the latter secondary finishing processes because most of these operations involve handwork. In the proposed research our intention is to design a automated manufacturing process, based on the EDµM electric discharge µmachining and UAµM ultrasonic abrasive µmachining principles. In EDµM, electric discharges are produced between a tool and the workpiece to be polished. Each discharge attacks the surface peeks and vaporise tiny amount of the material. For UAµM, an ultrasonic activated tool generates powerful yet small displacement to propel abrasive particles over the surface of the workpiece which removes or displaces tiny amount of material. The novelty of this approach resides in the possibility to combine the advantages of both processes within the same numerically controlled machine tool. Such characteristic is made possible by the development of a ductile, electrically conductive and wear resistant polymer tool which, once compression molded can be used as a tool to perform either material removal techniques in the hardest metals. The entire process is environmentally friendly since it is conducted in air or with abrasive particles (like sand) and does not generate toxic by-products. Mold manufacturing represents a 3 to 4 billion dollars business in Canada, and competition from emerging countries is fierce because of lower wages. Thus, the proposed research endeavours giving back a worldwide competitive edge to our mold manufacturing industry.