본 연구개발은 2m 이상 대형 석재에 대한 가공기계 개발에 관한 것으로서, 종전에 강철재 원형톱을 회전시켜 석재를 절단하던 방식을 개선하여 와이어에 공업용 다이아몬드를 장착한 와이어 쏘우를 절단도 구로 채용하였다. 또한 부수장치로 거대 석재를 전후좌우 및 회전이 가능하여 다각도 가공이 가능하도록 턴테이블식 공작물 베드를 설계 및 개발하였다. 한편 대형 석재 가공기계는 대부분 중국산 기계가 수입되어 사용되어지고 있으며, 이로 인한 장비 관리 및 사용에 있어서 여러 가지 불편한 점들이 산재해 있으나 국내 생산 제품이 전무하여 불편함을 감수하면서 어렵게 국내 석재산업을 유지하여 오고 있는 실정이다. 따라서 본 개발을 통해서 국내 석재산업의 활성화를 기대해 본다.

Saw wires have been widely used in industries to slice silicon (Si) ingots into thin wafers for semiconductor fabrication. This study investigated the microstructural and mechanical properties, such as abrasive wear and tensile properties, of a saw wire sample of 0.84 wt.% carbon steel with a 120 μM diameter. The samples were subjected to heat treatment at different linear velocities of the wire during the patenting process and two different wear tests were performed, 2-body abrasive wear (grinding) and 3-body abrasive wear (rolling wear) tests. With an increasing linear velocity of the wire, the tensile strength and microhardness of the samples increased, whereas the interlamellar spacing in a pearlite structure decreased. The wear properties from the grinding and rolling wear tests exhibited an opposite tendency. The weight loss resulting from grinding was mainly affected by the tensile strength and microhardness, while the diameter loss obtained from rolling wear was affected by elongation or ductility of the samples. This result demonstrates that the wear mechanism in the 3-body wear test is much different from that for the 2-body abrasive wear test. The ultra-high tensile strength of the saw wire produced by the drawing process was attributed to the pearlite microstructure with very small interlamellar spacing as well as the high density of dislocation.