Variationer och kvalitetsutveckling: Vad orsakar variationer i presstrycket? - En fallstudie på Sandvik Coromant i Gimo
Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
Quality can be defined as inversely proportional to variability. Quality improvement can thus be viewed as the reduction of variability in processes and products. Variability in CTQ characteristics generally generates costs for poor quality and decreases a company’s profitability. Sandvik Coromant produces ready-to-press cemented carbide powder and carbide inserts in its factory in Gimo. One CTQ characteristic of the powder is the compaction pressure. The production personnel have noticed that the compaction pressure fluctuates and recently two compaction tools were damaged during compaction of a powder with a high compaction pres-sure. A high compaction pressure might also result in cracks in the carbide inserts or alter the compaction tools without notice, which could affect the geometry of the carbide inserts compacted afterwards.The purpose of the thesis was to examine what is causing variability in the compaction pressure.A pre-experimental study and three experiments were performed. During the pre-experimental study, secondary process data was collected and analyzed statistically. In the experiments, the impact of wolfram carbide, PRS and cobalt were examined. Wolfram carbide showed to have a rather large impact on the compaction pressure, whereas PRS and cobalt are unlikely to affect the compaction pressure. When the supplier of wolfram carbide was changed, the compaction pressure increased rather suddenly. I therefore recommend Sandvik Coromant to provide its suppliers with specification limits for wolfram carbide.
Place, publisher, year, edition, pages
2012. , 134 p.
Teknik, quality, variability, compaction pressure, statistical process control, design of experiments, Sandvik Coromant
IdentifiersURN: urn:nbn:se:ltu:diva-42256Local ID: 04bb21b9-1b7e-4593-b2b2-51f019b8b8a5OAI: oai:DiVA.org:ltu-42256DiVA: diva2:1015474
Subject / course
Student thesis, at least 30 credits
Sabic, SeadFredriksson, Maria
Validerat; 20120409 (anonymous)2016-10-042016-10-04Bibliographically approved