Machining

Given the importance that the surface finish plays in properties such as resistance to fatigue, corrosion, wear, friction, lubrication, waterproofing, brightness, adherence, electrical and thermal conductivity, the object of the present paper is to find an experimental relationship for turning, that allows to determine the real conditions of cutting roughness, or to determine any of the conditions, laid down others and roughness specified in level.

The real roughness depends on many factors, including the structure and material of the piece; material, geometry, surface finish and wear of the tool, used machine, operation, lubrication and machining conditions: advance return, depth in passing and cutting speed.

The methodology used to conduct the investigation, is used by Taylor and his followers, to determine the relationship between the cutting speed and the factors on which it depends. To determine the relationship between the actual surface roughness and cutting conditions, fixing the rest of the parameters of test and factor whose influence is evaluate, this allows us to obtain a relation between roughness and parameter study is varied.

The following teams have been used in the experimentation:

Aluminum L-1100-O •Mecanizado

Torno compact 5 CNC of Emco, with a power of 500 w and hard metal tool.

•Mecanizado of steel F1120

Danobat lathe with a power of 25 kW and tool Sandvik, MWLNR 2020 K06 with insert WNMG060404-PF.

•Rugosímetro T-6000 Thyssen Hommelwerke, along with the software Turborugosidad for Windows package.

For the analysis of results agenda Statgraphics plus V.4.00 has been used.

The analysis of results shows significant statistical relationship between the studied variables, as well as a correlation high among the cutting speed and the constant of the model. The results show that the depth of only passing influences when working in conditions of recrecido Ridge and roughness improvement with the decline of the advance and the speedup. However do not work in conditions of minimum chips as the produced hammering worsens the surface finish. The highest machine speeds, should similarly not be used given that the roughness increases by the same imbalances.

1 Both in the aluminum, and steel, builds a relationship of type 2, with a greater than 0.7 r2, which indicates the goodness of the proposed model.

2. The knowledge of the model is important because it allows finding the coefficients for any other situation of turning finishing, making only four trials.

Leigh Mummery. Surface texture Analysis the Handbook. Hommelwerke GMBH. Mühlhausen 1992.

M. Thomas, y. Beauchamp, a. y. Youssef, j. Masounave. Effect of vibrations on surface roughness during turning process dry lathe tool. Computer & Industrial Engineering Vol. 31 1996. p.637-644