Optimization Studies of AC4CH Material in the Cylinder Block of a Diesel Engine Application

Round 1

Reviewer 1 Report

Review on

“Optimization Studies of AC4CH Material in the Cylinder Block of a Diesel Engine Application”

by

Park et al.

(manuscript processes-1032782)

Submitted November 2020 to Processes

In this article, the authors study improvement of the mechanical properties of AC4CH alloy through refinement of the Si structure, grain refinement, and heat treatment. The applicability of a cylinder block fabricated with the modified AC4CH alloy in a diesel engine is discussed. The addressed problem is of interest and in scope of the journal. However, some aspects deserve clarification prior to publication. While the motivation to save weight and, thus, reduce the energy consumption by using Al alloys for cylinder blocks is straight forward and the results on grain refinement and alloy structure are convincing, the motivation to use an AC4CH cylinder block –without any steel sleeve inserts (!)- for a diesel engine seems doubtful, as the demonstrated 300h durability of the engine seems quite short for ‘real life’ applications, especially as an engine for a boat. Below please find my detailed comments.

Remarks:

• The development of the alloy and the characterization of the effect of processing on the resulting mechanical and structural properties are clearly described and scientifically sound. Regarding this part of the manuscript I only have to recommend to add clearly readable scaling bars to Figures 4 to12
• My only concerning is your motivation / chosen example:
• As already mentioned in the introduction, diesel engines are subjected to higher pressures than petrol engines due to compression ratios ignition and the mode of ignition by compression. In practice, if the cylinder block of a diesel engine is made of aluminum, so-called steel sleeve insets are used, i.e. the cylinder region of the Al block is steel-lined, which help to save weight (Al) and circumvent (steel-lining) many issues that would result, if these regions would be made of an Al alloy. Overall, the authors should outline and critically assess their motivation, as the issues with the aluminum alloy
• I cannot assess the observed wear / durability after 300h running the engine with the AC4CH block under the chosen load conditions. How would this compare to an engine with a cast-steel block? Further explanation is needed.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

The article is novel and of interest to the industry, it also fits into the field of the journal.

1. Why has it been tested over 300 hours, has the bibliography been followed?
2. If a sand mold has been used, I understand that the metal has been poured and not injected as shown in figure 3, it should be modified.
3. Have you quantified the surface roughness obtained by each alloy? It would be interesting

Author Response

Please see the attachment.

Author Response File: Author Response.pdf