Asp.NetMVC API前後端分離ダウンロードファイル乱符号化問題

c#コード

public HttpResponseMessage Export(){
	HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
    {
          response.Content = new System.Net.Http.ByteArrayContent(ms.ToArray());
      };

      response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/vnd.ms-excel");
      response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
      {
          FileName = Name + ".xls",
          DispositionType = "UTF-8"
      };
      return response;
}

フロントエンドコード(react+axios)

export function Post (url,params){
    return axios.post(url,params,{
        responseType:'arraybuffer'
    }).then(response =>  {
        return response;
    }).catch(error => {
        console.error(error)
    })
}
Post(url,params).then(res => {
	 const url = window.URL.createObjectURL(new Blob([res.data],
	                   //       mime  ，     mime     .xlsx                                                     
	                   {type: 'application/vnd.ms-excel;charset=utf-8'}));
    const link = document.createElement('a');
    link.href = url;
        //  header            
    let fileName = decodeURI(res.headers['content-disposition'].substring(res.headers['content-disposition'].indexOf("=")));
        fileName = fileName.substring(0,fileName.length-1);
    link.setAttribute('download', fileName);
    document.body.appendChild(link);
    link.click();
})