Code

var y2Axis = new YAxisRenderer(newYAxis, lineChart.XAxis);
y2Axis.GridColumn = 2;
y2Axis.PlotLeftSide = false;
y2Axis.GridRow = 0;
y2Axis.LabelsSource = lineChart.Plot;

lineChart.ChartPanel.Columns.Add(new GridColumn());
lineChart.ChartPanel.Children.Add(y2Axis); 

Code

// defines values range; if not specified, range will be calculated from series
var axis2 = new Axis();
axis2.MinValue = 0;
axis2.MaxValue = 30000;

// series that will be mapped to second Y axis
var values2 = new double[10] { 10000, 25000, 5000, 15000, 20000, 10000, 5000, 10000, 25000, 5000 };
var values3 = new double[10] { 20000, 15000, 15000, 10000, 25000, 5000, 15000, 20000, 5000, 15000 };
var series2 = new MindFusion.Charting.DateTimeSeries(
    years, values2, years[0], years[years.Length - 1]);
var series3 = new MindFusion.Charting.DateTimeSeries(
    years, values3, years[0], years[years.Length - 1]);
series2.MinValue = series3.MinValue = series.MinValue; // for scaling dates to values
series2.MaxValue = series3.MaxValue = series.MaxValue; // for scaling dates to values
series2.DateTimeFormat = series3.DateTimeFormat = series.DateTimeFormat;
series2.CustomDateTimeFormat = series3.CustomDateTimeFormat = series.CustomDateTimeFormat;

var data2 = new ObservableCollection<Series>();
data2.Add(series2);
data2.Add(series3);

// render second Y axis
var yAxis2 = new YAxisRenderer(axis2, areaChart.XAxis);
yAxis2.GridColumn = 2;
yAxis2.PlotLeftSide = false;
yAxis2.GridRow = 0;
yAxis2.LabelsSource = areaChart.Plot;
areaChart.ChartPanel.Columns.Add(new GridColumn());
areaChart.ChartPanel.Children.Add(yAxis2);

// render second Y's series
var areaRenderer2 = new AreaRenderer(data2);
areaRenderer2.YAxis = axis2;
areaChart.Plot.SeriesRenderers.Add(areaRenderer2); 

Code

// render second Y's series
var barRenderer2 = new BarRenderer(data2);
barRenderer2.YAxis = axis2;
areaChart.Plot.SeriesRenderers.Add(barRenderer2);